TABLE 5: PRIMARY REPORTS FOR THE 18 APR 1906, 14:28 AFTERSHOCK SEE CORRESPONDING FIGURE 2 This aftershock occurred only hours after the mainshock, at a time when aftershocks were occurring at a high frequency. That there was a relatively large aftershock at about 14:28 on the afternoon of 18 Apr 1906 is inferred from a number of widely-spaced reports of an unusually large earthquake at around that time; nevertheless, there are reports of two or more closely-timed events from some of those locations, and in some cases it is not clear which reports describe which event. Although the preferred interpretation is that there was a single large event at around 14:28, with several smaller events a few minutes before and after, the data support an alternative interpretation: there may have been two large aftershocks, one near San Francisco at 14:25, and one near Santa Cruz at 14:28. In the table below, we use the assumption that there was only one large event in assigning the intensities at each location; if there were two large events, however, the intensities assigned below would be smaller at some locations for the earlier event, and smaller at other locations for the later event. Location Described: Alameda, Alameda Co. Report 1: Lawson (1908), vol. I, p. 413 felt at Alameda Pier MMI for this location: Uncertain Location Described: Berkeley, Alameda Co. Report 1: Lawson (1908), vol. I, p. 413 Ewing seismograph recording at 14:24:37. Another event at 14:28:50. MMI for this location: Uncertain Location Described: Antioch, Contra Costa Co. Report 1: Lawson (1908), vol. I, p. 413 felt at Antioch MMI for this location: Uncertain Location Described: Salinas, Monterey Co. Report 1: Salinas Weekly Journal, 21 Apr 1906; p. 3, c. 2-3 (Under the heading "From Thursday's Daily Journal":) "... During the day and until midnight slight shocks, to the number of twenty or more, kept our people in a state of nervous suspense. A frisky one at 2:28 sent people running pell mell into the streets." Report 2: San Luis Obispo Tribune, 20 Apr 1906; p. 1, c. 4 "Salinas April 18:-.... There were three distinct shocks here this morning followed by 3 more at 2:25 o'clock this afternoon...." Report 3: Lawson (1908), vol. I, p. 413 felt at Salinas MMI for this location: IV Location Described: Sacramento, Sacramento Co. Report 1: Lawson (1908), vol. I, p. 413 "Very light." MMI for this location: Uncertain Location Described: San Francisco, San Francisco Co. Report 1: Lawson (1908), vol. I, p. 413 Event at 14:24: "Very light." Event at 14:25: Duration 4 seconds. Lawson (1908) estimates Rossi-Forel intensity III. Event at 14:28: "Very light." MMI for this location: Uncertain Location Described: Southampton Shoal, San Francisco Co. Report 1: Lawson (1908), vol. I, p. 413 "Vertical throw north-south tremor 20s. before; no noise." Duration 5 seconds. MMI for this location: Uncertain Location Described: Stockton, San Joaquin Co. Report 1: Lawson (1908), vol. I, p. 413 "Very light." MMI for this location: Uncertain Location Described: San Simeon, San Luis Obispo Co. Report 1: Lawson (1908), vol. I, p. 299 "... at San Simeon ... the shock of the afternoon (of April 18) was also noticed, which was not the case farther south...." MMI for this location: Uncertain Location Described: Agnew, Santa Clara Co. Report 1: San Jose Mercury and Herald (combined issue), 19 Apr 1906; p. 4, c. 4-5 "The State Hospital for the Insane at Agnews lies in a mass of ruins.... The second shock that occurred about 2 o'clock terrified the rescuing parties and part of the walls of the Administration Building that remained standing fell to the ground with a crash." MMI for this location: IV ? Location Described: Los Gatos, Santa Clara Co. Report 1: Lawson (1908), vol. I, p. 413 felt at Los Gatos MMI for this location: Uncertain Location Described: Mount Hamilton, Santa Clara Co. Report 1: Lawson (1908), vol. I, p. 413 Event at 14:23:10: Lawson (1908) estimates Rossi-Forel intensity II. Event at 14:28:36: Lawson (1908) estimates Rossi-Forel intensity III. MMI for this location: Uncertain Location Described: Santa Clara, Santa Clara Co. Report 1: San Jose Mercury and Herald (combined issue), 19 Apr 1906; p. 4, c. 7 "minor shock" MMI for this location: Uncertain Location Described: Boulder Creek, Santa Cruz Co. Report 1: Mountain Echo (Boulder Creek), 21 Apr 1906; p. 3, c. 1 "There have been numerous light shocks of earthquake every day since Wednesday and on Wednesday afternoon there were two quite heavy shocks just before half past two o'clock." MMI for this location: IV ? Location Described: Scotts Valley, Santa Cruz Co. Report 1: Lawson (1908), vol. I, p. 413 "Extra hard, stopt clock hanging on wall facing south, 20" pend. Stopt clock facing NW. by WNW., pend. about 5"." Lawson (1908) estimates Rossi-Forel intensity IV. MMI for this location: V ? Location Described: "4 miles south of Wrights*," Santa Cruz Co. Report 1: Lawson (1908), vol. I, p. 413 "Slight." * The locality given in Lawson (1908) is "4 miles south of Wright's Station." According to Durham (1998), Wright's Station is an old name for Wrights, a village in Santa Clara County, near the Santa Cruz County line. Four miles south of this point would be in Santa Cruz County. MMI for this location: Uncertain Location Described: Mare Island, Solano Co. Report 1: Lawson (1908), vol. I, p. 413 Event at 14:22: "Slight." Duration 1-2 seconds. Event at 14:27: "Slight." Duration 1-2 seconds. MMI for this location: Uncertain Location Described: Modesto, Stanislaus Co. Report 1: Modesto Daily Evening News, 18 Apr 1906; p. 1, c. 4 "... another distinct shock of earthquake was felt in Modesto, being especially noticeable in the downtown business blocks...." MMI for this location: III TABLE 6: PRIMARY REPORTS FOR THE 18 APR 1906 TRIGGERED EVENT at 16:30 in the IMPERIAL VALLEY, CALIFORNIA SEE CORRESPONDING FIGURE 3 Location Described: Brawley, Imperial Co. Many newspapers outside Brawley reported the earthquake in Brawley. Some of these reports appear to be based upon reports that are listed below, and they contain no new information. Only reports with unique information are listed below. Report 1: Brawley News, 20 Apr 1906; p. 1 "Accustomed to earthquake shocks of more or less severity, the residents of Brawley gave but little heed to the shakes manifested Wednesday afternoon until at half past four, almost without warning an extremely heavy shake threw the buildings hither and thither, twisting the wooden structures until it seemed as if they must topple over and causing the walls of the brick and adobe buildings to bend outward and in many cases to crack open and fall apart. Clocks stopped, dishes fell clattering to the floor, window glass crashed, chimneys fell, and doors were forced off their hinges while the clouds of dust arising from the fallen buildings and the distant river banks attested the impotence of man in the face of the mighty displeasure of Nature. "With the many walls, bricks and timbers that were thrown to the ground, it is a matter of wonder and congratulation that no one was killed, but fortunately no one was hurt with the exception of a small boy, the son of J. M. Price, of No. 8, on whom a portion of an adobe wall fell, bruising him severely and breaking his collarbone. "The chief damage was in the heart of the town, where the Van Ness and Marlowe buildings were almost totally destroyed, the walls on three sides falling, carrying ruin in their path. In these buildings were the store of J. L. Colman, the Ideal Restaurant and the Pioneer Pool Room. The stock and fixtures in these places was somewhat injured. "The front wall of the Imperial Valley Bank fell into the street, filling with debris the room which Cashier Dunn had vacated but a moment before. The walls of Varney Bros. new brick store swayed and tottered, but finally settled back into place, with bulging corners and ends to show the effects of the shock. The office building of the Brawley Land Company was ripped open on the north. The NEWS building has a few whole panes of glass left and shows cracks on the north end large enough to admit plenty of fresh air, while the type in the galleys and on the imposing stones exceeded even the editor's experience with pi. "At the adobe Bungalow Hotel ruin reigned supreme. Hardly a square yard of plastering on the entire building's sides is left intact. The dining room walls let in the sunshine and the wind and the dormitory and the office sections fared little better. The interior resembled a sand pit rather than a hotel. The two-story brick annex, containing four sleeping rooms on the second floor and the barber shop of C. Darnell and the office of The Lyon Bros.' Co., Peter Hovley, manager, was badly wrecked. The walls on the second story bulge out and the corners, cracked for many feet, are in a precarious condition. Remnants of the big plate windows strew the sidewalk. This building has been vacated as unsafe. The laundry is a wreck, much of the walls having fallen. "Part of the brick foundation to the packing house addition must be relaid. The adobe schoolhouse has been pronounced unsafe. Miss Malan has held school in the building formerly occupied as a residence by Bert Varney. "Not one brick or adobe building in the vicinity of Brawley but what was damaged [sic]. "The house occupied by W. J. Wallace suffered considerable damage, one of the walls going down. Ruth's blacksmith shop and George J. Holloway's house were damaged. "In No. 8, the three adobe houses owned by D. S. Elder are complete wrecks. The recently built stone house on the New River Ranch occupied by J. A. Thompson, was partly demolished. "In the store buildings in town, goods of all descriptions were piled up on the floors in indescribable confusions, and china and glassware was smashed to smithereens. At Miss Pellet's restaurant not one dish was left whole. Hardly a chimney in town is standing. "As soon as the dust of the fallen debris had cleared away, ropes were stretched before the buildings in the most dangerous condition for the earthquake shocks continued at irregular intervals and have kept up until this publication although no further damage has resulted. The scene immediately following the heavy shock was one long to be remembered. From the clouds of dust emerged men, women and children, who with the tidings of the terrible calamity at San Francisco yet ringing in their ears, found themselves suddenly confronted with a similar disaster on a smaller scale. Down the street toward the crowd rushed a runaway horse, frightened by the shake, but was stopped midway in its career by E. E. Pellet. With women screaming and children crying, the first thought was for those injured, but a hurried search revealed the fact that everyone was safe. At night few lamps were lighted, through fear of a shock tipping them over. "Wednesday night the residents of most of the buildings joined the outdoor brigade and slept under the open sky. Bright and early Thursday morning work began on repairing the damage. The streets were cleared of rubbish so that by the time curious visitors from nearby towns had arrived, much of the town had again assumed a respectable appearance.... "The loss in Brawley can be repaired, temporarily, for a few thousand dollars, but many of the buildings must be rebuilt. The total damage cannot be less than $15,000, besides that in the adjoining territory. A severe shock was felt in all parts of the Imperial Valley, but Brawley was the worst sufferer, with Holtville next, for the new buildings were severely damaged. Imperial, El Centro and Calexico sustained little injury beyond a few cracked walls." Report 2: Brawley News, 27 Apr 1906; p. 4, c. 1 "A look over the results of the earthquake shows that the damage was more apparent than real. Most of the buildings damaged were of temporary construction. Not one frame building was injured and the two brick buildings that suffered loss can be repaired with little difficulty. The dust had hardly cleared away from the streets when the work of repairing and rebuilding commenced. In two or three weeks the only visible reminder of the earthquake will be a few cracked walls." The actual time and date of the earthquake at issue are not stated, although it is inferred to be the Imperial Valley mainshock on the afternoon of 18 April. Report 3: Imperial Valley Press, 21 Apr 1906; p. 5, c. 4 "Quite a severe shock of earthquake was felt in the Valley on last Wednesday afternoon about 4:25. Quite a lot of damage was done to the adobe buildings in Brawley. The Imperial Valley Bank and Bungalow Hotel were seriously shattered, and Varney Bros.' store was wrecked. A residence belonging to D. D. Pellet was also wrecked and several other buildings badly cracked...." Report 4: San Diego Union, 20 Apr 1906; p. 2, c. 4 "Los Angeles, April 19.-Reports this morning from Brawley ... state that the town was practically wiped out by the earthquake of yesterday. This is the only town in Southern California known to have suffered from the shock. Southern Pacific officials report today that the following buildings there, all brick structures, were completely destroyed: "Brawley bank, Paulin building and the principal merchandise building of the town. In addition dozens of adobe houses were razed to the ground. So far as known, there were no fatalities. "Reports received tonight show the town of Brawley to have suffered less by yesterday's earthquake shock than originally stated. About one hundred buildings in Brawley and the surrounding valley were damaged, but none of them was wholly destroyed." The writer of this report apparently did not realize that the event which affected Brawley was different from the mainshock in northern California. From other reports, the damage in Brawley is inferred to be a result of the Imperial Valley mainshock on the afternoon of 18 April. Report 5: San Diego Union, 22 Apr 1906; p. 8, c. 6 "A special dispatch to the Union last evening from the Imperial Standard implied that the damage done at Brawley was not as great as was first reported. By fixing the time, the dispatch shows that the Brawley quake was the one we felt slightly here. The dispatch was: "'Imperial, Calif., April 21.-An earthquake shock on Wednesday at 4:30 p. m. damaged adobes at Brawley. There were no casualties....'" Report 6: San Diego Union, 24 Apr 1906; p. 8, c. 3 "Calexico, April 21-At 4:30 p. m. on the 18th inst the Imperial valley was visited by an earthquake which lasted for a period of two minutes. The little town of Brawley in the north end of the valley was the worst sufferer. After the people had recovered from the first fright and started to investigate the amount of damage done, the discovery was made that not a single brick or adobe building had escaped injury and some were totally wrecked. "These are the Bungalow hotel, public school, Paris restaurant, and three adobe houses across the river in No. 8. Those damaged include the First National bank, land office, Varney Bros., C. Haack, D. D. Pellett, News office, Hutchings & Co. and Brawley Mercantile Co. "The greater portion of the people living in frame houses suffered more or less from the shaking down of dishes, lamps, bric-a-brac, etc. That no lives were lost is little short of miraculous. The only accidents reported were a woman and child injured slightly by the collapse of a dwelling across the river...." Report 7: San Diegan-Sun, 21 Apr 1906; p. 4, c. 1 "Secretary James Jasper of the chamber of commerce, has received this wire information as to the quake damage in Brawley: 'Seven buildings in Brawley were badly damaged. Some of them are a total wreck. The New river track house was destroyed. It is the total damage in the valley....'" The actual time and date of the earthquake at issue are not stated, although it is inferred to be the Imperial Valley mainshock on the afternoon of 18 April. Report 8: San Bernardino Daily Sun, 20 Apr 1906; p. 2, c. 4 [quoting a telegram from Southern Pacific Railroad Superintendent H. V. Platt, who was in the Imperial Valley at the time:] "'IMPERIAL JUNCTION, April 19.-It is reported from Brawley ... that a serious earthquake occurred there at 4:30 p. m., yesterday, and that all adobe and brick buildings were wrecked. No damage to railroad property.... "'At 5:22 p. m., it was reported from Brawley that the Brawley bank building, the Paulin building and Varney Brothers' building, all brick blocks, were ruined. No other damage reported last night....'" Report 9: Los Angeles Times, 20 Apr 1906; Part II, p. 9, c. 2 "BRAWLEY, April 19.-[Exclusive Dispatch.] The earthquake here yesterday did only slight damage and there was nothing about it to warrant the sensational reports that have been sent out magnifying it greatly. Five or six small buildings were slightly injured, but none of them was razed or even collapsed by the tremor. It caused only ordinary alarm." Report 10: Lawson (1908), vol. I, p. 414 "Northwest-southeast chimneys fell to west. Movable objects in bldgs., thrown west-east. Oscillation followed by tremors. Clock stopped at 4h 30m, facing south." Lawson (1908) estimates Rossi-Forel intensity IX.* * Based on comparison with other reports of the damage in Brawley, this estimate is clearly too high. Townley and Allen (1939) estimate Rossi-Forel intensity VIII, although even that seems to be on the high side. MMI for this location: VII-VIII (preferred: VIII) Location Described: Calexico, Imperial Co. Report 1: San Diego Union, 24 Apr 1906; p. 8, c. 3 "Calexico, April 21-.... Holtville and Calexico were shaken some but no damage was done beyond the cracking of several buildings of the former place and the post office building at the latter." Report 2: Brawley News, 20 Apr 1906; p. 1 "... A severe shock was felt in all parts of the Imperial Valley, but Brawley was the worst sufferer, with Holtville next, for the new buildings were severely damaged. Imperial, El Centro and Calexico sustained little injury beyond a few cracked walls." Report 3: Imperial Valley Press, 21 Apr 1906; p. 5, c. 4 "... No damage is reported from Calexico...." Report 4: San Diegan-Sun, 21 Apr 1906; p. 4, c. 1 "Secretary James Jasper of the chamber of commerce, has received this wire information.... "'Imperial, Calexico, Holtville and Heber are all right....'" MMI for this location: V Location Described: El Centro, Imperial Co. Report 1: Imperial Valley Press, 21 Apr 1906; p. 5, c. 4 "... Here in El Centro we all were able to notice it without great effort, and while the shock was on we felt sure things were going to happen, yet there is no damage whatever to report. Not a wall was cracked, nor was there any plaster loosened. Two bottles of ketchup were shaken off the shelves of the Valley Mercantile company, and some Breakfast Food boxes fell in Rumsey's store. No damage resulted, as even the ketchup bottles didn't break. But it was quite a lively shake just the same...." Report 2: Brawley News, 20 Apr 1906; p. 1 "... A severe shock was felt in all parts of the Imperial Valley, but Brawley was the worst sufferer, with Holtville next, for the new buildings were severely damaged. Imperial, El Centro and Calexico sustained little injury beyond a few cracked walls." Report 3: San Diego Union, 24 Apr 1906; p. 8, c. 3 "... The towns of Imperial, El Centro, and Silsbee escaped without injury...." MMI for this location: V Location Described: Heber, Imperial Co. Report 1: San Diegan-Sun, 21 Apr 1906; p. 4, c. 1 "Secretary James Jasper of the chamber of commerce, has received this wire information.... "'Imperial, Calexico, Holtville and Heber are all right....'" MMI for this location: Uncertain Location Described: Holtville, Imperial Co. Report 1: Imperial Valley Press, 21 Apr 1906; p. 5, c. 4 "... The Hotel Alamo at Holtville, was quite severely shaken and cracked. The other buildings were not seriously injured...." Report 2: Brawley News, 20 Apr 1906; p. 1 "... A severe shock was felt in all parts of the Imperial Valley, but Brawley was the worst sufferer, with Holtville next, for the new buildings were severely damaged. Imperial, El Centro and Calexico sustained little injury beyond a few cracked walls." Report 3: San Diego Union, 24 Apr 1906; p. 8, c. 3 "... Holtville and Calexico were shaken some but no damage was done beyond the cracking of several buildings of the former place and the post office building at the latter." Report 4: San Diegan-Sun, 21 Apr 1906; p. 4, c. 1 "Secretary James Jasper of the chamber of commerce, has received this wire information.... "'Imperial, Calexico, Holtville and Heber are all right....'" MMI for this location: VI Location Described: Imperial, Imperial Co. Report 1: Imperial Valley Press, 21 Apr 1906; p. 5, c. 3 "Imperial was visited by two distinct earthquakes Wednesday afternoon, the first at 3 p. m. the second at 4:20 p. m. No very serious accidents; Mr. Varney's olive oil bottles, pickles and cans got mixed up on the floor." It is not clear which of the two events mentioned was responsible for the items falling to the floor. From other reports, it is inferred that the second event was responsible. Report 2: Imperial Valley Press, 21 Apr 1906; p. 5, c. 4 "... At Imperial only slight damage was inflicted, such as knocking off plaster and cracking the walls in the brick buildings...." Report 3: Brawley News, 20 Apr 1906; p. 1 "... A severe shock was felt in all parts of the Imperial Valley, but Brawley was the worst sufferer, with Holtville next, for the new buildings were severely damaged. Imperial, El Centro and Calexico sustained little injury beyond a few cracked walls." Report 4: San Diego Union, 24 Apr 1906; p. 8, c. 3 "... The towns of Imperial, El Centro, and Silsbee escaped without injury...." Report 5: San Diegan-Sun, 21 Apr 1906; p. 4, c. 1 "Secretary James Jasper of the chamber of commerce, has received this wire information.... "'Imperial, Calexico, Holtville and Heber are all right....'" MMI for this location: VI Location Described: Imperial Junction, Imperial Co. (now Niland, CA) Report 1: San Bernardino Daily Sun, 20 Apr 1906; p. 2, c. 4 [quoting a telegram from Southern Pacific Railroad Superintendent H. V. Platt, who was in the Imperial Valley at the time:] "'IMPERIAL JUNCTION, April 19.-It is reported from Brawley ... that a serious earthquake occurred there at 4:30 p. m., yesterday, and that all adobe and brick buildings were wrecked. No damage to railroad property. There was continuous rumbling and shaking from 1:30 to 6:20 p. m., and the shocks were felt at Imperial Junction....'" MMI for this location: Uncertain Location Described: 2 miles east of Pope, Imperial Co. Report 1: San Bernardino Daily Sun, 20 Apr 1906; p. 2, c. 4 [quoting a telegram from Southern Pacific Railroad Superintendent H. V. Platt, who was in the Imperial Valley at the time:] "'IMPERIAL JUNCTION, April 19.-It is reported from Brawley ... that a serious earthquake occurred there at 4:30 p. m., yesterday.... "'A very low ledge is reported two miles east of Pope, and appears dangerous. It is believed to have been caused by the earthquake, and trains have been given orders for six miles an hour in that section, and section men have been sent out to investigate....'" This is quite a curious report. The "very low ledge ... believed to have been caused by the earthquake" could be any of a number of possibilities, and it is not inconceivable that it describes a fault scarp. The location is described as "two miles east of Pope." Pope is a locality along the Southern Pacific railroad and lies precisely on the San Andreas fault; hence, the location of this reported ledge would be within two miles of the San Andreas fault. It is also well within the likely epicentral region determined by Meltzner and Wald (2003). But there may be a more likely explanation. Between 1 and 2 miles ENE of Pope, the Southern Pacific railroad crosses over several stream channels, one of them being of a fairly significant size. It is possible that the intense shaking during the earthquake at the site caused slumping along one of the banks of the channel. A resulting erosional scarp could be the "ledge" that is described in the article. MMI for this location: Uncertain Location Described: Silsbee, Imperial Co. Report 1: San Diego Union, 24 Apr 1906; p. 8, c. 3 "... The towns of Imperial, El Centro, and Silsbee escaped without injury...." MMI for this location: Uncertain Location Described: Los Angeles, Los Angeles Co. Report 1: Los Angeles Times, 19 Apr 1906; Part II, p. 3, c. 3 "From several parts of the city reports have been received of a slight temblor shortly before 4:30 o'clock yesterday afternoon. The officials in the Federal courts at the top of the Tajo Building seemed to notice the shock most plainly, but in several other downtown buildings persons felt it slightly. In a few cases the swaying of a chandelier was the only sign noticed. No alarm was occasioned, except the apprehension that it was the tail end of another shock at San Francisco." MMI for this location: III Location Described: San Juan Capistrano, Orange Co. Report 1: Lawson (1908), vol. I, p. 414 "Slight." MMI for this location: Uncertain Location Described: Santa Ana, Orange Co. Report 1: Evening Blade (Santa Ana), 19 Apr 1906; p. 3, c. 1 "Besides the faint shock of the earthquake felt here shortly after 5 o'clock yesterday morning and noticed by a considerable number of people through out the city, another shake occurred late yesterday afternoon about 4:30, the effect of which was noticed particularly in the western portion of the city where houses were rocked perceptibly and pictures and other articles depending from the walls were swung to and fro. The disturbance lasted only a few seconds, but the jarring was so pronounced that it was readily recognized as the result of an earthquake. F. F. Thorp, a resident of West Second street was lying ill in bed at the time and he plainly noticed the swaying of the house and the vibration of pendant electric light bulbs in the room he occupied, while other residents of the locality were also apprised of the fact that a seismic disturbance was in progress by the distinct rumbling and jarring of their residences." MMI for this location: IV-V (preferred: IV) Location Described: Coachella, Riverside Co. Report 1: Los Angeles Times, 19 Apr 1906; Part II, p. 14, c. 6 "COACHELLA, April 18.-Two distinct shocks of earthquake were felt here at 4:30 o'clock this afternoon. There was no damage reported." MMI for this location: IV ? Location Described: Hemet, Riverside Co. Report 1: Lawson (1908), vol. I, p. 414 "Shock increasing and dying away." MMI for this location: Uncertain Location Described: Riverside, Riverside Co. Report 1: Lawson (1908), vol. I, p. 414 "Shock increasing and dying away." MMI for this location: Uncertain Location Described: San Jacinto, Riverside Co. Report 1: San Jacinto Register, 26 Apr 1906; p. 4, c. 1 "... At 4:20 p. m. that terrible day a long seismic wave caused a feeling of trepidation for the balance of the night, but not the slightest damage resulted." Earlier in the article the writer referred to the mainshock in San Francisco as "the great earth wave that swept the State of California." The reference to the 16:20 event as "a long seismic wave," therefore, is not construed to imply anything about the type of motion, only that it was long in duration. Report 2: Press and Horticulturist (Riverside), 20 Apr 1906; p. 5, c. 3 "San Jacinto, April 18.-.... There were some who noticed a slight shock here this morning at 5:20, which must have been a part of the great earthquake which did so much damage in San Francisco. Another prolonged, but not hard shock was felt at about 4:15 this afternoon. It lasted several seconds." MMI for this location: IV ? Location Described: Temecula, Riverside Co. Report 1: Lawson (1908), vol. I, p. 413 felt at Temecula MMI for this location: Uncertain Location Described: San Bernardino, San Bernardino Co. Report 1: San Bernardino Daily Sun, 19 Apr 1906; p. 2, c. 6-7 "In San Bernardino yesterday two distinct shocks were felt. The first occurred at 5:15 in the morning, exactly the same moment that it occurred in San Francisco.... The second shock occurred in the afternoon at 4:29, which was quite perceptible to people, especially in the upper floors of two or three story buildings. The clocks in the Santa Fe station were stopped by this shock. Both shocks were very light, however, as compared with disturbances of this sort felt here in the past. Many clocks in residences stopped." Report 2: Lawson (1908), vol. I, p. 300 "... a slight oscillation was felt which caused the chandelier to sway. This movement continued for a few seconds, and seemed to be from northwest to southeast." Report 3: Lawson (1908), vol. I, p. 413 "Southeast." Lawson (1908) estimates Rossi-Forel intensity III. MMI for this location: IV Location Described: Alpine, San Diego Co. Report 1: San Diego Union, 19 Apr 1906; p. 5, c. 1 "... At Alpine the shock was felt with about the same degree of intensity as here [in San Diego]...." MMI for this location: Uncertain Location Described: Ballast Point, San Diego Co. Report 1: Lawson (1908), vol. I, p. 413 "Clock stopt at 4h 28m 15s pend. 18", facing E." Duration 15 seconds. Report 2: Lawson (1908), vol. I, p. 414 "North-south. Horizontal. Clock stopt 4h 30m, facing NW., pend. 17"." Duration: a few seconds. MMI for this location: Uncertain Location Described: Coronado, San Diego Co. Report 1: Los Angeles Examiner, 19 Apr 1906; p. 6, c. 3 "... The shock was also quite severe at Coronado and guests on the top floors of the hotel report their tables, chairs and desks shook considerably...." MMI for this location: IV Location Described: Cuyamaca, San Diego Co. Report 1: San Diego Union, 19 Apr 1906; p. 5, c. 1 "... A telephone message from Cuyamaca stated that the very mountain seemed to rock and that the shock lasted for several seconds...." MMI for this location: Uncertain Location Described: Julian, San Diego Co. Report 1: San Diego Union, 24 Apr 1906; p. 12, c. 2 "Julian, April 23.-.... Despite the fact that this is the last settlement save San Felipe before one comes to the desert, Julian did not feel the slightest shock on the fateful morning of the disaster, yet the desert town of Brawley was severely shaken. In the afternoon, however, a slight tremor was felt, but no damage was done." The writer of this report mistakenly believed that the earthquake which affected Brawley occurred on the morning of the 18th. Regardless, this report establishes that only the afternoon shock was felt in Julian. MMI for this location: IV ? Location Described: Lakeside, San Diego Co. Report 1: San Diegan-Sun, 18 Apr 1906; p. 1, c. 2 "... This report says the shock was quite susceptible [sic] at Lakeside." MMI for this location: Uncertain Location Described: La Mesa, San Diego Co. Report 1: San Diegan-Sun, 18 Apr 1906; p. 1, c. 2 "A shock was felt at La Mesa this afternoon about 4:30. This is probably the same shock which was felt at San Diego...." MMI for this location: Uncertain Location Described: National City, San Diego Co. Several newspapers outside National City reported the earthquake in National City. Some of these reports appear to be based upon one of the reports listed below, and they contain no new information. Only reports with unique information are listed below. Report 1: National City News, 21 Apr 1906; p. 1, c. 2 "Wednesday afternoon at 4:30 o'clock this city experienced two distinct earthquake shocks, followed by a slight tremor. The shocks were strong enough so that everybody felt them. At the home of the editor a large clock on a shelf stopped at half past four to the dot. So far as we have been able to learn no damage was done." Report 2: Diary of Frank A. Kimball (National City, CA), 18 Apr 1906 An excerpt from the page dated WED. APRIL 18, 1906: "A slight earthquake shock at 430 P.M. did no damage." A separate letter written by Frank A. Kimball on 18 April 1906, dated "National City Calif. 4/18, 06," places Kimball in National City on the day of the earthquake. Report 3: Letter of Frank A. Kimball (National City, CA), dated 28 Apr 1906 An excerpt from a letter dated "April 28 [190]6" to A. Snyder Esq., signed by Frank A. Kimball: "The dreadful calamity that befel [sic] San Francisco and adjacent towns was not felt in Southern California-the 'Quake' struck San Francisco at 515 A.M. Wednesday 4/18-but was not felt here-but at 430 P.M. of same day a slight shock was noticed here by a few people. I did not feel it but my wife called my attention to the hanging lamps-suspended from high ceilings by long chains-which were swinging a little. "No disturbance within hundreds of miles and we have no apprehensions of danger from 'Quakes." Report 4: San Diegan-Sun, 18 Apr 1906; p. 1, c. 1-2 "... Three shocks occurred at National City. The first was a heavy one and this was followed by two lighter quakes. Buildings shook, but no damage is reported...." MMI for this location: IV Location Described: Ramona, San Diego Co. Report 1: Lawson (1908), vol. I, p. 413 "A few seconds." Lawson (1908) estimates Rossi-Forel intensity II. MMI for this location: Uncertain Location Described: San Diego, San Diego Co. Many newspapers outside San Diego reported the earthquake in San Diego. Some of these reports appear to be based upon reports that are listed below, and they contain no new information. Only reports with unique information are listed below. Report 1: San Diego Union, 19 Apr 1906; p. 5, c. 1 "As people in this city yesterday afternoon were gathered in groups discussing the terrible catastrophe at San Francisco or were sitting in their offices at their business they were suddenly subjected to an earthquake themselves. To be sure, it was not of any great degree of intensity, and no damage was done to property nor were any persons injured, but it gave San Diegans and tourists, who may be stopping here a taste of the experience with seismic phenomena. The taste was enough for most people, and they will tell of their participation in the great earthquake of 1906-even though they were on the outskirts, so to speak. "An evening paper stated in one of its editions that the shock was the most severe in the history of the city. This, however, is not borne out by the statements of those who experienced former shocks for it was even lighter than some of quite recent years. Chandeliers and hanging lamps were set swaying but not the least damage was done.... "At the office of Weather Observer Ford A. Carpenter, it was reported that the shock came at 4:29:45, and its course was from southwest to northeast. As there is no seismometer here it is difficult to determine the degree of its intensity. Mr. Carpenter would place it as in class No. 4 of the Rossi-Forel scale.... "When the shock was felt here there was a scurrying from office buildings, including the city hall and the court houses. There was no waiting on ceremony, but everybody made for the open with all possible speed, many without hats or coats." The "evening paper" mentioned above is assumed to be the Sun. Compare this report with the articles in the San Diegan-Sun, 18 Apr 1906, p. 1, c. 1-2, and 19 Apr 1906, p. 2, c. 4. In light of comments in the later report (19 Apr) in the Sun, which downplay comments in the Sun's first report, the Sun's reports are not considered fully reliable, and the San Diego Union is believed to have the most reliable account of the earthquake in San Diego. Report 2: San Diegan-Sun, 18 Apr 1906; p. 1, c. 1-2 [UNRELIABLE] "At 4:30 the strongest shock of earthquake known in San Diego in 15 years was experienced. "The direction was from northeast to southwest. "It shook chandeliers, but did no damage, as far as can be reported. Weather Observer Carpenter says: 'The shock, coming from northeast to southwest, is the usual direction, as the records for 15 or 16 quakes show that 75 per cent have come from that direction. No record of anything stronger.' "The weather bureau is in one of the tallest buildings of the city, and the clock there was not stopped. But Mr. Carpenter said that had the direction of the quake been different it would have stopped the clock.... "When the shock came at 4:30 one of the roomers at the Keating block rushed down stairs with all the clothes she could hurriedly gather and fainted after reaching the street. "Telephone communications from different parts of the city say chandeliers swung and tall book cases swayed. This shows that the shock was general all over the city." Compare this with the article in the San Diegan-Sun, 19 Apr 1906, p. 2, c. 4, and with the article in the San Diego Union, 19 Apr 1906, p. 5, c. 1. In light of comments in the later report (19 Apr) in the Sun, which downplay comments in the Sun's first report (above), the Sun's reports are not considered fully reliable, and the San Diego Union is believed to have the most reliable account of the earthquake in San Diego. Report 3: San Diegan-Sun, 19 Apr 1906; p. 2, c. 4 "The following is the official memorandum made by Weather Observer Carpenter of the earthquake felt in San Diego Wednesday afternoon: "'The shock experienced at 4:29:45, S.W. N.E., 20 seconds and was the worst shock experienced in San Diego for the past 15 years.... "'My conclusion as to the severity of the shock Wednesday was based largely upon the visible vibration of two mercurial barometers, each three feet in length, freely suspended in our barometer case. These barometers vibrated to the limit of their fastenings. The sway of the chandeliers and the disturbance of the clock's pendulum were also taken into account in arriving at the conclusion.' "The important fact is not to be forgotten that while Wednesday's shock was the most severe experienced in many years, it was not severe enough to stop a clock." Compare this with the article in the San Diegan-Sun, 18 Apr 1906, p. 1, c. 1-2, and with the article in the San Diego Union, 19 Apr 1906, p. 5, c. 1. In light of comments in the later report (above) in the Sun, which downplay comments in the Sun's first report (18 Apr), the Sun's reports are not considered fully reliable, and the San Diego Union is believed to have the most reliable account of the earthquake in San Diego. Report 4: San Diego Union, 21 Apr 1906; p. 4, c. 1-2 "All rumors that there has been a tidal wave or other disaster here are pure invention. At 4:30 p. m. last Wednesday there was a slight shock of earthquake. It did no damage whatever, and was so light that many people did not feel it." Report 5: San Diego Union, 22 Apr 1906; p. 8, c. 6 "A special dispatch to the Union last evening from the Imperial Standard implied that the damage done at Brawley was not as great as was first reported. By fixing the time, the dispatch shows that the Brawley quake was the one we felt slightly here. The dispatch was: "'Imperial, Calif., April 21.-An earthquake shock on Wednesday at 4:30 p. m. damaged adobes at Brawley. There were no casualties....'" Report 6: Los Angeles Examiner, 19 Apr 1906; p. 6, c. 3 "SAN DIEGO, April 18.-San Diego experienced its first earthquake of the day at 4:28 o'clock this afternoon. The shock was a short one, but was quite pronounced while it lasted. All of the business buildings in the city shook, chandeliers and pictures swayed. The people in the business blocks were greatly frightened and within a few seconds the streets were crowded with agitated men and women. "At the court house the employees were greatly frightened and in less than half a minute the entire building was emptied. This record was equalled by those employed in the city offices at the city hall. "... The shock was apparently felt along the entire western slope of San Diego county. Following the shock many employees of different companies quit work, being unwilling to take chances by remaining at their work in brick buildings. The local weather office reports the course of the quake as being from southwest to northeast." Report 7: Los Angeles Herald, 19 Apr 1906; Part I, p. 4, c. 6-7 "SAN DIEGO, April 18.-While the people were gathered in groups discussing the havoc that has been wrought at San Francisco by earthquakes, at 4:30 o'clock this afternoon a shock was felt here, which threw the town into a state of panic. "Everybody was worked up to a state of nervousness by news from the north and when the shock came people thought that the town was being destroyed. "In a short time the shaking subsided and the town became quiet. No damage was done...." Report 8: Los Angeles Times, 19 Apr 1906; Part II, p. 14, c. 7 "SAN DIEGO, April 18.-[Exclusive Dispatch.] A slight shock was felt here at 4:30 o'clock this afternoon. Many people experienced the feeling of sea sickness. A number of women in buildings fainted, or were rendered unconscious from fright, and were hustled into the open. People rushed out of the larger buildings into the streets. Numerous clocks were stopped and dishes were rattled." Report 9: Los Angeles Times, 20 Apr 1906; Part I, p. 8, c. 5 "SAN DIEGO, April 19.-Telegrams are being received in this city showing that the report has been sent out from Los Angeles that San Diego had suffered damage from earthquake. There has been absolutely no damage done in this section, the only shock felt being a very slight one at 4:30 p.m. yesterday...." Report 10: Lawson (1908), vol. I, p. 413 "Northwest and southeast. Strongest apparently at beginning. Clock not stopt, but disturbed, losing about 1 m.; pend. about 26". No sound phenomena." Duration 20 seconds. Lawson (1908) estimates Rossi-Forel intensity IV-V. Report 11: Lawson (1908), vol. I, p. 413 "Heaviest in 15 years, northeast-southwest." MMI for this location: IV-V (preferred: IV) Location Described: Yuma, Yuma Co., Arizona Report 1: Arizona Sentinel (Yuma), 18 Apr 1906; p. 3, c. 5 "A slight but distinct earthquake was felt here this afternoon at 4:30, lasting perhaps ten seconds. No damage was done, but on account of the reports of the awful destruction at San Francisco the quake caused considerable uneasiness. The direction of the temblor was from northwest to southeast...." Report 2: Riverside Daily Press, 19 Apr 1906; p. 1, c. 2 Press and Horticulturist (Riverside), 20 Apr 1906; p. 1, c. 1 "YUMA, Ariz., April 19.-Yuma experienced nine or ten distinct earthquake shocks at 4:30 p.m. and following the reports of earthquakes elsewhere, caused quite a stir. Tenants of two-story buildings felt it most and rushed out on the streets in haste. No damage resulted." Report 3: Lawson (1908), vol. I, p. 414 "9 or 10 distinct shocks, slight rolling from east to west." Report 4: Townley and Allen (1939), p. 294 "Slight rolling vibration from east to west." This report is attributed to S. Hackett of the U.S. Weather Bureau. MMI for this location: IV-V (preferred: IV) Location Described: Cocopah, Baja California, Mexico Report 1: Richter (1958), p. 485 "... on the afternoon of ... April 18, 1906, there was a strong shock in Imperial Valley, which was then rather thinly settled; nevertheless, there was damage at Brawley, and a water tank was thrown down at the railroad station of Cocopah (Mexico)." According to the National Imagery and Mapping Agency (NIMA) GEOnet Names Server (GNS, available online at http://www.nima.mil/gns/html/), the railroad station of Cocopah also goes by the name Estación Cocopar (or Cocopar) and is located at lat 32° 33' N, lon 115° 14' W. MMI for this location: Uncertain Location Described: Tijuana, Baja California, Mexico Report 1: San Diego Union, 19 Apr 1906; p. 5, c. 1 "... Tia Juana [sic] reported the shock at close to 4:20...." Report 2: Los Angeles Examiner, 19 Apr 1906; p. 6, c. 3 "SAN DIEGO, April 18.-.... Tia Juana [sic] reported that the quake reached there at 4:29 o'clock...." MMI for this location: Uncertain TABLE 7: PRIMARY REPORTS FOR THE 19 APR 1906 TRIGGERED EVENT at 12:31 near SANTA MONICA BAY, CALIFORNIA SEE CORRESPONDING FIGURE 4 Location Described: Avalon, Los Angeles Co. Report 1: Los Angeles Times, 20 Apr 1906; Part II, p. 10, c. 4 "AVALON, April 19.-A slight shock of earthquake was felt here at 12:30 today, but was so slight as to be unnoticed by the majority of people...." Note that, with respect to Avalon and Catalina Island, this report contradicts information given in the Los Angeles Examiner of 20 Apr 1906 (p. 7, c. 7), which states that the earthquake was not felt on Catalina Island. Report 2: Los Angeles Times, 21 Apr 1906; Part II, p. 14, c. 3 "AVALON, April 20.-The uncalled-for rumor of an earthquake here ... caused a great deal of anxiety, as was evidenced by numerous telegrams received from anxious friends and relatives on the mainland. "The canard had the further effect of greatly influencing the travel here, the passenger list today being the lightest of the year, to date. The one little tremor experienced was really too light to be called an earthquake, not more than a dozen people feeling it." Note that, with respect to Avalon and Catalina Island, this report contradicts information given in the Los Angeles Examiner of 20 Apr 1906 (p. 7, c. 7), which states that the earthquake was not felt on Catalina Island. Report 3: Los Angeles Examiner, 20 Apr 1906; p. 7, c. 7 "... Sensation mongers started a foolish report to the effect that Catalina Island had suffered fearfully from the effects of the seismic wave, but reports from the resort stated that the shock had not even been felt there...." Note that, with respect to Avalon and Catalina Island, this report contradicts information given in the Los Angeles Times of 20 Apr 1906 (Part II, p. 10, c. 4) and 21 Apr 1906 (Part II, p. 14, c. 3), which states that the earthquake was felt lightly in Avalon. Report 4: Oregon Daily Journal (Portland), 20 Apr 1906; p. 10, c. 3 "Los Angeles, April 20.-Three slight shocks following in rapid succession shook southern California and startled the visitors at Avalon at noon yesterday. No damage was done and there have been no repetitions of tremors since.... The story that any one was killed at Avalon is absolutely untrue." MMI for this location: III Location Described: Hollywood, Los Angeles Co. Report 1: Los Angeles Examiner, 20 Apr 1906; p. 7, c. 7 "... Hollywood ... felt the shock slightly but no serious damage was caused...." Report 2: Los Angeles Examiner, 20 Apr 1906; p. 7, c. 7 "... Hollywood also felt the tremor shortly after noon yesterday. A slight crack in a wall of a building was the full extent of the damage...." MMI for this location: IV-V (preferred: IV) Location Described: Long Beach, Los Angeles Co. Report 1: Long Beach Evening Tribune, 19 Apr 1906; p. 4, c. 5-6 "A slight tremor was noticed in Long Beach at 12:28 today, and timid ones, ready to jump at the dropping of a pin, avowed it was a quake and then looked over to the east to see if 'Old Baldy' was smoking. The shock, if it was such, was noticed only within doors. Outside it was not felt." Report 2: Los Angeles Times, 20 Apr 1906; Part II, p. 14, c. 1 "LONG BEACH, April 19.-This city was visited by an earthquake shock at 12:28 o'clock this afternoon. The shock was of three or four seconds' duration, and was from north to south and seemed to be stronger north of town. Windows and doors rattled, but no damage is reported beyond the tension on the nerves of people already on a hair-trigger strain. All the city schools were dismissed at noon today because the children were too restless and unstrung to do any studying." Report 3: Los Angeles Examiner, 20 Apr 1906; p. 7, c. 7 "... Long Beach ... felt the shock slightly but no serious damage was caused...." MMI for this location: IV Location Described: Los Angeles, Los Angeles Co. Report 1: Los Angeles Examiner, 20 Apr 1906; p. 7, c. 7 "Los Angeles and surrounding towns experienced a slight earthquake shock at 12:31 o'clock yesterday afternoon, but no damage whatever was caused by the disturbance. "The temblor came at a time when the downstairs cafes, hotels and office buildings were filled with people, but beyond causing momentary fright to nervously inclined persons, the shock had no effect whatever. "The exact time of the quake was 12:31:40 p. m., as recorded by Observer Franklin of the United States Weather Bureau. It lasted only about three seconds, though many excited individuals thought it lasted much longer.... "'It amounted to absolutely nothing,' said Mr. Franklin. 'My office boy, who was keenly alert, noticed it, but thought someone had simply slammed a door.' "Rumors were current that many of the big buildings had settled and that cracks had appeared in the Conservative Life, city jail and other buildings, but these were proved by investigation to be absolutely untrue. "A crack in one of the stones in the jail building was noticed by some for the first time, although it had been there for nearly ten years. Neither the Conservative Life nor any of the other buildings in the city was affected in the least. "When the temblor was felt, the timid rushed from the big buildings and in several of the cafes where noonday lunchers were dining, several made the earthquake scare an excuse to get out in a hurry. "At the various beach resorts the shock was felt and the incoming cars were soon crowded by people who were frightened by predictions of a tidal wave. The ocean was perfectly serene and no cause whatever for the excitement could be found...." Report 2: Los Angeles Examiner, 20 Apr 1906; p. 6, c. 2 "Los Angelenos have determined not to be discomfited by any little temblor that comes along. "Yesterday afternoon at the Jonathan Club there were a hundred or more men about town playing dominoes and loafing about waiting for the general lunch hour. "It was at this time that the little temblor came along and gave the Huntington building a shake that set the chandeliers to swinging. "The men playing dominoes simply looked up for a minute and continued their game. "Walter Parker and Phil Stanton were playing a game.... "Just as the tremblor swung the building, Stanton became impatient, and said: 'It's your play, Walter; get a move on.' "'It seems to me,' replied Parker, looking up at the dancing chandeliers and gripping the arms of his chair, 'that I am moving.'" Report 3: Los Angeles Express, 19 Apr 1906; p. 3, c. 3-4 "Attempts not only to make the East believe that Los Angeles is seriously affected by the earthquake shocks, but to create fear here, have come to light through investigation of an absurd message sent to the war department by some irresponsible person in San Francisco.... "The fake came to light in a message to Los Angeles as follows: "'WASHINGTON, April 19.-The war department has received the following telegram from San Francisco: 'Los Angeles says building rocking like a boat. Just lost connection with Los Angeles immediately after this report. Men probably left building.'' "While there was a tremor of the earth's surface in Los Angeles, it was so slight as to be barely noticeable, except in the tallest buildings, and at the United States weather observatory it was classed as nothing unusual. "A few persons asserted that they had felt the shock, but until the news from the North came many thought that any temblor which they might have believed themselves to have experienced was more the effect of an overwrought imagination and nervousness caused by the disaster in San Francisco. "G. E. Franklin, at the head of the United States weather bureau, in his report of the quake ten minutes after it had occurred, said: "'There was nothing at all unusual in the shock. I timed it as happening at 12:31 1/4 o'clock. It was of hardly sufficient strength to move the pendulum of the large clock in my office, and of a single undulation, seemed to be moving from north to south....'" Report 4: Diary of Selena Gray Ingram (Los Angeles, CA), 19 Apr 1906 Written in the top margin of the page for the 19 Apr 1906 entry: "We had a shock in Los Angeles today at noon-but no damage was done." Report 5: Lawson (1908), vol. I, p. 414 "Increased intensity, 1 max., strongest at middle. No sound." Duration 20-30 seconds. Time listed for this event is 12:31:00. Report 6: Lawson (1908), vol. I, p. 414 Felt at Los Angeles. Time listed for this event is 12:31:41. Report 7: Lawson (1908), vol. I, p. 415 "Two shocks about 6 m. apart followed by slight tremors for about 1 h." Time listed for this event is 12:33. Report 8: Riverside Daily Press, 19 Apr 1906; p. 8, c. 3 "LOS ANGELES, April 19.-(Special to Press.)-Los Angeles was thrown into a tremor of fright at 12:31 today by two sharp and distinct earthquake shocks. These lasted but a few seconds and did no appreciable damage, but the feelings of the people were at such a high pitch that they became panicky and rushed out of doors at the first tremor. Although the shocks were light, the feeling was so intense that a large number refused to return to brick buildings again and sought the parks to spend the remainder of the afternoon." Report 9: Oregon Daily Journal (Portland), 20 Apr 1906; p. 10, c. 3 "... it was so slight that that many people did not notice it, and no damage was done in any way." Report 10: The Independent (Santa Barbara), 19 Apr 1906; p. 1, c. 1-3 [UNRELIABLE] "LOS ANGELES, April 19.-... a distinct earthquake shock was felt throughout this city. The seismic disturbance was sufficient to make the large buildings in the down town districts tremble perceptibly, in several parts of the city chimneys were thrown down and other minor damage done. This coming at a time when the public mind is so wrought up over the fearful results of the earthquake in San Francisco immediately created the utmost consternation, almost amounting to a panic. Men turned pale and women became hysterical. Many of the occupants of the large public buildings sought the streets, but the commotion quickly subsided, though the feeling of nervousness remained. Out in the residence portion of the city, however, women and children fled from their homes into the streets and many of them have refused to return. The shock has been sufficient to create a general panicky feeling." In comparison to reports published in local newspapers, this account is obviously exaggerated. Report 11: San Diegan-Sun, 19 Apr 1906; p. 1, c. 6-7 [UNRELIABLE] "Shortly after noon Thursday the report was confirmed at the Western Union telegraph office that Los Angeles had experienced an earthquake shock at 12:50 p. m. today. "No damage was done, but the shock was sharp. "Employees of the Western Union Telegraph company in Los Angeles, it is stated, deserted their work, but later returned. "For a time all communication with Los Angeles was cut off. "Bensel Smythe, the Sun's special representative at Los Angeles, 'phoned the Sun at 1:25 p. m. that the earthquake was felt only in the business part of the city. "An elevator in the Bryson building was left suspended between the second and third floors and was still there full of people at the hour of receipt of the message. "The Bryson building is located at Second and Spring streets.... "The report reached San Diego that Los Angeles has had a second shock today." In comparison to reports published in local newspapers, this account is obviously exaggerated. MMI for this location: IV Location Described: Monrovia, Los Angeles Co. Report 1: Los Angeles Examiner, 20 Apr 1906; p. 7, c. 7 "... Monrovia ... felt the shock slightly but no serious damage was caused...." MMI for this location: Uncertain Location Described: Ocean Park, Los Angeles Co. Report 1: Los Angeles Examiner, 20 Apr 1906; p. 7, c. 7 "... At Ocean Park guests of the Hotel Decatur fled from the buildings and the streets were soon thronged with residents, many of them carrying personal effects. Their fears were soon allayed and the majority of them returned to their homes...." MMI for this location: V ? Location Described: Pasadena, Los Angeles Co. Report 1: Los Angeles Examiner, 20 Apr 1906; p. 7, c. 7 "... Pasadena ... felt the shock slightly but no serious damage was caused...." MMI for this location: Uncertain Location Described: San Pedro, Los Angeles Co. Report 1: Los Angeles Times, 20 Apr 1906; Part II, p. 14, c. 2 "SAN PEDRO, April 19.-.... At exactly 12:30 o'clock today there was an earthquake shock felt here that was sufficient to cause a jarring and shaking up of the buildings, creating considerable excitement in the downtown district, but doing no damage. "People in all the business houses rushed into the streets and for a time there was some alarm. It was all over in a moment, however, and all uneasiness soon passed away. "Several slight cracks in buildings were reported; glass bottles were thrown from the shelves in the drug stores and dishes in the restaurants rattled greatly. No damage at all was reported. People living in the resident district felt it slightly, but not so great as downtown. "It was sufficient to knock the plaster off the tower of the town clock and loosen considerable earth on Knob Hill." Report 2: Los Angeles Examiner, 20 Apr 1906; p. 7, c. 7 "... San Pedro ... felt the shock slightly but no serious damage was caused...." Report 3: Lawson (1908), vol. I, p. 415 "Horizontal tremors 10 s. before, increased intensity, strongest at end. No sound." Duration 15 seconds. MMI for this location: V Location Described: Santa Monica, Los Angeles Co. Report 1: Daily Outlook (Santa Monica), 19 Apr 1906; p. 1, c. 4 "At 12:29 today the Santa Monica bay section heard the awful rumble and roar and felt the vibrations and undulations of an earthquake shock. The tremblor moved from north to south, apparently quite closely following the coast line. The disturbance had a duration of thirty-two seconds and during that time there was a perceptible swaying of buildings and creaking and crackling of timbers. "A slight crack under the window of the Joseph Kuhrts building at the door of the Kuhrts building [sic] at the corner of Utah and Second was observed...." Report 2: Los Angeles Times, 20 Apr 1906; Part II, p. 14, c. 2 "SANTA MONICA, April 19.-At 12:20 today Santa Monica felt, with distinctness that carried alarm with it, the undulations of an earthquake shock. There were apparently three separate shakes, all moving from north to south and lasting thirty-two seconds...." MMI for this location: IV-V (preferred: V) Location Described: Sawtelle, Los Angeles Co. Report 1: Los Angeles Times, 20 Apr 1906; Part II, p. 14, c. 2 "SAWTELLE, April 19.-This community received a severe shaking up at 12:30 o'clock today. To all appearances the movement of the temblor was from north to south. So decided were the vibrations that canned goods on the shelves in grocery stores were shaken to the floor with a crash. Mirrors in barber shops were broken. People ran out of their houses in alarm, their faces depicting terror, but there was no damage to any of the buildings in the city." Report 2: Los Angeles Examiner, 20 Apr 1906; p. 7, c. 7 "... At Sawtelle it was reported that canned goods and other articles were shaken from the shelves of stores, but this rumor was found to be greatly exaggerated. People rushed into the streets and an old soldier was knocked from his crutches, but was not injured...." MMI for this location: V Location Described: Soldiers Home, Los Angeles Co. (now Veterans Administration land, west of Westwood) Report 1: Los Angeles Times, 20 Apr 1906; Part II, p. 14, c. 2 "SOLDIERS' HOME, April 19.-The earthquake here half an hour after noon today was severe in the barracks. Many of the veterans rushed out of the buildings. Local Manager H. H. Markham, who is visiting here, said he was startled by the shock...." MMI for this location: V ? Location Described: Venice, Los Angeles Co. Report 1: Los Angeles Examiner, 20 Apr 1906; p. 7, c. 7 "... At Venice bits of plastering fell from the walls of several buildings and a high chimney was slightly cracked, but no damage of any consequence occurred...." Report 2: Los Angeles Times, 20 Apr 1906; Part II, p. 14, c. 2 "SANTA MONICA, April 19.-.... Except for a few minor cracks in the taller of the brick buildings at Venice the quake left no scars." Report 3: Daily Outlook (Santa Monica), 19 Apr 1906; p. 1, c. 4 "... At Venice several of the tall brick buildings were cracked just a little." MMI for this location: VI Location Described: Whittier, Los Angeles Co. Report 1: Los Angeles Examiner, 20 Apr 1906; p. 7, c. 7 "... Whittier ... felt the shock slightly but no serious damage was caused...." MMI for this location: Uncertain Location Described: Santa Ana, Orange Co. Report 1: Evening Blade (Santa Ana), 19 Apr 1906; p. 8, c. 3 "Another slight shock of earthquake was felt today at Santa Ana at 12:30, the tremor being sufficient to sway the chandeliers in the various rooms of the county court house and jar the whole building from foundation to cupola. The vibrations were from northeast to southwest and lasted for several seconds." Report 2: Los Angeles Examiner, 20 Apr 1906; p. 7, c. 7 "... A slight shock at 12:30 o'clock yesterday is reported from Santa Ana. No damage was done...." MMI for this location: III-IV (preferred: IV) Location Described: Riverside, Riverside Co. Report 1: Riverside Daily Press, 19 Apr 1906; p. 8, c. 3 "Riverside also experienced a tiny shiver at 12:30, not large enough to be felt by the majority, but still perceptible in tall buildings." Report 2: Los Angeles Times, 20 Apr 1906; Part II, p. 14, c. 3 "RIVERSIDE, April 19.-.... At 12:30 o'clock today there was a slight shake here of the same character as the tremor of yesterday." MMI for this location: III Location Described: Ontario, San Bernardino Co. Report 1: Los Angeles Examiner, 20 Apr 1906; p. 7, c. 7 "... At Ontario the shocks of the earthquake were so slight as to pass unnoticed by most of the residents...." MMI for this location: III Location Described: San Bernardino, San Bernardino Co. Report 1: Los Angeles Times, 20 Apr 1906; Part II, p. 14, c. 3 "SAN BERNARDINO, April 19.-.... A slight shock was perceptible here at 1:15 o'clock this afternoon." MMI for this location: III Location Described: Ventura, Ventura Co. Report 1: Daily Free Press (Ventura), 19 Apr 1906; p. 2, c. 1 "Another slight tremor was felt here at 12:35 today. The shake was slight but it was very noticeable and set all hanging articles in motion. The shake had a tendency to cause much alarm in the city, fearing that it might be worse in other places than it was here. No damage has been reported as a result of today's shake." MMI for this location: IV TABLE 8: PRIMARY REPORTS FOR THE 19 APR 1906 TRIGGERED EVENT at 20:15 near FERNLEY, LYON COUNTY, NEVADA SEE CORRESPONDING FIGURE 5 Location Described: Carson Dam, Churchill Co., Nevada Report 1: Lawson (1908), vol. I, p. 324-325 "... It was apparently not felt at Fallon, tho it was distinctly felt 12 miles west at Carson Dam...." Report 2: Townley and Allen (1939), p. 280 "Carson Dam. Twelve miles west of Fallon; shock plainly felt." MMI for this location: Uncertain Location Described: Fallon, Churchill Co., Nevada Report 1: Lawson (1908), vol. I, p. 324-325 "... It was apparently not felt at Fallon...." Report 2: Townley and Allen (1939), p. 280 "Not felt at Reno, Fallon, Lovelock, and east." MMI for this location: Not Felt Location Described: Hazen, Churchill Co., Nevada Report 1: Lawson (1908), vol. I, p. 324-325 "... It was generally felt at Hazen, Wadsworth, Olinghouse, and neighboring places where it is hard to find any one that noticed any effects of the great quake. In Hazen it rattled windows, made gas jets and lamps swing, and doors swing on hinges. The railroad station clock is said to have stopt.... The vibration was apparently northwest-southeast, or north-south, at Hazen...." Report 2: Townley and Allen (1939), p. 280 "Windows rattled; gas jets swung north to south." MMI for this location: IV-V Location Described: Fernley, Lyon Co., Nevada Report 1: Lawson (1908), vol. I, p. 324-325 "... In the Reclamation Service camp at Fernley it was quite strong, as felt on the ground in the tent.... At Fernley ... it was described as northeast-southwest." Report 2: Townley and Allen (1939), p. 280 "Quite strong in tent.-Mr. Post at Reclamation Service Camp." MMI for this location: V Location Described: Browns Station, Pershing Co., Nevada Report 1: Lawson (1908), vol. I, p. 324-325 "... It was felt as far east as Brown's Station...."* Report 2: Townley and Allen (1939), p. 280 "Men preparing for bed scared and ran out of house." * Carlson (1974) identifies two locations named "Browns Station," both of which would be on the periphery of the felt region for this event. One of them-the earliest station of this name-was located on the Carson River "about three miles above old Fort Churchill" in Lyon County. This would be south and west of most of the other points of observation. The other Browns Station -according to Carlson-was in Churchill County, 16 miles southwest of Lovelock, and was "a famous point on the Overland Stage route and later on the Southern Pacific Railroad." [While approximately correct, Carlson placed the location in the wrong county. The USGS Geographic Names Information System (GNIS, available online at http://geonames.usgs.gov/) locates this point precisely along the old route of the Central Pacific Railroad, 0.3 miles west of the present-day locality of Toy, in present-day Pershing County. Toy is on the Toulon, Nev., 15' quadrangle topo map of 1956.] The latter location for Browns Station would be north and east of the other points of observation. This would also be at about the same longitude, but north of, Fallon, where it was not felt. The latter location seems more plausible, in light of the statement that it was felt "as far east as" Browns Station and in light of the implication that the Pershing County location was more well known. [In addition, the USGS GNIS lists the Browns Station in Pershing County as a "populated place," whereas the Browns Station in Lyon County is only a "locale."] MMI for this location: IV ? Location Described: Lovelock, Pershing Co., Nevada Report 1: Townley and Allen (1939), p. 280 "Not felt at Reno, Fallon, Lovelock, and east." MMI for this location: Not Felt Location Described: Olinghouse, Washoe Co., Nevada Report 1: Lawson (1908), vol. I, p. 324-325 "... It was generally felt at Hazen, Wadsworth, Olinghouse, and neighboring places where it is hard to find any one that noticed any effects of the great quake.... At Olinghouse also it was felt as a sharp shock-one called it a quiver-and caused windows to rattle...." Report 2: Townley and Allen (1939), p. 280 "Windows rattled; crowd in hotel bar-room scared and ran outside." MMI for this location: IV Location Described: Reno, Washoe Co., Nevada Report 1: Townley and Allen (1939), p. 280 "Not felt at Reno, Fallon, Lovelock, and east." MMI for this location: Not Felt Location Described: Steamboat Springs, Washoe Co., Nevada Report 1: Lawson (1908), vol. I, p. 325 "... A second shock, seemingly as hard as the first, was felt the second or third night after [the California mainshock]." The date and time of the event described cannot be resolved. MMI for this location: Uncertain [may have been a different event] Location Described: Wadsworth, Washoe Co., Nevada Report 1: Lawson (1908), vol. I, p. 324-325 "... It was generally felt at Hazen, Wadsworth, Olinghouse, and neighboring places where it is hard to find any one that noticed any effects of the great quake.... At Wadsworth, it made the windows rattle and caused some fear, owing to reports of the San Francisco disaster. One person describes it as a quick sharp shock like a blast...." Report 2: Townley and Allen (1939), p. 280 "Sharp, quick shock like a blast; windows rattled." MMI for this location: IV Location Described: East slope of the Virginia Range, Nevada Report 1: Lawson (1908), vol. I, p. 324-325 "The Earthquake of April 19, 1906, 8h 15m to 8h 30m P. M. (Intensity, IV-V.)-This earthquake was distinctly felt along the east slope of the Virginia range and the valley land directly east and not far north or south of Lat. 39° 31'. Wherever reported it was much stronger than the shake produced by the California earthquake of the previous day...." Report 2: Lawson (1908), vol. I, p. 415 "On east slope of Virginia Range, Sierra Nevadas; northwest-southeast. During next 1.5 h. 3 more." Lawson (1908) estimates Rossi-Forel intensity IV-V for the shock at 20:15-20:30. This report is attributed to "G. D. L." There is a key to people's initials following the list of aftershocks in Lawson (1908), but "G. D. L." is not included in the key. The report in Townley and Allen (1939) for the same earthquake credits George D. Louderback of the University of Nevada, Reno, and indeed, G. D. Louderback was a co-author of Lawson (1908), making the reference obvious. MMI for this location: Uncertain TABLE 9: PRIMARY REPORTS FOR THE 23 APR 1906, 01:10 AFTERSHOCK SEE CORRESPONDING FIGURE 6 Location Described: Oakland, Alameda Co. Report 1: Courier-Free Press (Redding), 23 Apr 1906; p. 1, c. 2 [UNRELIABLE] "The shake was felt as far north as Portland and Seattle and south in Oakland and San Francisco, though no damage was reported from any section in the state." These statements must be erroneous. The report is not corroborated in either the Oregon Daily Journal or the Morning Oregonian, both of which were published daily in Portland. Also, there are no reliable reports which suggest that this earthquake was felt in Oakland, San Francisco, or Seattle. MMI for this location: Unreliable Location Described: Chico, Butte Co. Report 1: Chico Semi-Weekly Record, 24 Apr 1906; p. 1, c. 6 "The shock was felt by several in Chico, but was not of sufficient severity to awaken more than a few in the town." MMI for this location: III Location Described: Crescent City, Del Norte Co. Report 1: Del Norte Record, 28 Apr 1906; p. 3, c. 2 "... another earthquake shock was felt here. Some who were awakened reported that the shock was more severe than that on the morning of the 18th inst. The western and eastern portions of town received the heaviest shock. No damage was done...." Report 2: Humboldt Times, 24 Apr 1906; p. 8, c. 4 [UNRELIABLE] "As nearly as can be learned the recent shake extended farther north than did the other, and it is reported that Arcata and the towns in the northern part of the county felt the thrill, and that Crescent City and Grants Pass got it stronger than ever before...." Report 3: Oregon Daily Journal (Portland), 23 Apr 1906; p. 9, c. 6 [UNRELIABLE] "Telephone reports from Crescent City, California, state that that place was severely shaken last night, as was Sisson and other northern California towns." Report 4: Lawson (1908), vol. I, p. 416 "... Woke up everybody, no damage." MMI for this location: IV ? Location Described: Georgetown, El Dorado Co. Report 1: Georgetown Gazette, 4 May 1906; p. 3, c. 1 "An earthquake shock was felt here shortly after one o'clock Monday morning. No damage done." Although the article implies that the "Monday morning" to which it refers was the Monday of that week, i.e., 30 Apr, it is also possible that it was the previous Monday, 23 Apr. The lack of corroborating reports from nearby localities for 30 Apr, and the existence of a felt report from Grass Valley (to the north) for an event at about 01:15 on the morning of 23 Apr, suggest that this may be the 23 Apr event. MMI for this location: Uncertain [may have been a different event] Location Described: Arcata, Humboldt Co. Report 1: Humboldt Times, 24 Apr 1906; p. 7, c. 6-7 "ARCATA, April 23.-.... Another earthquake shock was felt here this morning at about 3 o'clock. Although not as violent as the first one, it caused a little damage and aroused people in some instances from their houses." Report 2: Humboldt Times, 24 Apr 1906; p. 8, c. 4 "As nearly as can be learned the recent shake extended farther north than did the other, and it is reported that Arcata and the towns in the northern part of the county felt the thrill, and that Crescent City and Grants Pass got it stronger than ever before...." MMI for this location: V Location Described: Blocksburg, Humboldt Co. Report 1: Humboldt Standard, 26 Apr 1906; p. 6, c. 1 "a double sharp shake with distinct rumblings" MMI for this location: Uncertain Location Described: Cape Mendocino, Humboldt Co. Report 1: Lighthouse Log for Cape Mendocino Lighthouse, 23 Apr 1906 "shock of earthquake 0:55 a.m. and started stopped clock in tower woke up everybode [sic] and rushing out of hous [sic] but no damage was done the shock traveled from South to North." This report describes an earthquake at 00:55 on 23 Apr; another earthquake was felt at 01:17. Report 2: Lawson (1908), vol. I, p. 416 "Vertical. Southwest-northeast. Direction NE. increasing intensity. Clock stopt. Pend. 22", facing SW. No sound." Duration 6 seconds. This report describes an earthquake at 00:55 on 23 Apr; another earthquake was felt at 01:17. These reports are probably not independent of the Cape Mendocino lighthouse logs. Report 3: Humboldt Times, 29 Apr 1906; p. 5, c. 2 [UNRELIABLE] "Information was received over the telephone at this office last evening to the effect that the earthquake which occurred last Monday morning, demolished the keeper's house at the Cape Mendocino light-house. The stone tower which contains the light was not damaged and neither was any of the other buildings." This report appears to be incorrect. The lighthouse log, kept by the lighthouse keeper at Cape Mendocino, states that no damage was done at Cape Mendocino by this earthquake. The lighthouse log is considered more reliable, since it is a first-hand account. MMI for this location: V Location Described: Eureka, Humboldt Co. Report 1: Humboldt Standard, 23 Apr 1906; p. 5, c. 5-6 "Ever since the disastrous quake at 5:11 a. m. Wednesday [April 18], there have been innumerable shocks of more or less severity at intervals but none approaching the severity of the first. One o[f] the heaviest of these occurred at 1:10 o'clock this morning and caused considerable consternation among the people owing to the length of time that the vibrations continued. In fact the period was fully as long as that of the first shake of Wednesday. However, besides rattling things about considerably, spilling liquids from open dishes, and stopping clocks, as far as learned there was no serious damage done about the city. The only exciting incident appears to have been the breaking of a live electric wire in front of the Daly Bros. store at Fourth and F streets. This did no damage however." Report 2: Humboldt Times, 24 Apr 1906; p. 8, c. 4 "As compared with the shock of last Wednesday morning, the quakes felt here yesterday morning did little or no damage. A window pane here and there which had been cracked from the big temblor fell out, a few bricks which had become loosened on a number of chimneys about town tumbled down, putting the fear of the Almighty in the hearts of many, and the houses generally were shaken up, sufficiently to awaken the populace. There were many who remained awake the remainder of the night and few of the more timid who sought the streets.... "Locally [in Eureka] there were two shocks. The first was at 1:10 a. m. , with vibrations from south to north and lasting 14 seconds. The second was exactly at 6:07 a. m. ... lasting four seconds." From the wording, it appears that the first paragraph is mostly about the 01:10 shock and not the 06:07 shock; from this account, and from others in Eureka and southern Humboldt County, it appears that the 06:07 shock was significantly less intense in that area than the 01:10 shock. Report 3: Courier-Free Press (Redding), 23 Apr 1906; p. 1, c. 2 [UNRELIABLE] "slight ... no damage was done" Report 4: Lawson (1908), vol. I, p. 416 "South-north. Stopt clocks." Duration 14 seconds. Lawson (1908) estimates Rossi-Forel intensity V-VI. MMI for this location: V Location Described: Ferndale, Humboldt Co. Report 1: Humboldt Standard, 23 Apr 1906; p. 5, c. 5-6 "Telephonic communication with Ferndale was partially restored late this forenoon, when it was learned that the shock this morning did little or no damage there. A few more bricks were knocked out of the walls of the Russ, Early & Williams wrecked brick store, a few movable articles about town were disturbed, and that was about all." Report 2: Humboldt Times, 24 Apr 1906; p. 8, c. 4 "The shock was felt at Ferndale, but comparatively no damage was done. In fact it was felt by all the valley towns about the same as in Eureka...." Report 3: Lawson (1908), vol. I, p. 416 "Severe shock." Duration 10 seconds. MMI for this location: V Location Described: Fieldbrook, Humboldt Co. Report 1: Arcata Union, 28 Apr 1906; p. 8, c. 3 "People were awakened from their sleep ... by another earthquake." The time of the event is not given in this report, except that it occurred in the morning. MMI for this location: Uncertain Location Described: Hydesville, Humboldt Co. Report 1: Humboldt Standard, 23 Apr 1906; p. 5, c. 5-6 "The telephone wire was working spasmodically as far as Hydesville, and from there it was learned that no damage was done by this morning's earthquake." MMI for this location: Uncertain Location Described: Orick, Humboldt Co. Report 1: Arcata Union, 28 Apr 1906; p. 8, c. 3 "Orick. / April 23, 1906. / This vicinity was visited by an earthquake Wednesday morning [18 Apr] at 5:20 a. m. This morning at 1 o'clock there was another fully as heavy as the first and at half past five another, fully as heavy as any preceding. All the damage done was to break a few panes of glass." It is not clear which of the earthquakes mentioned were responsible for breaking the panes of glass. MMI for this location: V Location Described: Trinidad Head, Humboldt Co. Report 1: Lawson (1908), vol. I, p. 416 "East-west tremor 5 s. before, short and heavy; clock stopt 12h 48m a. m., facing east; sound like thunder, preceded and continued during shock; same throughout, no change." Duration 8 seconds. MMI for this location: Uncertain Location Described: between Alton and Fortuna (?), Humboldt Co. Report 1: Humboldt Standard, 23 Apr 1906; p. 5, c. 5-6 "One effect of the earthquake shock of early this morning was to cause a slide to come in on the Scotia road, which prevented the train from coming in from there with the overland mail this morning and delayed the arrival of the train from Alton about one hour." What was called the Scotia road probably ran from Fortuna to the south, through Scotia. Because the slide blocked the trains from both Scotia and Alton, the slide must have occurred north of Alton, which is between Scotia and Fortuna. Hence the slide most likely occurred between Alton and Fortuna. For several hundred meters north of Alton, the road and railroad tracks run along the base of an escarpment, and this seems to be the most likely location of the slide. MMI for this location: Uncertain Location Described: San Rafael, Marin Co. Report 1: Marin Journal, 26 Apr 1906; p. 5, c. 3 "A slight earthquake shock was felt here at about 1 o'clock Monday night. It was of short duration and no damage." It is not clear whether "about 1 o'clock Monday night" refers to the early morning of 23 or 24 Apr. MMI for this location: Uncertain [may have been a different event] Location Described: Point Arena Lighthouse, Mendocino Co. Report 1: Lighthouse Log for Point Arena Lighthouse, 22 Apr 1906 "At 1130 p.m. slight jar in tower." Although the timing is a little off, this is inferred to be the event of the early morning of 23 Apr. Even if it is not the same event as the earthquake felt across much of northern California on 23 Apr, this entry in the lighthouse log still provides some constraints: if the lighthouse keeper would bother to note a "slight" earthquake in his log, but he did not note a different earthquake about two hours later, the later earthquake (i.e., the event felt across much of northern California) must not have been strong enough to wake him. If that is the case, the later event probably did not have an intensity (MMI) greater than IV. MMI for this location: III ? Location Described: Grass Valley, Nevada Co. Report 1: Daily Morning Union (Grass Valley and Nevada City), 24 Apr 1906; p. 2, c. 5 "Some watches caught it at 1:15 and some at 1:16 yesterday morning. The shock was sufficient to set two-story dwellings a-quiver, but did not possess strength enough to rattle doors and windows and shake people up as did the shocks last Wednesday. The course of the quake seemed to be about the same as that of last week, from southeast to northwest. Only light sleepers were awakened, but the few who chanced to be up at that hour give a dependable account of the shock, which lasted fully fifteen seconds." MMI for this location: III Location Described: La Porte, Plumas Co. Report 1: Plumas National-Bulletin, 23 Apr 1906; p. 1, c. 5 "Several of our citizens [in Quincy] emphatically declare that there was a pronounced earthquake shock last night at about 1 a. m. Rumors to the same effect come over the telephone line from the La Porte way, but we are unable to secure telephone communication with lower country points to confirm or deny the rumor...." MMI for this location: III Location Described: Quincy, Plumas Co. Report 1: Plumas National-Bulletin, 23 Apr 1906; p. 1, c. 5 "Several of our citizens [in Quincy] emphatically declare that there was a pronounced earthquake shock last night at about 1 a. m. Rumors to the same effect come over the telephone line from the La Porte way, but we are unable to secure telephone communication with lower country points to confirm or deny the rumor...." MMI for this location: III Location Described: Sacramento, Sacramento Co. Report 1: The Searchlight (Redding), 24 Apr 1906; p. 1, c. 1-2 [UNRELIABLE] "a slight tremor of the earth" This report is not corroborated in any of the Sacramento newspapers. Report 2: Humboldt Standard, 23 Apr 1906; p. 1, c. 4-5 [UNRELIABLE] "A very slight shock was felt in Sacramento." The time of the event is not given in this report, except that it occurred in the morning. This report is not corroborated in any of the Sacramento newspapers. MMI for this location: Unreliable Location Described: San Francisco, San Francisco Co. Report 1: Courier-Free Press (Redding), 23 Apr 1906; p. 1, c. 2 [UNRELIABLE] "The shake was felt as far north as Portland and Seattle and south in Oakland and San Francisco, though no damage was reported from any section in the state." These statements must be erroneous. The report is not corroborated in either the Oregon Daily Journal or the Morning Oregonian, both of which were published daily in Portland. Also, there are no reliable reports which suggest that this earthquake was felt in Oakland, San Francisco, or Seattle. Report 2: Del Norte Record, 28 Apr 1906; p. 3, c. 2 [UNRELIABLE] "... The shock was felt in Grants Pass, but not in San Francisco." It is not clear where the report about the earthquake being unfelt in San Francisco originated from, and considering that no sources in San Francisco either confirmed or denied feeling this earthquake, the statement in the Del Norte Record should not be fully trusted. Note that it conflicts with the statement in the Courier-Free Press (Redding), above. MMI for this location: Unreliable Location Described: Stockton, San Joaquin Co. Report 1: The Searchlight (Redding), 24 Apr 1906; p. 1, c. 1-2 [UNRELIABLE] "For a period of perhaps six seconds the earth quivered slightly.... Only people of nervous, restless temperament were awakened by the tremor." This report is not corroborated in any of the Stockton newspapers. MMI for this location: Unreliable Location Described: Kennett, Shasta Co. Report 1: The Searchlight (Redding), 25 Apr 1906; p. 3, c. 3 "The earthquake at 1 o'clock Monday morning was felt by everybody working on night shift in the smelter." MMI for this location: Uncertain Location Described: Redding, Shasta Co. Report 1: The Searchlight (Redding), 24 Apr 1906; p. 1, c. 1-2 "Two distinct shocks of earthquake shook up Redding at 1:10 o'clock Monday morning. The second shock, which was much the sharper, came about ten seconds after the first. The total duration of the seismic disturbance is variously estimated at from ten to twenty seconds. "Guests in the Lorenz, Golden Eagle and Temple hotels were alarmed and a few came down into the office or out into the street, dressed only in their night clothing. The electric clock in the Temple Hotel stopped at 1:10 a. m. No other electric clocks in town were affected. "The quake awakened people throughout Redding, but hundreds and hundreds of sleepers were not disturbed at all and first learned of the earthquake when they arose for the day. "As compared with the shake-up of last Wednesday morning, the earthquake of yesterday morning is described by some as being sharper, while others insist that it was not so sharp. Perhaps the happy mean is about the correct estimate and Monday's quiver was only a duplicate of that of last Wednesday. "H. Bemis, who sleeps in the Gem Lodging-house, says he was awakened by a jerking motion of his bed. The jerking ceased momentarily, but for a few seconds-perhaps eight or ten-the bed continued to tremble a little, and then came the last and final jerking, much sharper than the shake-up that had awakened him. With that the event was over. During the earthquake he could hear a tapping on the windows, perhaps caused by the rattling of the panes. An open door somewhere in the house swung on its hinges, grinding out a noise something like 'hee-haw, hee-haw!'" Report 2: Courier-Free Press (Redding), 23 Apr 1906; p. 1, c. 2 "The people of Redding experienced another earthquake shock at 1:20 o'clock Monday morning. In some sections of town the twister was felt more plainly than in others. Many people slept through it all, not knowing of any disturbance until they awakened and were told of the affair by their neighbors, whose slumbers had been disturbed. "The shock was accompanied by a rumbling noise similar to that made by a locomotive. Many who felt the shock did not consider it of sufficient import to get out of bed, while others made hasty exits from their lodgings. "Several guests at the Lorenz and Golden Eagle hotels were awakened but none were badly frightened. "A stone and concrete fence on the north Liberty street premises of A. J. Martin ... was cracked in several places. Note that "twister" is used in this article as a reference to the earthquake. Report 3: Chico Semi-Weekly Record, 24 Apr 1906; p. 1, c. 6 "REDDING, April 23.-At 1:10 this morning a very distinct shock of earthquake was felt here. It lasted about eight seconds and there were two strong pulsations. "The shock caused considerable alarm, particularly among the guests in the various hotels. They were nervous, however, because of the San Francisco horror, and to this fact was due their fright, more than to the severity of the earthquake...." Report 4: Humboldt Standard, 23 Apr 1906; p. 1, c. 4-5 [UNRELIABLE] "... The earthquake this morning lasted eight seconds at Redding, Cal. Chimneys were thrown down and the guests at the Hotel Lorenz rushed into the streets clad only in their night robes." The time of the event is not given in this report, except that it occurred in the morning. Report 5: Humboldt Times, 24 Apr 1906; p. 8, c. 4 [UNRELIABLE] "... At Redding it lasted eight seconds, and a few chimneys tumbled down, and there was a shirttail brigade." Report 6: Ashland Tidings, 23 Apr 1906; p. 3, c. 3 "... Redding, on the south, felt a slight tremor, and there was more or less seismic disturbance through California which disarranged the telegraph lines for an hour." Report 7: Umpqua Valley News, 23 Apr 1906; p. 7, c. 6 [UNRELIABLE] "At half past one o'clock last night there was an earthquake felt at various points throughout Southern Oregon. The tremor was quite perceptible at Grants Pass, where for some twenty seconds the earth trembled and buildings swayed to-and-fro, but no damage resulted. Ashland also felt the same shock. "Further down, in north California the tremor was much stronger. At Redding the chimneys tumbled down and caused considerable confusion, but aside from that there was no damage done." MMI for this location: IV Location Described: Dunsmuir, Siskiyou Co. Report 1: Courier-Free Press (Redding), 23 Apr 1906; p. 1, c. 1 "DUNSMUIR, April 23.-This section was visited by a severe twister at 1:20 o'clock this morning and many people were frightened into the belief that the end of the world had arrived. "The earthquake was most strongly felt on the hill and in the higher sections of town. Down town and along the level of the railroad track the shake resembled the rumbling of a locomotive, an accustomed sound here, and the people did not notice it. "But up on the hill back of the main street there was a lively shaking up of windows, dishes and furniture. "Frank Talmadge, who lives on the hill section, says his house was severely wrenched and shaken. The windows rattled, Talmadge's bed swayed perceptibly and he hastily telephoned down town to see how much damage was done. Clocks were stopped in various parts of town. "The shock awakened all the residents of the hill section and was twice as severe as the one of Wednesday morning." "Twister" is used in this article as a reference to the earthquake. MMI for this location: IV-V (preferred: IV) Location Described: Fort Jones, Siskiyou Co. Report 1: Farmer and Miner (Fort Jones), 25 Apr 1906; p. 3, c. 2 "Another slight earthquake was felt in Fort Jones.... It was feared that more damage might be done around the [San Francisco] bay but the fears were groundless." MMI for this location: Uncertain Location Described: Hornbrook, Siskiyou Co. Report 1: Valley Record (Ashland), 26 Apr 1906; p. 7, c. 6 "A slight shock of Earthquake was felt by some people in Ashland at 1:10 Tuesday morning, also at Sisson, Hornbrook and other points in Siskiyou...." Tuesday would be 24 Apr; later in the same article, however, the date is given as 23 Apr. [The remainder of this article is listed chronologically in this catalog under 23 Apr, under (nearly) identical entries published in the Morning Oregonian (Portland).] Because this source is internally inconsistent, and because the 01:10 time of the event matches the time of an event known to have occurred on 23 Apr (but not on 24 Apr), the obvious inference is that the date stated above ("Tuesday") is in error. It should state the date as being Monday morning, 23 Apr. MMI for this location: Uncertain Location Described: Sisson, Siskiyou Co. (now the town of Mt. Shasta, CA) Report 1: The Searchlight (Redding), 24 Apr 1906; p. 1, c. 1-2, and p. 2, c. 2 "SISSON, April 23-5 a. m.-Two earthquake shocks occurred here this morning at 1:15, though the exact time is in dispute. There was an interval of about fifteen seconds between the shocks, and the last one was much more severe than the first. "The earthquake was almost an exact duplicate of that of last Wednesday morning. Windows rattled, doors were slammed shut, and restless sleepers were awakened. There was a continued tremor between the two shocks, the last one closing the seismic exhibition with a bang." Report 2: Courier-Free Press (Redding), 23 Apr 1906; p. 1, c. 3 "SISSON, April 23.-Sisson folks experienced a very slight shock of earthquake this morning at 1:20 o'clock. The shock was lighter than that of Wednesday and not a particle of damage was done. Windows rattled some." Report 3: Valley Record (Ashland), 26 Apr 1906; p. 7, c. 6 "A slight shock of Earthquake was felt by some people in Ashland at 1:10 Tuesday morning, also at Sisson, Hornbrook and other points in Siskiyou...." Tuesday would be 24 Apr; later in the same article, however, the date is given as 23 Apr. [The remainder of this article is listed chronologically in this catalog under 23 Apr, under (nearly) identical entries published in the Morning Oregonian (Portland).] Because this source is internally inconsistent, and because the 01:10 time of the event matches the time of an event known to have occurred on 23 Apr (but not on 24 Apr), the obvious inference is that the date stated above ("Tuesday") is in error. It should state the date as being Monday morning, 23 Apr. Report 4: Oregon Daily Journal (Portland), 23 Apr 1906; p. 9, c. 6 [UNRELIABLE] "Telephone reports from Crescent City, California, state that that place was severely shaken last night, as was Sisson and other northern California towns." MMI for this location: IV Location Described: Yreka, Siskiyou Co. Report 1: Siskiyou News, 26 Apr 1906; p. 2, c. 5 "There was an earthquake Monday morning about 1 o'clock which was felt by many in Yreka, and telegraph reports state that it was felt from Portland to Sacramento. It was very light and did no damage anywhere, but in the highly wrought state of the people the wildest rumors of damage and destruction were started and for a time found credence. Sam Luttrel was driving from Fort Jones with a load of Yreka passengers. He met a man about three miles out of Yreka driving to Fort Jones who told him that the earthquake had been very severe in Yreka, cracking the Masonic building from top to bottom and doing other material damage. But the quake was hardly perceptible in Yreka and cracked nothing more substantial than some individual's excitable imagination." Report 2: Yreka Journal, 25 Apr 1906; p. 3, c. 4 "... All that occurred in any part of Siskiyou last week, was a slight jar, which stopped a few clocks and made a slight vibration of insignificant force. Clocks stopped at the first shock in San Francisco on the 18th, and the other shock last Sunday night, the 22d, was lighter and did not even stop a clock anywhere...." The event of Sunday night, 22 Apr, is inferred to be the event of the early morning of 23 Apr. The location is not given any more specifically than "Siskiyou," but the paper was published in Yreka. Report 3: The Searchlight (Redding), 24 Apr 1906; p. 2, c. 3-4 "YREKA, April 23-8 a. m.-Two distinct shocks of earthquake were experienced here.... The second shock, coming five or six seconds after the first, was the most severe. Opinions differ as to whether the disturbance this morning was greater than that of last Wednesday morning. People are nervous on the subject of earthquakes and are disposed, naturally, to exaggerate impressions formed. "Mrs. Charles Cady insists that she was almost thrown out of bed by the earthquake.... "No damage whatever has been reported from any quarter of Yreka." Report 4: Courier-Free Press (Redding), 23 Apr 1906; p. 1, c. 3 "YREKA, April 23.-Quite a severe shock of earthquake occurred here at 1:15 o'clock this morning. The shock was felt more distinctly than the one of Wednesday, but no damage was done other than to put a keen edge to the fears of the people. "Windows rattled and people were awakened from sound slumbers." Report 5: Humboldt Standard, 23 Apr 1906; p. 1, c. 4-5 [UNRELIABLE] "... At Yreka it was more severe than on Wednesday [18 Apr]." The time of the event is not given in this report, except that it occurred in the morning. Report 6: Humboldt Times, 24 Apr 1906; p. 8, c. 4 [UNRELIABLE] "The shock was felt at Yreka more severely than the Wednesday quake at that place...." MMI for this location: IV Location Described: Red Bluff, Tehama Co. Report 1: Red Bluff Daily News, 24 Apr 1906; p. 1, c. 2 "Light sleepers were awakened ... by a slight earth tremor which stopped the clocks in the United States Weather Bureau, H. H. Wiedenieck's and G. C. Wilkin's. The shock was felt as far north as Grants' Pass and as far South of here but no damage was done before Mother Earth stopped trembling...." Report 2: Daily People's Cause (Red Bluff), 23 Apr 1906; p. 1, c. 2 "Another shock of earthquake was felt in Red Bluff at about ten minutes to one this Monday morning, although the shock was not so severe as the one of last Wednesday morning. Only a few people felt it as most people were sleeping soundly at that hour. Several clocks about town were stopped by the shock." MMI for this location: IV Location Described: Burnt Ranch, Trinity Co. Report 1: Blue Lake Advocate, 5 May 1906; p. 2, c. 2 "... we were treated to three more temblors about 1 o'clock a.m. No damage was done in this locality; in fact there has been no danger done in Trinity county, that your correspondent has heard of so far." MMI for this location: Uncertain Location Described: Hayfork, Trinity Co. Report 1: The Searchlight (Redding), 26 Apr 1906; p. 3, c. 1 "The earthquake shock ... was not very heavy. No damage was done, but it was a reminder." MMI for this location: Uncertain Location Described: New River, Trinity Co. Report 1: Humboldt Times, 28 Apr 1906; p. 6, c. 2 "another heavy shock" MMI for this location: Uncertain Location Described: Weaverville, Trinity Co. Report 1: Weekly Trinity Journal, 27 Apr 1906; p. 2, c. 1 "...there was another earthquake shock but not so severe as the one of the 18th inst. It was strong enough, however to rouse apprehensions as to damage elsewhere. Fortunately these fears proved unfounded. While the shock was general no damage was suffered in the State beyond the toppling of a few chimneys." Report 2: Courier-Free Press (Redding), 23 Apr 1906; p. 1, c. 2 "WEAVERVILLE, April 23.-Many Weaverville people were awakened from sound slumbers this morning at 1:15 o'clock by a slight earthquake shock and rumbling that lasted possibly two seconds. "The shock here was not so severe as that on Wednesday but the people were of course frightened. All they have heard for five days is earthquake and they are ready to go into a panic at the slightest tremble of the earth. No damage resulted this morning." Report 3: The Searchlight (Redding), 24 Apr 1906; p. 2, c. 2-3 "WEAVERVILLE, April 23.-8 a. m.-Slight shocks of earthquake were felt here at 1:08 this morning. The duration of the temblor was only a few seconds-perhaps six or eight. But few people were awakened by it. The earthquake was very much lighter than that of last Wednesday morning, according to the reports of those who observed both." MMI for this location: IV Location Described: Challenge, Yuba Co. Report 1: Marysville Daily Appeal, 26 Apr 1906; p. 2, c. 1 "... there was a light shock again in the early morning of the 23d." MMI for this location: Uncertain Location Described: Glendale, Douglas Co., Oregon Report 1: Ashland Tidings, 23 Apr 1906; p. 3, c. 3 "Wild rumors flew along the wires this morning from the south of a reported disastrous earthquake throughout Oregon last night. The TIDINGS was called up by phone from Redding to confirm a report that Ashland and Grants Pass had been damaged, but had to deny knowledge of any disturbance here, although some people reported a slight tremor at 1:10 o'clock this morning. Others, including the telegraph operators who were on duty all night here, knew nothing of it. The Grants Pass telephone office reported a slight tremor in that city and at Glendale and Merlin. Redding, on the south, felt a slight tremor, and there was more or less seismic disturbance through California which disarranged the telegraph lines for an hour." Report 2: Medford Mail, 27 Apr 1906; p. 1, c. 1 "Light sleepers-and some of those whose slumbers are usually profound-were aroused about 1:20 Monday morning [in Medford] by a distinct, though comparatively, slight seismic movement. J. S. Howard was awakened by the shock and noted the time-1:20. Dr. Pickel had the same experience and on making a professional call at Central Point later in the morning was asked about the first thing whether the temblor had been felt in Medford or not. Distinct shocks were felt at Ashland, Grants Pass and Glendale." Report 3: Morning Oregonian (Portland), 23 Apr 1906; p. 3, c. 1 [UNRELIABLE] "GLENDALE, Or., April 23.-(Special.)-A distinct shock of earthquake was felt in this city at 11 minutes after 1 o'clock this morning. The shock was apparently heavier than the one of April 18, causing buildings to rock and rattle." MMI for this location: Uncertain Location Described: Ashland, Jackson Co., Oregon Report 1: Ashland Tidings, 23 Apr 1906; p. 3, c. 3 "Wild rumors flew along the wires this morning from the south of a reported disastrous earthquake throughout Oregon last night. The TIDINGS was called up by phone from Redding to confirm a report that Ashland and Grants Pass had been damaged, but had to deny knowledge of any disturbance here, although some people reported a slight tremor at 1:10 o'clock this morning. Others, including the telegraph operators who were on duty all night here, knew nothing of it. The Grants Pass telephone office reported a slight tremor in that city and at Glendale and Merlin. Redding, on the south, felt a slight tremor, and there was more or less seismic disturbance through California which disarranged the telegraph lines for an hour." Report 2: Medford Mail, 27 Apr 1906; p. 1, c. 1 "Light sleepers-and some of those whose slumbers are usually profound-were aroused about 1:20 Monday morning [in Medford] by a distinct, though comparatively, slight seismic movement. J. S. Howard was awakened by the shock and noted the time-1:20. Dr. Pickel had the same experience and on making a professional call at Central Point later in the morning was asked about the first thing whether the temblor had been felt in Medford or not. Distinct shocks were felt at Ashland, Grants Pass and Glendale." Report 3: Valley Record (Ashland), 26 Apr 1906; p. 7, c. 6 "A slight shock of Earthquake was felt by some people in Ashland at 1:10 Tuesday morning, also at Sisson, Hornbrook and other points in Siskiyou...." Tuesday would be 24 Apr; later in the same article, however, the date is given as 23 Apr. [The remainder of this article is listed chronologically in this catalog under 23 Apr, under (nearly) identical entries published in the Morning Oregonian (Portland).] Because this source is internally inconsistent, and because the 01:10 time of the event matches the time of an event known to have occurred on 23 Apr (but not on 24 Apr), the obvious inference is that the date stated above ("Tuesday") is in error. It should state the date as being Monday morning, 23 Apr. Report 4: Umpqua Valley News, 23 Apr 1906; p. 7, c. 6 [UNRELIABLE] "At half past one o'clock last night there was an earthquake felt at various points throughout Southern Oregon. The tremor was quite perceptible at Grants Pass, where for some twenty seconds the earth trembled and buildings swayed to-and-fro, but no damage resulted. Ashland also felt the same shock." Report 5: Eugene Daily Guard, 23 Apr 1906; p. 1, c. 3 "a very slight earthquake shock." The time of the event is not given in this report, except that it occurred in the morning. Report 6: Humboldt Standard, 23 Apr 1906; p. 1, c. 4-5 [UNRELIABLE] "... At Ashland, Oregon, and Grant's Pass it was severe...." The time of the event is not given in this report, except that it occurred in the morning. Report 7: Courier-Free Press (Redding), 23 Apr 1906; p. 1, c. 1 [UNRELIABLE] "ASHLAND, Ore., April 23.-Southern Oregon had a lively shakeup this morning about 1:15 o'clock, but so far no damage has been reported from any point in this section. "The temblor this morning was more severe than the one of Wednesday. Houses shook and windows rattled, dishes were knocked over and people were awakened in every part of the town. "Since the earthquake of Wednesday there have been predictions that Portland and the north coast would be the next to receive a visit from earthquakes, and the people were in a nervous state that was not at all improved by this morning's shake. Many of them ran from their homes in scant attire expecting to see the business part of the town in ruins." Report 8: The Searchlight (Redding), 24 Apr 1906; p. 1, c. 1-2 [UNRELIABLE] "Reports reaching Redding early Monday morning said that the earthquake was heavy in Ashland and Grants Pass, heavier in the latter city, where chimneys were thrown down.... "No damage was done in Ashland and what was done in Grants Pass is hardly worth mentioning." MMI for this location: III Location Described: Medford, Jackson Co., Oregon Report 1: Medford Mail, 27 Apr 1906; p. 1, c. 1 "Light sleepers-and some of those whose slumbers are usually profound-were aroused about 1:20 Monday morning by a distinct, though comparatively, slight seismic movement. J. S. Howard was awakened by the shock and noted the time-1:20. Dr. Pickel had the same experience and on making a professional call at Central Point later in the morning was asked about the first thing whether the temblor had been felt in Medford or not. Distinct shocks were felt at Ashland, Grants Pass and Glendale." Report 2: Daily People's Cause (Red Bluff), 23 Apr 1906; p. 1, c. 2 [UNRELIABLE] "A report was current here today that Medford, Oregon, and Seattle had suffered by the shock, but this report was not confirmed." The statement about Medford "suffering" appears to be exaggerated in comparison with reports from papers near Medford, and there are no reliable reports which suggest that this earthquake was felt in Seattle. MMI for this location: IV Location Described: Grants Pass, Josephine Co., Oregon Report 1: Ashland Tidings, 23 Apr 1906; p. 3, c. 3 "Wild rumors flew along the wires this morning from the south of a reported disastrous earthquake throughout Oregon last night. The TIDINGS was called up by phone from Redding to confirm a report that Ashland and Grants Pass had been damaged, but had to deny knowledge of any disturbance here, although some people reported a slight tremor at 1:10 o'clock this morning. Others, including the telegraph operators who were on duty all night here, knew nothing of it. The Grants Pass telephone office reported a slight tremor in that city and at Glendale and Merlin. Redding, on the south, felt a slight tremor, and there was more or less seismic disturbance through California which disarranged the telegraph lines for an hour." Report 2: Medford Mail, 27 Apr 1906; p. 1, c. 1 "Light sleepers-and some of those whose slumbers are usually profound-were aroused about 1:20 Monday morning [in Medford] by a distinct, though comparatively, slight seismic movement. J. S. Howard was awakened by the shock and noted the time-1:20. Dr. Pickel had the same experience and on making a professional call at Central Point later in the morning was asked about the first thing whether the temblor had been felt in Medford or not. Distinct shocks were felt at Ashland, Grants Pass and Glendale." Report 3: Roseburg Twice A Week Review, 23 Apr 1906; p. 3, c. 4 "GRANTS PASS, Or., April 23-A slight earthquake was felt here and in neighboring towns.... No damage." Report 4: Umpqua Valley News, 23 Apr 1906; p. 7, c. 6 [UNRELIABLE] "At half past one o'clock last night there was an earthquake felt at various points throughout Southern Oregon. The tremor was quite perceptible at Grants Pass, where for some twenty seconds the earth trembled and buildings swayed to-and-fro, but no damage resulted. Ashland also felt the same shock." Report 5: Morning Oregonian (Portland), 23 Apr 1906; p. 3, c. 1 [UNRELIABLE] "GRANTS PASS, Or., April 23.-(Special.)-An earthquake shock which broke some windows and awoke sleeping citizens was felt here at 1:11 this morning. The shock lasted between 15 and 20 seconds and was accompanied by a distinct rumbling noise. The motion of the undulation was from east to west and the oscillation was sufficient to set hanging lamps and pictures to swaying. "Mayor George Good states that the shock was felt all over his house, which is a structure 75 feet in length and two stories high. His children, who were asleep, were awakened and cried out in alarm, and a relative who was sleeping in an adjoining room, despite the fact that he is quite deaf, was aroused by the sway of electric light fixtures attached to the bed. "Within a few minutes after the shock frightened citizens began calling up the local telephone exchange to ascertain the cause of the commotion. The telephone manager had been raised by the shock and was able to allay the fears of all, as practically no damage had been done beyond the breaking of window glass." Report 6: Morning Oregonian (Portland), 24 Apr 1906; p. 7, c. 2 [UNRELIABLE] "GRANTS PASS, Or., April 23.-(Special.)-The heaviest shock of earthquake ever experienced in Southern Oregon was felt in this city at 1:13 A. M. last night. It made doors and windows rattle and awakened many people. A shock not quite so heavy as this was felt here on the morning and to the very minute of the big earthquake that wrecked San Francisco and other California towns." Report 7: Oregon Daily Journal (Portland), 23 Apr 1906; p. 9, c. 6 [UNRELIABLE] "Grants Pass, Or., April 23.-Severe earthquake shocks occurred here at 1 o'clock this morning. The tremor continued for about 20 seconds, rattling windows and doors and stopping clocks. People were awakened, many going out into the streets. At the Hotel Josephine nearly all the guests awoke and came down into the lobby. It was feared for a while that serious damage would result." Report 8: Del Norte Record, 28 Apr 1906; p. 3, c. 2 "... The shock was felt in Grants Pass...." Report 9: Humboldt Standard, 23 Apr 1906; p. 1, c. 4-5 [UNRELIABLE] "... At Ashland, Oregon, and Grant's Pass it was severe...." The time of the event is not given in this report, except that it occurred in the morning. Report 10: Humboldt Times, 24 Apr 1906; p. 8, c. 4 [UNRELIABLE] "As nearly as can be learned the recent shake extended farther north than did the other, and it is reported that Arcata and the towns in the northern part of the county felt the thrill, and that Crescent City and Grants Pass got it stronger than ever before...." Report 11: The Searchlight (Redding), 24 Apr 1906; p. 1, c. 1-2 [UNRELIABLE] "Reports reaching Redding early Monday morning said that the earthquake was heavy in Ashland and Grants Pass, heavier in the latter city, where chimneys were thrown down.... "No damage was done in Ashland and what was done in Grants Pass is hardly worth mentioning." MMI for this location: Uncertain Location Described: Merlin, Josephine Co., Oregon Report 1: Ashland Tidings, 23 Apr 1906; p. 3, c. 3 "Wild rumors flew along the wires this morning from the south of a reported disastrous earthquake throughout Oregon last night. The TIDINGS was called up by phone from Redding to confirm a report that Ashland and Grants Pass had been damaged, but had to deny knowledge of any disturbance here, although some people reported a slight tremor at 1:10 o'clock this morning. Others, including the telegraph operators who were on duty all night here, knew nothing of it. The Grants Pass telephone office reported a slight tremor in that city and at Glendale and Merlin. Redding, on the south, felt a slight tremor, and there was more or less seismic disturbance through California which disarranged the telegraph lines for an hour." MMI for this location: Uncertain Location Described: Eugene, Lane Co., Oregon Report 1: Eugene Daily Guard, 23 Apr 1906; p. 2, c. 1 "The earthquake seems to be moving northward- is getting a little too close for comfort. Grant's Pass, where they felt a tremble early this morning, is less than two hundred miles from Eugene." This comment in the Eugene Daily Guard implies that the earthquake of the morning of 23 Apr was NOT felt in Eugene. MMI for this location: Uncertain, but probably Not Felt Location Described: Portland, Multnomah Co., Oregon Report 1: Courier-Free Press (Redding), 23 Apr 1906; p. 1, c. 2 [UNRELIABLE] "The shake was felt as far north as Portland and Seattle and south in Oakland and San Francisco, though no damage was reported from any section in the state." These statements must be erroneous. The report is not corroborated in either the Oregon Daily Journal or the Morning Oregonian, both of which were published daily in Portland. Also, there are no reliable reports which suggest that this earthquake was felt in Oakland, San Francisco, or Seattle. Report 2: The Searchlight (Redding), 24 Apr 1906; p. 1, c. 1-2 [UNRELIABLE] "An alarming report from Portland, coming no one knew how, was that the city was in flames, the fire having followed the earthquake. This report was soon denied, emphatically, in a dispatch received about 9 o'clock from Ashland." Report 3: Humboldt Standard, 23 Apr 1906; p. 1, c. 4-5 [UNRELIABLE] "Portland, Oregon has received a heavy shock...." The time of the event is not given in this report, except that it occurred in the morning. Again, this report is not corroborated by any Portland newspapers. Report 4: Humboldt Times, 24 Apr 1906; p. 8, c. 4 [UNRELIABLE] "... Even Portland is reported as getting shaken up, in the same manner as Eureka was Wednesday morning, perhaps not so seriously." Once again, this report is not corroborated by any Portland newspapers. Report 5: Oregon Daily Journal (Portland), 23 Apr 1906; p. 9, c. 6 This article, under the title "Southern Oregon Towns Shaken by Quakes," described the earthquake as occurring in southern Oregon and northern California, but it did not mention anything about an earthquake felt in Portland or northern Oregon. This absence strongly suggests that the earthquake was not felt in Portland. Report 6: Morning Oregonian (Portland), 24 Apr 1906; p. 7, c. 2 "WASHINGTON, [D.C.,] April 23.-(Special.)-The Southern Oregon earthquake was recorded on the Government seismograph in this city this morning...." The reference to "Southern Oregon," taken together with the absence of any report of felt earthquakes in Portland on this date, suggests that this aftershock was not felt in Portland or northern Oregon. MMI for this location: Uncertain, but probably Not Felt Location Described: Seattle, King Co., Washington Report 1: Courier-Free Press (Redding), 23 Apr 1906; p. 1, c. 2 [UNRELIABLE] "The shake was felt as far north as Portland and Seattle and south in Oakland and San Francisco, though no damage was reported from any section in the state." These statements must be erroneous. The report is not corroborated in either the Oregon Daily Journal or the Morning Oregonian, both of which were published daily in Portland. Also, there are no reliable reports which suggest that this earthquake was felt in Oakland, San Francisco, or Seattle. Report 2: Daily People's Cause (Red Bluff), 23 Apr 1906; p. 1, c. 2 [UNRELIABLE] "A report was current here today that Medford, Oregon, and Seattle had suffered by the shock, but this report was not confirmed." The statement about Medford "suffering" appears to be exaggerated in comparison with reports from papers near Medford, and there are no reliable reports which suggest that this earthquake was felt in Seattle. MMI for this location: Unreliable Location Described: Northern California and Oregon (in general) Report 1: Daily Colusa Sun, 25 Apr 1906; p. 1, c. 2 [UNRELIABLE] "The northern part of California and the southern portion of Oregon escaped the great earthquake of Wednesday, the 18th, but that portion of our coast has been experiencing shocks of greater or less degree during the past few days. Reports from Portland, Grants Pass, Ashland, Jacksonville and Eugene in Oregon and Redding, Sisson, Weaverville, Yreka, and several other Northern California towns is to the effect that much uneasiness is felt, though no damage has resulted from the shake." Although the date of the event (or events) is not given specifically, it is probably referring to the 23 Apr event. The information in this article does not appear to be entirely accurate. The report of an earthquake felt in Portland is not corroborated in either the Oregon Daily Journal or the Morning Oregonian, both of which were published daily in Portland, nor is the report of an earthquake felt in Eugene corroborated in either the Eugene Daily Guard or the Morning Register, both of which were published daily in Eugene. Report 2: Arcata Union, 25 Apr 1906; p. 1, c. 3-4 [UNRELIABLE] "The earthquake which visited us again on Monday morning, seemed to have worked as far north as Portland, but no great amount of damage is reported from this tremblor." This report appears to be incorrect. The report of an earthquake felt in Portland is not corroborated in either the Oregon Daily Journal or the Morning Oregonian, both of which were published daily in Portland. MMI for this location: Unreliable Other Information: Instrumental Data Report 1: Morning Oregonian (Portland), 24 Apr 1906; p. 7, c. 2 "WASHINGTON, [D.C.,] April 23.-(Special.)-The Southern Oregon earthquake was recorded on the Government seismograph in this city this morning, between 4:25 and 5 o'clock, Washington time, three hours later than Oregon time. The instrument showed the heaviest shock occurred from 4:29 to 4:33, just 17 minutes after it was felt in Oregon. This is exactly the time required for the San Francisco shock to traverse the continent." MMI for this location: N/A TABLE 10: PRIMARY REPORTS FOR THE 25 APR 1906, 15:17 AFTERSHOCK SEE CORRESPONDING FIGURE 7 Location Described: Alameda, Alameda Co. Report 1: Lawson (1908), vol. I, p. 418 felt at Alameda Pier MMI for this location: Uncertain Location Described: Berkeley, Alameda Co. Report 1: Berkeley Daily Gazette, 25 Apr 1906; p. 1, c. 1 "... a severe earthquake was felt in this city which caused a general exodus from the brick buildings in the business section. The temblor was the most severe that has been felt since the one of a week ago this morning, which caused the destruction of San Francisco's business section. "So far as has been learned the earthquake caused no damage in this section, although it is feared a number of the partially wrecked buildings in Oakland and San Francisco may have suffered. "Occupants of the First National Bank building were not alarmed, a majority of them remaining in their offices. "The earthquake was of several seconds duration. Its direction appeared to be from south to north. The officials at the University were unable to give a report of the earthquake this afternoon, but will be prepared to give a seismographic record of today's disturbance and the numerous recent temblors." Report 2: Lawson (1908), vol. I, p. 417 "Walking with Dr. King, not felt by either of us." [Statement of S. Albrecht.] Duration 7 seconds. Lawson (1908) estimates Rossi-Forel intensity IV-V. Time listed for this event is 15:15. It is not clear what justification there is for Lawson's (1908) estimate of R-F intensity IV-V, especially in light of the fact that neither the observer nor his companion felt the shock. Report 3: Lawson (1908), vol. I, p. 418 "2 tremors about 5 s. apart. Time is of last one." Time listed for this event is 15:18:20. MMI for this location: IV-V (preferred: V) Location Described: Niles, Alameda Co. (now the area of Niles District, CA) Report 1: Lawson (1908), vol. I, p. 418 felt at Niles MMI for this location: Uncertain Location Described: Oakland, Alameda Co. Report 1: San Francisco Call, 26 Apr 1906; p. 2, c. 4 "OAKLAND, April 25.-An earthquake jarred this city ... and occasioned another scare. The shock was short and stiff. People were frightened from buildings and many persons hurried for safety into the middle of the streets. In several instances the cracks in structures that were damaged by the great temblor of one week ago were widened and loose plaster and bricks thrown down." Report 2: The Bulletin (San Francisco), 26 Apr 1906; p. 6, c. 2-3 Oakland Herald, 26 Apr 1906; p. 2, c. 3-4 "The shock of earthquake felt at 3:15 yesterday afternoon was No. 37 of the series in which is included the one responsible for starting the fire that caused the destruction of San Francisco. It was a little less than three seconds in duration and would be rated as a number three. Numbers one and two are not perceptible shocks, and can be observed only through the agency of seismic instruments. These registered the earthquake that did all the damage in the city as a number nine. "At the Chabot Observatory, Oakland, it was said today that the shock felt yesterday was much lighter than the average layman thought. "'The people are now all tuned up for shocks,' said Professor Burckhalter, 'and they unconsciously exaggerate the dimensions of the slightest quake. That of yesterday afternoon was of a significance hardly worth talking about. Instruments are fortunately without nerves and have enabled us to be assured that it was incapable of any material consequence.'" It is not clear whether the statement in the first paragraph about it lasting three seconds and being "rated as a number three" describes the earthquake in San Francisco or Oakland. By comparison to reports in the Oakland Enquirer (27 Apr) and The Bulletin (28 Apr), it appears as though all of this information came from Professor Burckhalter at Chabot Observatory in Oakland; still, there are minor inconsistencies between all three reports that are puzzling. Report 3: Oakland Enquirer, 27 Apr 1906; p. 2, c. 5 "Professor Burckhalter of the Chabot Observatory states that the earthquake which occurred yesterday afternoon at fifteen minutes after 3 o'clock, was only a small one, in spite of the miniature panic it caused. It lasted only two seconds, he says, and ordinarily would hardly be noticed. "It was rumored that yesterday's shake was due to an extra large dynamite explosion in San Francisco. Professor Burckhalter says that such was not the case, and that the dynamiting over there has no effect on the earth's crust over here." Although the earthquake is stated to have occurred "yesterday," the report almost certainly refers to the earthquake at around 15:15 on 25 Apr; compare this with the report in The Bulletin (San Francisco), 26 Apr 1906, p. 6, c. 2-3. Report 4: The Bulletin (San Francisco), 28 Apr 1906; p. 7, c. 1 [quoting Professor Burckhalter of the Chabot Observatory in Oakland:] "'... The intensity of earthquakes I have graded into ten classes ... the disturbance that is barely perceptible to a human being I call the No. 1. The earthquake of Wednesday morning, April 18, was a No. 9.... "'There was a shock felt yesterday afternoon at 1 o'clock, but it was of but a very short duration and was classed as a No. 3. The shock which was felt Wednesday at 4:30 in the afternoon was of no longer duration but was of No. 4 intensity. The others which have been felt since Wednesday of last week have been of No. 2 and No. 3 and No. 1 intensity and of less degree which I have not recorded.'" "The shock ... at 4:30" almost certainly refers to the earthquake at around 15:15 on 25 Apr; compare this with the report in The Bulletin (San Francisco), 26 Apr 1906, p. 6, c. 2-3. Report 5: Oakland Times, 26 Apr 1906; p. 1, c. 4 "... there was an earthquake shock which, while not serious in its consequences, nevertheless had the effect of badly frightening people. Many rushed from their homes bareheaded and into the streets, looking at each other with blanched faces, fearing a repetition of the shock of last week. Practically no damage was done, only a few loose bricks toppling from their shaky positions, not having been securely replaced since the earth quake of April 18. The shock yesterday consisted of one short, sharp 'jerk.' It is said by the scientists that it was one of the to be expected 'settling' shocks caused by the earth's crust in the affected region adjusting its self to the conditions caused by the great quake. "The building inspecting authorities say that no damage whatever was caused by the shock...." Report 6: Santa Cruz Morning Sentinel, 26 Apr 1906; p. 1, c. 3 "OAKLAND, Cal., April 25.-Oakland and the cities of San Francisco bay were visited by another earthquake shock.... The shock was not severe, but it lasted fully ten seconds. No buildings were reported damaged anew and no lives lost." Report 7: Marysville Daily Appeal, 26 Apr 1906; p. 1, c. 5-6 "OAKLAND, April 25.-At 3:20 o'clock this afternoon another earthquake shock was felt in this city, which caused consternation in many quarters and especially among the sufferers who were made homeless by the shock of a week ago. As far as can be learned the tremblor did no material damage, although a number of rickety walls were shaken down. So far no loss of life has been reported. "At Oakland mole the trains which were standing on the tracks ready to receive passengers, were moved several feet by the force of the shock. "The tremblor was sufficient to cause a small wave on the bay, which, so far as learned, did no damage to shipping. "Out at the different camps of refugees consternation reigned for a short time, but the soldiers on guard quickly quelled the disturbance and quieted the fears of the sufferers." Some of the statements from Oakland are difficult to believe and may weaken the article's credibility. Report 8: Fresno Morning Republican, 26 Apr 1906; p. 1, c. 1-2 "OAKLAND, April 25.-A sharp shock of earthquake was felt here at 3:20 o'clock. It lasted about seven or eight seconds." From this article, it is not clear whether "3:20" refers to 3:20 am or 3:20 pm; however, by comparison to similar reports, the time is inferred to be in the afternoon. Report 9: Lawson (1908), vol. I, p. 417 Duration 3 seconds. Lawson (1908) estimates Rossi-Forel intensity III. Time listed for this event is 15:15. Report 10: Lawson (1908), vol. I, p. 417 "Noticed ... on clock marked U. S. Observatory." Time listed for this event is 15:17:15. MMI for this location: IV-V (preferred: IV) Location Described: Antioch, Contra Costa Co. Report 1: Lawson (1908), vol. I, p. 418 felt at Antioch MMI for this location: Uncertain Location Described: Martinez, Contra Costa Co. Report 1: Daily Gazette (Martinez), 26 Apr 1906; p. 1, c. 4 "Martinez experienced a very heavy shock of earthquake shortly after 3 o'clock Wednesday afternoon. The tremblor was the heaviest since the one of April 18th and shook buildings violently, rattled dishes and caused the entire population to make a rush for the streets, in fear of a repetition of the earthquake that wrecked half of California. As far as can be ascertained, no serious damage was done beyond giving everyone a good scare. A plate glass window in Bergamini's store was thrown down." MMI for this location: IV-V (preferred: V) Location Described: Point Bonita, Marin Co. Report 1: Lawson (1908), vol. I, p. 417 "Direction NW., no tremor, just a jar, 1 max. strongest at beginning, no sound, may have been blasting." Duration 2 seconds. Lawson (1908) estimates Rossi-Forel intensity V. MMI for this location: Uncertain Location Described: Napa, Napa Co. Report 1: Lawson (1908), vol. I, p. 417 "Sharp." Townley and Allen (1939) describe this as "slight," but as their source is presumed to be Lawson (1908), it is assumed that Townley and Allen incorrectly copied the information. Report 2: Napa Daily Journal, 27 Apr 1906; p. 2, c. 1 "The shake at 3:15 Wednesday afternoon caused one death in San Francisco, the victim being Mrs. Annie Whitaker...." The article gives the impression that the writer expected people to already be aware of the earthquake; this would probably be the case only if it was felt locally; hence, it is inferred that the earthquake was felt in Napa; however, the inference is not without uncertainty. MMI for this location: Uncertain Location Described: Napa Redwoods, Napa Co. Report 1: Napa Daily Journal, 28 Apr 1906; p. 2, c. 2 "... yesterday at 3:25 p. m. one of the hardest, though but short, since [the mainshock]...." This was part of a long article written by a regular correspondent, dated "Napa Redwoods, April 27, 1906." "Yesterday" would therefore suggest the earthquake occurred on 26 Apr. It is possible, however, that the first part of the article, containing the above passage, was written a day before the article was signed and dated, in which case "yesterday" may refer to the 25 Apr event instead. MMI for this location: Uncertain [may have been a different event] Location Described: Yountville, Napa Co. Report 1: Lawson (1908), vol. I, p. 417 "Undulatory twist, quite severe." MMI for this location: Uncertain Location Described: Sacramento, Sacramento Co. Report 1: Marysville Daily Appeal, 26 Apr 1906; p. 1, c. 5-6 "SACRAMENTO, April 25.-The earthquake which occurred at San Francisco was hardly noticeable here." MMI for this location: II Location Described: Mile Rocks, San Francisco Co. Report 1: Lawson (1908), vol. I, p. 417 "Slight." Durham (1998) identifies two locations named Mile Rocks, one in Sonoma County and the other in San Francisco County. Looking at the maps in the atlas portion of Lawson (1908), the San Francisco County "Mile Rocks" location is on Maps 4, 17, and 19, whereas the Sonoma County location of that name is not on any of the maps. From this, the inference is made that "Mile Rocks" in the list of aftershocks in Lawson (1908) refers to the San Francisco County location. MMI for this location: Uncertain Location Described: San Francisco, San Francisco Co. Report 1: Diary of Charles Prinegar (San Francisco, CA), 25 Apr 1906 (pp. 74-78) "... At three o'clock another earth quake came that nearly tore the Post Office down. I was on third floor and thought my time had surely come when bricks and marble and such began to fall all around me...." Report 2: Diary of Charles Prinegar (San Francisco, CA), 26 Apr 1906 (pp. 78-81) "... There were a great many killed yesterday when the quake came by falling walls and it does not look good to me.... "I would like to see one of the eastern papers for the papers out here does [sic] not say a thing about the disaster or never mentions a soul that was injured or killed. All they tell about is the heroic work that people have done and where the homeless can get relief, etc...." Report 3: Diary of Charles Prinegar (San Francisco, CA), 30 Apr 1906 (pp. 102-110) "... If I had only known that there would not be any more earth-quakes I could just as well kept on at the Post Office and be making two dollars per day. I would have to walk four miles to work and the same at night, but I would have done it, if that quake had not come the first day I worked there. It scared me about as bad as the first one did, and I did not want to take any chances, every one that comes weakens the building that much more, and it looks now as if it would fall at any time...." Although this event scared the writer "about as bad as the first one did," he also wrote in his diary, on 29 Apr 1906, that all the aftershocks put together "would hardly make as great a one as the first one was." Report 4: San Francisco Examiner, 26 Apr 1906; p. 1, c. 3 "There was a distinct shock at 3:15 yesterday afternoon. It was felt all over the city, and caused general alarm. People in houses ran into the street. Those in the parks and streets did not notice it and were surprised when told there had been another seismic disturbance.... "Mrs. Whitaker was at work in the kitchen of her home on Shotwell street in the Mission district when the shock came. The chimney, which had been left in a tottering condition by the heavy quake last Wednesday, crashed through the roof upon the young woman.... "The shock did no serious damage to property. Not a building was harmed to any extent. Here and there bricks in unstable chimneys fell. "It was one of several small shocks which have followed the big earthquake of April 18th...." Report 5: San Francisco Chronicle, 26 Apr 1906; p. 2, c. 3 "... A slight earthquake shock which was felt in the city shortly after 3 o'clock [yesterday afternoon] caused a leaning chimney at 308 Shotwell street to topple over and crash through the roof of the house...." Report 6: Oakland Enquirer, 26 Apr 1906; p. 8, c. 3 "An earthquake shook San Francisco at half-past 3 o'clock yesterday afternoon. It was a little more severe than any that have occurred since the day of the big temblor. In the section of the ruins a few bricks were thrown out of place, but no walls fell and there was only one fatality. "Mrs. Tillie L. Whittaker of 308 Shotwell street lost her life. A chimney fell from a building adjoining her home, crashed through the roof and falling bricks and debris fractured Mrs. Whittaker's skull.... The chimney that fell was about two stories above the roof of her dwelling and timbers, plaster, and shingles went down with a roar...." Report 7: Oakland Times, 26 Apr 1906; p. 1, c. 4 "... In San Francisco a number of tottering walls were thrown down." Report 8: Lawson (1908), vol. I, p. 417 "Double waves recorded on seismograph." Time listed for this event is 15:17:10. MMI for this location: V Location Described: San Francisco Peninsula Report 1: Lawson (1908), vol. I, p. 417 "Strongly felt on ground, causing landsliding along coast cliffs, lasting 10 s. with a slight repetition after 10 s." Duration 15 seconds. Lawson (1908) estimates Rossi-Forel intensity V. The duration listed in the "Duration" column (15 seconds) is inconsistent with the duration as described under "Remarks." MMI for this location: Uncertain Location Described: Stockton, San Joaquin Co. Report 1: The Evening Mail (Stockton), 26 Apr 1906; p. 3, c. 5 "A slight shock of earthquake was felt.... In high buildings it was quite perceptible and in some residences it caused temporary alarm, although many persons did not feel it at all." Report 2: Stockton Daily Evening Record, 26 Apr 1906; p. 8, c. 4 "Another slight earthquake was felt.... The vibration was very light and many did not notice it." MMI for this location: II Location Described: Mount Hamilton, Santa Clara Co. Report 1: Lawson (1908), vol. I, p. 418 Lawson (1908) estimates Rossi-Forel intensity II-III. Time listed for this event is 15:17:40. MMI for this location: Uncertain Location Described: San Jose, Santa Clara Co. Report 1: San Jose Mercury, 26 Apr 1906; p. 7, c. 4 "An earthquake lasting about four seconds was perceptible.... It did no damage as far as could be ascertained, but the shock was sufficient to send people rushing from their homes in terror of a repetition of Wednesday's disaster. The disturbance was registered at Lick Observatory, but very faintly." MMI for this location: IV Location Described: Vallejo, Solano Co. Report 1: Fresno Morning Republican, 26 Apr 1906; p. 1, c. 6-7 "VALLEJO, April 25.-A severe earthquake shock was felt.... The temblor lasted two seconds and the oscillation was from north to south. The people ran from residences and stores in a greatly alarmed condition and the schools were quickly dismissed. No danger [sic] is reported." MMI for this location: IV TABLE 11: PRIMARY REPORTS FOR THE 17 MAY 1906, 20:21 AFTERSHOCK SEE CORRESPONDING FIGURE 8 Location Described: Alameda, Alameda Co. Report 1: Lawson (1908), vol. I, p. 422 felt at Alameda Pier MMI for this location: Uncertain Location Described: Berkeley, Alameda Co. Report 1: Berkeley Daily Gazette, 18 May 1906; p. 1, c. 6 "An earthquake occurred last night at 8 o'clock 31 minutes and 29 seconds which lasted eight seconds, but did no damage whatever. "The temblor was felt in all parts of the city and many nervous people scampered from their homes fearing that a repetition of the one of April 18 was at hand. The effect of the temblor on most buildings was described as having a grinding sensation, but no damage resulted...." It is not entirely clear which locations are meant by "all parts of the city"; however, it was a common practice of the time to refer to San Francisco simply as "the city." It is inferred that this description applies, at least in part, to the city of Berkeley. It probably also applies to San Francisco, and perhaps to other Bay Area locations as well. Report 2: Lawson (1908), vol. I, p. 422 "East-west." Duration 8 seconds. Felt in the Faculty Club at U.C. Berkeley. MMI for this location: Uncertain Location Described: Livermore, Alameda Co. Report 1: Livermore Echo, 24 May 1906; p. 1, c. 3 "A sharp earthquake shock was felt here about 8:24 o'clock last Thursday evening, and caused lights, etc., suspended from the ceiling to sway quite perceptibly." Report 2: Livermore Herald, 19 May 1906; p. 2, c. 1 "There was a lively earthquake shock Thursday evening about 8:25 which reminded nervous people that the ground is not yet stable." MMI for this location: IV Location Described: Oakland, Alameda Co. Many newspapers outside the Bay Area reported the earthquake in Oakland. Many of these reports were very similar, appearing to come from the same original source, although in other cases some of the reports appeared to be exaggerated. In general, distal reports such as these are considered less reliable than proximal reports (such as those which are listed below), hence the distal reports are not listed. Report 1: Oakland Enquirer, 18 May 1906; p. 10, c. 2 Oakland Times, 18 May 1906; p. 1, c. 1 "Last evening at 8:20 there was another earthquake shock of about two seconds' duration, which sent hearts jumping, for while it lasted it was rather energetic. So far as is known there was no damage." Report 2: Oakland Times, 18 May 1906; p. 1, c. 3 "At twenty minutes past eight o'clock last night an earthquake of some force shook Oakland and had enough energy back of it to throw many people into a considerable scare. Some were so badly done out of their wits that they refused to go to bed for the remainder of the night and camped on their doorsteps. The City Council committees were in session at the time. Although thick in the business of ordinances and resolutions each separate city father dropped his work. Several men in the lobby rose and left the room. City Attorney McElroy confessed to being frightened, and the faces of others went white. But it is confidently expected that there will be no other quake of sufficient force to do any damage." Report 3: Oakland Tribune, 18 May 1906; p. 4, c. 2 "While the members of the City Council were deep in the consideration of municipal business during the meeting of the Council committees last night ... an earthquake rocked the City Hall, and in an instant the business of the meeting was forgotten. Councilmen and lobby ___* seized their hats, and made ready to fly to the safety of the open air, should the shock become more violent. "Several gentlemen ... took no chances but left the Council chamber with more haste than dignity and sought safety in the ___* until assured that the ___* was over. When satisfied that there was no danger of the immediate destruction of the City Hall by the convulsions of Mother Earth, those who had fled returned, the City Fathers resumed the business which had been interrupted and the earthquake was forgotten." * This word is illegible. Report 4: Berkeley Daily Gazette, 18 May 1906; p. 1, c. 6 "... In Oakland persons ran from the buildings into the streets, and while very perceptible in all parts of the city no damage was done...." Report 5: San Francisco Chronicle, 18 May 1906; p. 1, c. 6 "OAKLAND, May 17.-A slight shock of earthquake, lasting several seconds, occurred on this side of the bay at 8:15 o'clock to-night. While sharp enough to be perceptible all over the city, it was not heavy enough to do any damage." Report 6: Lawson (1908), vol. I, p. 422 "Chandelier swung with period of 1.25 s. Shock NW.-SE. at Vernon St." Duration 12 seconds. Lawson (1908) estimates Rossi-Forel intensity IV-V. MMI for this location: IV Location Described: Crockett, Contra Costa Co. Report 1: Daily Gazette (Martinez), 19 May 1906; p. 4, c. 1 "CROCKETT ITEMS ... May 18, 1906.... A baby temblor caused hearts to come up in the mouths for a few seconds last night." MMI for this location: III Location Described: Bolinas, Marin Co. Report 1: Lawson (1908), vol. I, p. 422 Duration 8 seconds. Lawson (1908) estimates Rossi-Forel intensity III. MMI for this location: Uncertain Location Described: Point Bonita, Marin Co. Report 1: Lawson (1908), vol. I, p. 422 "Nearly vertical. Direction N., no tremor, just a jar, 1 max., strongest at beginning. No sound, may have been blasting." Duration 2 seconds. MMI for this location: Uncertain Location Described: Potter Valley, Mendocino Co. Report 1: Ukiah Republican Press, 25 May 1906; p. 4, c. 5 "POTTER, May 22.-.... Two shocks of earthquake were experienced here Thursday evening last...." The time of the event is not given in this report, except that it occurred in the evening. A lack of felt reports anywhere between Napa and Potter Valley suggests that the event felt in Potter Valley was not the same as the event felt in the San Francisco Bay Area and to the south. MMI for this location: Uncertain [may have been a different event] Location Described: Corral de Tierra, Monterey Co. Report 1: Salinas Daily Index, 18 May 1906; p. 1, c. 4 "... Reports from ... Corral de Tierra ... show that the shock was felt, but no damage was done." MMI for this location: Uncertain Location Described: Gonzales, Monterey Co. Report 1: Lawson (1908), vol. I, p. 422 felt at Gonzales MMI for this location: Uncertain Location Described: King City, Monterey Co. Report 1: King City Rustler, 18 May 1906; p. 1, c. 5 "Last night at about 8:45 windows began rattling, slightly at first, but presently in an ominously violent manner, causing people to look at each other in an inquiring sort of manner that seemed to say: 'Isn't about time to hike outside?' "The trembling lasted about 18 seconds, then came a succession of thumps that only lasted a few seconds, but rocked some of the people out of their houses pretty lively. It was nearly as severe as No. 1 of the Big Series that came on the 18th of last month, but unlike that one, it was not followed up. No damage whatsoever was done here." MMI for this location: IV Location Described: Monterey, Monterey Co. Report 1: Salinas Daily Index, 18 May 1906; p. 1, c. 4 "... Reports from ... Monterey ... show that the shock was felt, but no damage was done." MMI for this location: Uncertain Location Described: Point Pińos, Monterey Co. Report 1: Lawson (1908), vol. I, p. 422 "Horizontal. Two max. alike, sound like water in pipe with air in it." Duration 22 seconds. MMI for this location: Uncertain Location Described: Salinas, Monterey Co. Many newspapers outside the Salinas area reported the earthquake in Salinas. Many of these reports were very similar, appearing to come from the same original source, although in other cases some of the reports appeared to be exaggerated. In general, distal reports such as these are considered less reliable than proximal reports (such as those which are listed below), hence the distal reports are not listed. Report 1: Salinas Daily Index, 18 May 1906; p. 1, c. 4 "There was another perceptible earthquake shake last night at 8:25. Residents on Main Street are making records for themselves in getting down stairs and out of public buildings...." Report 2: Salinas Weekly Journal, 19 May 1906; p. 3, c. 3 (Under the heading "From Friday's Daily Journal":) "A sharp shock of earthquake here at 8:25 last evening caused many persons to rush into the street." Report 3: San Jose Mercury, 18 May 1906; p. 1, c. 2 [UNRELIABLE] (Under the heading "By the Associated Press":) "SALINAS, May 17.-An earthquake shock, the heaviest since April 18, was felt here about 8:15 this evening. The shock, which was accompanied by a heavy rumble, came from the northeast to southwest and lasted 21 seconds. No damage was done." The wording of this article is remarkably similar to the description in the Times-Gazette of Redwood City (19 May 1906, p. 3, c. 7), describing the effects in Menlo Park. As the latter piece appears as part of a regular column, and not as part of an Associated Press report, the latter is deemed more reliable, and the report in the San Jose Mercury is ignored. Report 4: Lawson (1908), vol. I, p. 422 felt in Salinas MMI for this location: V ? Location Described: Napa, Napa Co. Report 1: Napa Register, 25 May 1906; p. 5, c. 4 "An earthquake shock that was barely perceptible in Napa occurred at 8:15 Thursday evening...." It is not clear whether the date of this event was 17 or 24 May; however, based on the timing of the event and on other felt reports in the area on 17 May (and not on 24 May) it is presumed that this is the 17 May event. Report 2: Lawson (1908), vol. I, p. 422 felt in Napa MMI for this location: II Location Described: Sacramento, Sacramento Co. Report 1: The Home Alliance (Woodland), 18 May 1906; p. 2, c. 1 [UNRELIABLE] "... It is reported as being quite severe in Sacramento." This statement is almost certainly erroneous. No newspapers in or near Sacramento reported feeling the earthquake locally. MMI for this location: Unreliable Location Described: Panoche, San Benito Co. Report 1: The Free Lance (Hollister), 25 May 1906; p. 4, c. 2 (Under the heading "Panoche Items":) "There was quite a heavy shock here last Thursday night." MMI for this location: Uncertain Location Described: Mile Rocks, San Francisco Co. Report 1: Lawson (1908), vol. I, p. 422 "Vertical. Strongest in middle." Duration 35 seconds. Durham (1998) identifies two locations named Mile Rocks, one in Sonoma County and the other in San Francisco County. Looking at the maps in the atlas portion of Lawson (1908), the San Francisco County "Mile Rocks" location is on Maps 4, 17, and 19, whereas the Sonoma County location of that name is not on any of the maps. From this, the inference is made that "Mile Rocks" in the list of aftershocks in Lawson (1908) refers to the San Francisco County location. MMI for this location: Uncertain Location Described: San Francisco, San Francisco Co. A number of newspapers outside the Bay Area reported the earthquake in San Francisco. Most of these reports were very similar, appearing to come from the same original source, although in other cases some of the reports appeared to be exaggerated. In general, distal reports such as these are considered less reliable than proximal reports (such as those which are listed below), hence the distal reports are not listed. Report 1: Berkeley Daily Gazette, 18 May 1906; p. 1, c. 6 "... The temblor was felt in all parts of the city and many nervous people scampered from their homes fearing that a repetition of the one of April 18 was at hand. The effect of the temblor on most buildings was described as having a grinding sensation, but no damage resulted...." It is not entirely clear which locations are meant by "all parts of the city"; however, it was a common practice of the time to refer to San Francisco simply as "the city." It is inferred that this description applies, at least in part, to the city of Berkeley. It probably also applies to San Francisco, and perhaps to other Bay Area locations as well. Report 2: Santa Cruz Morning Sentinel, 18 May 1906; p. 1, c. 5 "... The shock was felt in San Francisco.... The Associated Press reports that no damage was done...." Report 3: Lawson (1908), vol. I, p. 422 "Moderate rolling motion." MMI for this location: IV ? Location Described: Southampton Shoal, San Francisco Co. Report 1: Lawson (1908), vol. I, p. 422 "Southeast-northwest. Rumbling before shake and continuing 2 s. after." Duration 2 seconds. MMI for this location: Uncertain Location Described: Yerba Buena, San Francisco Co. Report 1: Lawson (1908), vol. I, p. 422 "Light." Yerba Buena probably refers to the lighthouse station on Yerba Buena Island in San Francisco Bay (Lawson collected a lot of aftershock data from lighthouse stations), although it may instead refer to the land grant of that name in Santa Clara County. MMI for this location: Uncertain Location Described: San Francisco Peninsula Report 1: Lawson (1908), vol. I, p. 422 "About the heaviest since first shock, causing people to rush out-of-doors." Duration 20 seconds. Lawson (1908) estimates Rossi-Forel intensity VI. MMI for this location: Uncertain Location Described: Stockton, San Joaquin Co. Report 1: The Evening Mail (Stockton), 18 May 1906; p. 3, c. 3 "There was a slight earthquake shock last evening at 8:30. It was not generally felt, and there was no damage." Report 2: Stockton Daily Evening Record, 18 May 1906; p. 5, c. 2 "A slight shock of earthquake was felt in this city about 8:15 o'clock last evening. The shock was so slight that not more than one in three persons felt it." MMI for this location: II Location Described: San Luis Obispo, San Luis Obispo Co. Report 1: San Luis Obispo Tribune, 22 May 1906; p. 7, c. 3 "Many in this city felt a slight earthquake shock about 8:40 o'clock last evening." Although the reference to "last evening" would imply the event took place on 21 May 1906, this article was printed in a box otherwise comprised of reports of the event on 17 May. The 20:40 event time matches the time given in all the other reports in the "box" (which all describe the 17 May event). Most likely, this "box" was first published in the daily version of this paper, on 18 May 1906, then reprinted verbatim in the San Luis Obispo Tribune, a semi-weekly paper. When it was reprinted, "last evening" was not corrected as it should have been to reflect the passage of several days' time. The daily version of this paper could not be located. Report 2: Santa Cruz Morning Sentinel, 18 May 1906; p. 1, c. 5 "... The shock was felt ... slightly at San Luis Obispo. The Associated Press reports that no damage was done...." MMI for this location: III-IV (preferred: III) Location Described: Menlo Park, San Mateo Co. Report 1: Times-Gazette (Redwood City), 19 May 1906; p. 3, c. 7 (Under the heading "Menlo Park Occurrences":) "An earthquake shock, the heaviest since April 18, was felt here about 8:15 Thurs. evening. The shock, which was accompanied by a heavy rumble, came from the northeast to southwest and lasted 21 seconds. No damage was done." MMI for this location: IV ? Location Described: Campbell, Santa Clara Co. Report 1: Lawson (1908), vol. I, p. 422 "Violent." MMI for this location: Uncertain Location Described: Los Gatos, Santa Clara Co. Report 1: Los Gatos Mail, 24 May 1906; p. 4, c. 1 "The temblor last Thursday evening at 8:20 was a pretty big chunk of the jar. Those who know, however, say it only felt like thirty cents compared with the dollar kind they had April 18th." Report 2: San Jose Mercury, 19 May 1906; p. 12, c. 5 "LOS GATOS, May 18.-No serious damage was done by last night's temblor, which was the most severe shake since April 18th. It occurred about twenty minutes past 8 o'clock." Report 3: San Francisco Chronicle, 18 May 1906; p. 1, c. 6 "... At Los Gatos and along the foothills, where the shock of April 18th was lightest and did the least damage, [this] shock was felt more distinctly than in [San Jose]. Some plaster was knocked down in various places." Report 4: Berkeley Daily Gazette, 18 May 1906; p. 1, c. 6 "... At Los Gatos and along the foothills the temblor was felt more distinctly than in the cities and plastering was shaken from the walls in many homes." Report 5: Lawson (1908), vol. I, p. 422 "Short, but with considerable vertical motion." Lawson (1908) estimates Rossi-Forel intensity V. MMI for this location: VI Location Described: Mount Hamilton, Santa Clara Co. Report 1: Lawson (1908), vol. I, p. 422 "Vertical slightly, 2 max. 5 s. and 10 s. after beginning, mean of two observers." Duration 14 seconds. Lawson (1908) estimates Rossi-Forel intensity IV. MMI for this location: Uncertain Location Described: San Jose, Santa Clara Co. Many newspapers outside the Bay Area reported the earthquake in San Jose. Many of these reports were very similar, appearing to come from the same original source, although in other cases some of the reports appeared to be exaggerated. In general, distal reports such as these are considered less reliable than proximal reports (such as those which are listed below), hence the distal reports are not listed. Report 1: San Jose Mercury, 18 May 1906; p. 9, c. 1 "The most severe shock since the earthquake of April 18 was experienced yesterday evening at 8.21.16. The vibrations east and west, lasted approximately fifteen seconds, beginning easily and ending with considerable violence. No damage has been reported. In the Jose Theater an incipient panic was quelled by the presence of mind of those on the stage, who continued their lines and declined to be interrupted." Report 2: San Francisco Chronicle, 18 May 1906; p. 1, c. 6 "SAN JOSE, May 17.-A sharp earthquake was felt in this city this evening. At the Lick Observatory the shock continued for ten seconds, and was severest at 8:26 o'clock. "No damage occurred in this city, nor, so far as could be ascertained, in the neighborhood. "A mild panic, however, prevailed for some time all over the city and surroundings. People rushed from their homes and remained outside for hours. Many are bringing their tents again into use. Two automobiles felt the shock distinctly, although traveling at a rapid pace. "At the San Jose Theater, where the Frank Bacon company was presenting 'The Hills of California,' the audience commenced to stampede, but was quieted. No one was injured...." Report 3: San Francisco Examiner, 18 May 1906; p. 3, c. 4 "SAN JOSE, May 17.-Frightened by prophesies of the world's end, hundreds of women became panic stricken to-night when what seemed the heaviest shock since April 18th rocked the town. Despite the apparent force of the temblor, however, not even the shakiest walls were injured or disturbed. "At the Jose Theatre a crowded house rose as the lights upon the stage went out, and rushed towards the doors. The coolness of the employees and several other men stopped the panic before any one had been injured. Although many left the theatre, the performance was continued. For days San Jose has been deeply agitated over the mysterious appearance upon the fences and dead walls of the city of placards and signs predicting the speedy end of the earth.... "When the shock came to-night the scenes throughout the residence section of the city were those of a wildly disturbed community. Women rushed from every house screaming and terrorstricken. Crying to one another that the end of the world had come, they dashed from their homes without a thought of consequences. The efforts to calm them by the men that remained collected were futile-their fear was not one that could be reasoned with. Blind, unreasoning terror, superstitious fright, was all powerful. There was scarcely a street upon which were not huddled frightened groups of women seeking refuge from the houses that rocked with the force of the quake. To persuade the nervous to return to the houses was a difficult task, and in a few instances impromptu tents formed the night's shelter." MMI for this location: V Location Described: Sunnyvale, Santa Clara Co. Report 1: San Jose Mercury, 19 May 1906; p. 12, c. 4 "SUNNYVALE, May 18.-At 8:20 p.m. we experienced another jar, lasting about ten seconds. It occasioned some anxiety and uneasiness, but no damage was done." MMI for this location: IV Location Described: Boulder Creek, Santa Cruz Co. Report 1: The Mountain Echo (Boulder Creek), 19 May 1906; p. 3, c. 2 "There was another quite heavy shock of earthquake at 8:24 Thursday evening, causing many people to hurriedly vacate their homes for the streets and sidewalks." MMI for this location: V Location Described: Santa Cruz, Santa Cruz Co. Report 1: Santa Cruz Morning Sentinel, 18 May 1906; p. 1, c. 5 "A little more severe earthquake shock than usual was felt in this city at 8:30 on Thursday evening, lasting for about ten seconds. "Although the vibrations in many buildings on Pacific Av. were quite noticeable, and in fact all over the city, there was very little alarm, no one was hurt and not a pane of glass nor a piece of plaster was broken, so far as known...." Report 2: Santa Cruz Surf, 18 May 1906; p. 8, c. 1 "The hardest shock of earthquake since the one on the 18th of April was felt last evening. There was practically no damage, but the shock was heavy enough to drive people into the street." MMI for this location: IV-V (preferred: V) Location Described: Watsonville, Santa Cruz Co. Report 1: Santa Cruz Morning Sentinel, 18 May 1906; p. 1, c. 5 "... The shock was felt in ... Watsonville.... The Associated Press reports that no damage was done...." Report 2: Salinas Daily Index, 18 May 1906; p. 1, c. 4 "... Reports from ... Watsonville ... show that the shock was felt, but no damage was done." Report 3: San Luis Obispo Tribune, 22 May 1906; p. 7, c. 2-3 "... Reports from Watsonville and Salinas state that the shock was quite severe at both those places." MMI for this location: Uncertain Location Described: Vallejo, Solano Co. Report 1: The Tuolumne Independent (Sonora), 19 May 1906; p. 3, c. 4 "... A shock was also felt at Vallejo...." Report 2: Union Democrat (Sonora), 19 May 1906; p. 1, c. 4 "A telephone message received in Sonora Thursday night at nine o'clock announced another severe earthquake shock in San Francisco, Oakland, San Jose, and Vallejo. No damage was reported." The date and time of the event are not stated in the article, but it is inferred to be the event of the night of 17 May. MMI for this location: Uncertain Location Described: Modesto, Stanislaus Co. Report 1: Modesto Daily Evening News, 18 May 1906; p. 4, c. 3 "A slight earthquake was felt here at 8:23 o'clock last evening. It jarred the chandeliers a bit, but that was about all." MMI for this location: III Location Described: Oakdale, Stanislaus Co. Report 1: Lawson (1908), vol. I, p. 422 "Very slight...." MMI for this location: Uncertain Location Described: Woodland, Yolo Co. Report 1: The Home Alliance (Woodland), 18 May 1906; p. 2, c. 1 "A slight earthquake shock was felt here last night...." Report 2: Sacramento Bee, 18 May 1906; p. 7, c. 1 "... A slight shock of earthquake was felt by a number of people in Woodland last night." MMI for this location: III Location Described: Marysville, Yuba Co. Report 1: Marysville Daily Appeal, 18 May 1906; p. 4, c. 2 "Word was received in this city last night that another quite severe earthquake was felt at San Francisco last evening about 8 o'clock. No damage was done." From the nature of this report, it appears that the earthquake was not felt in Marysville. Contrary to the implication of this report, the earthquake does not appear to have been felt "severely" in San Francisco. MMI for this location: Uncertain, but probably Not Felt TABLE 12: PRIMARY REPORTS FOR THE 6 JUL 1906, 22:55 AFTERSHOCK SEE CORRESPONDING FIGURE 9 Location Described: Coalinga, Fresno Co. Report 1: Hanford Weekly Sentinel, 12 Jul 1906; p. 2, c. 3 "A report came over the railroad wire Saturday saying that there was an earthquake shock in Coalinga at about 10 o'clock Friday night. The report stated that the Odd Fellows were holding a meeting, and the severity of the jar caused the company to hurry onto the streets. No damage is reported from the temblor, but the people were badly frightened...." Report 2: Hanford Daily Journal, 7 Jul 1906; p.5, c. 3 "An earthquake shock, lasting several seconds, visited Coalinga shortly after 10 o'clock last night, causing no damage, but almost creating a panic at a meeting of the local lodge of Odd Fellows, which was in session at the time...." Report 3: Fresno Morning Republican, 8 Jul 1906; p. 7, c. 4 "HANFORD, July 7.-A slight earthquake shock was felt in Coalinga, Lemoore and Hanford shortly after 10 o'clock last night. It was most severe in Coalinga, where it was of sufficient power to cause considerable fright. No damage has been reported." Report 4: Tulare County Times (Visalia), 12 Jul 1906; p. 2, c. 2 (Under the heading "(From Saturday's Daily Times)":) "It was rumored around town today that a severe earthquake was felt last night at Coalinga, Volta, and Los Banos. At the two former places the shock was quite severe and many people rushed out of their houses. The shock occurred about 11 p. m." MMI for this location: V Location Described: Fresno, Fresno Co. Report 1: Fresno Morning Republican, 8 Jul 1906; p. 7, c. 4 "HANFORD, July 7.-A slight earthquake shock was felt in Coalinga, Lemoore and Hanford shortly after 10 o'clock last night. It was most severe in Coalinga, where it was of sufficient power to cause considerable fright. No damage has been reported." The lack of a report from Fresno in this or in other Fresno newspapers suggests that this earthquake was not felt in Fresno. MMI for this location: Uncertain, but probably Not Felt Location Described: Hanford, Kings Co. Report 1: Hanford Weekly Sentinel, 12 Jul 1906; p. 2, c. 3 "A report came over the railroad wire Saturday saying that there was an earthquake shock in Coalinga at about 10 o'clock Friday night. The report stated that the Odd Fellows were holding a meeting, and the severity of the jar caused the company to hurry onto the streets. No damage is reported from the temblor, but the people were badly frightened. "Railroad men coming from Lemoore Saturday morning, said that the shock was felt there at about the same time that Coalinga was shaken, but the jar was not so perceptible. The disturbance was felt here by a few, and was apparently very slight, but Hanford will not be envious of the two towns to the west on account of their being favored by a greater shock." Report 2: Hanford Daily Journal, 7 Jul 1906; p.5, c. 3 "... several Hanfordites state that the trembling was slightly noticeable in this city." Report 3: Fresno Morning Republican, 8 Jul 1906; p. 7, c. 4 "HANFORD, July 7.-A slight earthquake shock was felt in Coalinga, Lemoore and Hanford shortly after 10 o'clock last night. It was most severe in Coalinga, where it was of sufficient power to cause considerable fright. No damage has been reported." MMI for this location: II Location Described: Lemoore, Kings Co. Report 1: Hanford Weekly Sentinel, 12 Jul 1906; p. 2, c. 3 "A report came over the railroad wire Saturday saying that there was an earthquake shock in Coalinga at about 10 o'clock Friday night. The report stated that the Odd Fellows were holding a meeting, and the severity of the jar caused the company to hurry onto the streets. No damage is reported from the temblor, but the people were badly frightened. "Railroad men coming from Lemoore Saturday morning, said that the shock was felt there at about the same time that Coalinga was shaken, but the jar was not so perceptible. The disturbance was felt here by a few, and was apparently very slight, but Hanford will not be envious of the two towns to the west on account of their being favored by a greater shock." Report 2: Hanford Daily Journal, 7 Jul 1906; p.5, c. 3 "... Brakeman Roberts, of the Coalinga-Goshen S. P. passenger train, reports that the shock was plainly felt by him in Lemoore...." Report 3: Fresno Morning Republican, 8 Jul 1906; p. 7, c. 4 "HANFORD, July 7.-A slight earthquake shock was felt in Coalinga, Lemoore and Hanford shortly after 10 o'clock last night. It was most severe in Coalinga, where it was of sufficient power to cause considerable fright. No damage has been reported." MMI for this location: III ? Location Described: Los Banos, Merced Co. Report 1: Tulare County Times (Visalia), 12 Jul 1906; p. 2, c. 2 (Under the heading "(From Saturday's Daily Times)":) "It was rumored around town today that a severe earthquake was felt last night at Coalinga, Volta, and Los Banos. At the two former places the shock was quite severe and many people rushed out of their houses. The shock occurred about 11 p. m." Report 2: Lawson (1908), vol. I, p. 426 felt in Los Banos MMI for this location: III ? Location Described: Volta, Merced Co. Report 1: Tulare County Times (Visalia), 12 Jul 1906; p. 2, c. 2 [UNRELIABLE] (Under the heading "(From Saturday's Daily Times)":) "It was rumored around town today that a severe earthquake was felt last night at Coalinga, Volta, and Los Banos. At the two former places the shock was quite severe and many people rushed out of their houses. The shock occurred about 11 p. m." It seems unlikely that Volta would have a sufficiently higher intensity than Los Banos, given the proximity of the two locations, the similar underlying geology, and the fact that the epicenter is almost certainly closer to Los Banos than to Volta. MMI for this location: Uncertain Location Described: King City, Monterey Co. Report 1: Salinas Daily Index, 11 Jul 1906; p. 1, c. 4 "KING CITY, July 10.-This section was treated to quite a severe shock of earthquake last Friday night at 10:50 o'clock. No damage." MMI for this location: IV ? Location Described: Salinas, Monterey Co. Report 1: Lawson (1908), vol. I, p. 426 felt in Salinas MMI for this location: Uncertain Location Described: San Lucas, Monterey Co. Report 1: Salinas Daily Index, 10 Jul 1906; p. 1, c. 4 "SAN LUCAS, July 9th.-San Lucas was startled by an earthquake about 11 o'clock Friday night nearly as heavy as the one April the 18th. So far no damage has been reported." MMI for this location: IV ? Location Described: San Luis Obispo, San Luis Obispo Co. Report 1: Semi-Weekly Breeze (San Luis Obispo), 10 Jul 1906; p. 5, c. 2 "Some did and others did not feel a slight temblor at seven minutes to 11 o'clock...." MMI for this location: III Location Described: Mount Hamilton, Santa Clara Co. Report 1: Lawson (1908), vol. I, p. 426 "Light. East to west." MMI for this location: Uncertain Location Described: Santa Cruz, Santa Cruz Co. Report 1: Semi-Weekly Breeze (San Luis Obispo), 10 Jul 1906; p. 5, c. 2 "... Reports from Santa Cruz and Watsonville state that several distinct shocks were felt, but no damage was done. However there is no cause for alarm as a slight shock is a daily occurrence in the northern cities." MMI for this location: III Location Described: Watsonville, Santa Cruz Co. Report 1: Semi-Weekly Breeze (San Luis Obispo), 10 Jul 1906; p. 5, c. 2 "... Reports from Santa Cruz and Watsonville state that several distinct shocks were felt, but no damage was done. However there is no cause for alarm as a slight shock is a daily occurrence in the northern cities." MMI for this location: III Location Described: Visalia, Tulare Co. Report 1: Tulare County Times (Visalia), 12 Jul 1906; p. 2, c. 2 (Under the heading "(From Saturday's Daily Times)":) "It was rumored around town today that a severe earthquake was felt last night at Coalinga, Volta, and Los Banos. At the two former places the shock was quite severe and many people rushed out of their houses. The shock occurred about 11 p. m." The nature of this report, and the lack of a report from Visalia in this or in other Visalia newspapers, suggest that this earthquake was not felt in Visalia. MMI for this location: Uncertain, but probably Not Felt TABLE 13: PRIMARY REPORTS FOR THE 5 JUN 1907, 00:27 AFTERSHOCK SEE CORRESPONDING FIGURE 10 Location Described: Alameda, Alameda Co. Report 1: Alameda Daily Argus, 5 Jun 1907; p. 1, c. 7 "There was a sharp earthquake shock at 12:30 o'clock this morning. The shock was one of the most severe since the big quake of April of last year, and rocked houses and agitated timid nerves. Some wall pieces and ornaments were hurled to the floor in several homes, but no chimneys were cracked or other damage sustained. "Mr. Perrine of 2138 Alameda avenue, father of Professor Charles Perrine, the well known astronomer, possesses the only seismograph in Alameda.... The record shows three-quarters of an inch, almost directly east and west, with a slight variation to the southeast and northwest. "According to Mr. Perrine the shock occurred at exactly 12:29." MMI for this location: V Location Described: Berkeley, Alameda Co. Report 1: Berkeley Daily Gazette, 5 Jun 1907; p. 1, c. 3 "There was a baby earthquake in Berkeley about 12:30 o'clock this morning. It was not a very serious affair, but as it was slow in action nervous people feared that it might be preliminary to a more serious disturbance. Light sleepers in frail buildings were awakened, but it was such a minor shake that they turned over and went to sleep again.... No damage whatever is reported. "The seismograph at the students' observatory caught the records distinctly and the belief is that the center of the vibrations was about fifty miles away. Here is the official reading of the seismograph: "'The earthquake of this morning started at 12:26:37 P. S. T. The preliminary tremor lasted for six seconds when the main shock began. This was in two parts, the first and more severe lasting for twenty-one seconds, the other lasting for twenty-eight seconds, giving a total duration of 49 seconds for the main shock. The Omori Seismograph from which these data have been taken showed smaller tremors for nearly three minutes. The direction of the vibrations was from southwest to northeast. A greater disturbance is shown in the east and west component than in the north and south. The center of the shock is about fifty miles distant. The maximum amplitude of the shock is one-one-hundredth of an inch.'" Report 2: Townley and Allen (1939), p. 145 "[Rossi-Forel] Intensity IV to V at Berkeley.... "At Berkeley this shock wrote the largest seismogram obtained to that date on the instrument installed at the University of California in June of the previous year, with maximum amplitude of 251 µ and 1.9 seconds period in the east-west component, and an interval L-P of six seconds, corresponding to a distance of origin of about thirty miles." Report 3: Oak Park Ledger, 7 Jun 1907; p. 1, c. 4 [UNRELIABLE] "... Berkeley was almost shaken to pieces last Tuesday night...." This is almost certainly the 5 Jun 1907 event. The tone of this article was that of an editorial, and the descriptions were without doubt exaggerated. No measure of credibility should be given to the description of shaking above. MMI for this location: IV Location Described: Dimond, Alameda Co. Report 1: Townley and Allen (1939), p. 145 "Dimond, near Oakland, distinct" MMI for this location: Uncertain Location Described: Livermore, Alameda Co. Report 1: Livermore Echo, 6 Jun 1907; p. 1, c. 3 "A short sharp shock of earthquake was felt here at 12:25 Wednesday morning, followed by a lighter shake, and many light sleepers were awakened." Report 2: Livermore Herald, 8 Jun 1907; p. 3, c. 1 "A sharp shock of earthquake was felt here Wednesday morning about 12:30. It was accompanied by a subterranean roar which was much more noticeable than that which preceded the big quake last year." Report 3: Townley and Allen (1939), p. 145 "Reports with no description came from ... Livermore, Alameda Co. ..." MMI for this location: IV Location Described: Mills College, Alameda Co. Report 1: Townley and Allen (1939), p. 145 "Reports with no description came from ... Mills College, ... Alameda Co. ..." MMI for this location: Uncertain Location Described: Oakland, Alameda Co. Report 1: The Bulletin (San Francisco), 5 Jun 1907; p. 1, c. 5 Oakland Tribune, 5 Jun 1907; p. 10, c. 2 "... The seismograph at Chabot observatory in Oakland registered an observation quite different from that of Professor McAdie [in San Francisco]. According to the Chabot instrument the earthquake occurred at 12:27, two minutes later than in [San Francisco], lasted three seconds and had a general direction of from northwest to southeast. It was a number five shock, according to the Oakland observation." It is probable that by "number five" the article is referring to the intensity on the Rossi-Forel scale. A Rossi-Forel V corresponds, very roughly, with a Modified Mercalli Intensity V. Report 2: Mother Lode Magnet (Jamestown), 5 Jun 1907; p. 3, c. 5 "There was a lively shake up by el temblor about San Francisco bay at shortly past midnight last night. A phone message from Oakland this a. m. states that no damage of note was done...." Report 3: The Morning Echo (Bakersfield), 5 Jun 1907; p. 1, c. 2-6 "... By telephone to Oakland it was learned that a very severe earthquake was felt at 12:45 in San Francisco, Oakland and other cities as far south as Stockton.... "The telephone operator at Oakland said that no reports of serious damage had been received up to 2 o'clock. "A later report by telephone from the telephone operator at Oakland said that the shock occurred at 12:38 and lasted 11 seconds. The shock caused great terror, but so far it appeared that little damage had been done." Report 4: Townley and Allen (1939), p. 145 "Oakland, rather heavy, of five seconds duration" MMI for this location: Uncertain Location Described: Martinez, Contra Costa Co. Report 1: Contra Costa Gazette, 8 Jun 1907; p. 5, c. 1 (Under the heading "FROM THURSDAY'S DAILY":) "On Wednesday morning, somewhere about 12:30 a.m., there was a short but pretty sharp earthquake shock. It was noticed by a good many who were not asleep at the time and it woke up quite a number." MMI for this location: IV Location Described: Fresno, Fresno Co. Report 1: The Morning Echo (Bakersfield), 5 Jun 1907; p. 1, c. 2-6 "... By telephone to Oakland it was learned that a very severe earthquake was felt at 12:45 in San Francisco, Oakland and other cities as far south as Stockton. No shock was felt at Fresno or in this city.... "A later report by telephone from the telephone operator at Oakland said that the shock occurred at 12:38 and lasted 11 seconds. The shock caused great terror, but so far it appeared that little damage had been done." MMI for this location: Not Felt Location Described: Bakersfield, Kern Co. Report 1: The Morning Echo (Bakersfield), 5 Jun 1907; p. 1, c. 2-6 "... By telephone to Oakland it was learned that a very severe earthquake was felt at 12:45 in San Francisco, Oakland and other cities as far south as Stockton. No shock was felt at Fresno or in this city.... "A later report by telephone from the telephone operator at Oakland said that the shock occurred at 12:38 and lasted 11 seconds. The shock caused great terror, but so far it appeared that little damage had been done." MMI for this location: Not Felt Location Described: Kentfield, Marin Co. Report 1: Townley and Allen (1939), p. 145 "Kentfield, Marin Co., sharp" MMI for this location: Uncertain Location Described: Napa, Napa Co. Report 1: Napa Daily Journal, 6 Jun 1907; p. 3, c. 3 "A distinct shock of earthquake was felt in this city at 12:25 Wednesday morning." Report 2: Townley and Allen (1939), p. 145 "Napa State Hospital, light" MMI for this location: III ? Location Described: Sacramento, Sacramento Co. Report 1: San Francisco Call, 5 Jun 1907; p. 3, c. 7 [UNRELIABLE] "... The dispatcher at Oakland pier stated that no reports of the temblor's having been felt in the interior had been received except from Sacramento. No damage was reported." The nature of this report, and the lack of any corroborating reports, makes the Sacramento report seem rather questionable. MMI for this location: Unreliable Location Described: San Francisco, San Francisco Co. Many newspapers outside San Francisco reported the earthquake in San Francisco. Some of these reports appear to be based upon reports that are listed below, and they contain no new information. Only reports with unique information are listed below. Report 1: The Bulletin (San Francisco), 5 Jun 1907; p. 1, c. 5 "A heavy earthquake shock startled this city from its sleep this morning when the day was just twenty-five minutes old. It lasted for several seconds and was felt distinctly in all parts of town. No damage has been reported. "According to Professor McAdie, of the Weather Bureau, the temblor ranks as number four in the seismic scale. The earthquake of April last year ranks as number nine...." It is probable that by "number four" the article is referring to the intensity on the Rossi-Forel scale. A Rossi-Forel IV corresponds, very roughly, with a Modified Mercalli Intensity IV. Report 2: San Francisco Call, 5 Jun 1907; p. 3, c. 7 "Two small but distinct earthquake shocks were felt in San Francisco and the bay cities at 12:26 this morning...." Report 3: Sacramento Star, 5 Jun 1907; p. 1, c. 5 "SAN FRANCISCO, June 5.-An earthquake shock of easy, undulating movement and lasting several seconds occurred in San Francisco and vicinity at 12:40 this morning. The shock was the longest since the great quake of April, 1906, but it caused no damage. Hundreds of persons rushed into the streets in their night clothes but the excitement soon subsided when it was found that no damage was done." Report 4: San Jose Mercury, 5 Jun 1907; p. 1, c. 4 "SAN FRANCISCO, June 4.-An earthquake shock lasting about ten seconds was felt here at 12:27 this morning. The oscillation was from north to south. No damage has been reported." The date on this report clearly should be June 5, not June 4. Many other newspapers carried the same report, also with the incorrect dateline. A few papers, including the Stockton Daily Independent (5 June 1907; p. 1, c. 4) carried the report and corrected the date to read June 5. Report 5: Evening Pajaronian (Watsonville), 5 Jun 1907; p. 1, c. 5 "San Francisco, June 5.-This city and neighboring cities bordering on the bay experienced a severe earthquake shock shortly after midnight.... No serious damage is reported." Report 6: The Morning Echo (Bakersfield), 5 Jun 1907; p. 1, c. 2-6 [UNRELIABLE] "Reports reached here early this morning by way of the railroad telegraph lines of an earthquake shock in San Francisco, occurring some time after midnight. The Southern Pacific operator in the Flood building said that the shock seemed as heavy as the one that caused the disaster of last spring. The furniture in the office danced about the room. So far as the railroad operator knew the damage in the city was not great. The wires were working well. "By telephone to Oakland it was learned that a very severe earthquake was felt at 12:45 in San Francisco, Oakland and other cities as far south as Stockton.... "The telephone operator at Oakland said that no reports of serious damage had been received up to 2 o'clock. "A later report by telephone from the telephone operator at Oakland said that the shock occurred at 12:38 and lasted 11 seconds. The shock caused great terror, but so far it appeared that little damage had been done." In comparison to other reports from San Francisco, this account seems greatly exaggerated. MMI for this location: IV-V (preferred: IV) Location Described: Stockton, San Joaquin Co. Several newspapers outside Stockton reported the earthquake in Stockton. These reports appear to be based upon one of the reports listed below, and they contain no new information. Only reports with unique information are listed below. Report 1: Stockton Daily Independent, 5 Jun 1907; p. 5, c. 4 "At 12:40 o'clock this morning a tremblor lasting from one and a half to two seconds was distinctly felt in Stockton. Persons sleeping in second stories were at a loss to know just what caused the disturbance and one after another sought the telephone to verify their impressions. Operators along the Associated Press wires from San Francisco reported having felt the shock." Report 2: Stockton Daily Evening Record, 5 Jun 1907; p. 5, c. 4 "Stockton was visited by a slight temblor at 12:40 this morning that lasted from one and a half to two seconds. Residents sleeping in upper stories were at a loss to know just what caused the disturbance and sought the telephones to verify their impressions. Telegraph operators along the wires between here and San Francisco reported having felt the shock." MMI for this location: III Location Described: San Luis Obispo, San Luis Obispo Co. Report 1: Semi-Weekly Breeze (San Luis Obispo), 7 Jun 1907; p. 4, c. 5 "San Francisco, June 5.-San Francisco and the bay cities experienced a sharp earthquake at 12:30 this morning. There was no damage done, but the shocks were severe and the people were very much excited. "Shocks were felt as far south as San Jose...." The nature of this report, and the lack of a report from San Luis Obispo in this or in other San Luis Obispo newspapers, suggest that this earthquake was not felt in San Luis Obispo. MMI for this location: Uncertain, but probably Not Felt Location Described: Half Moon Bay, San Mateo Co. Report 1: Los Gatos Mail, 20 Jun 1907; p. 5, c. 3 "The earthquake last week injured a concrete building in course of construction at Half Moon Bay, opening a gap an inch wide from top to bottom, says the advocate." The original article (which may have been printed in the Coast Advocate, published in Half Moon Bay) could not be located, and the date it was originally published is uncertain; it may have been as much as a week old by the time it was re-printed in the Los Gatos Mail. The date of the event is even less certain. MMI for this location: Uncertain [may have been a different event] Location Described: Menlo Park, San Mateo Co. Report 1: Townley and Allen (1939), p. 145 "Reports with no description came from ... Menlo Park, San Mateo Co. ..." MMI for this location: Uncertain Location Described: Redwood City, San Mateo Co. Report 1: Times-Gazette (Redwood City), 8 Jun 1907; p. 3, c. 6 (Under the heading "NEWS GATHERED IN REDWOOD CITY AND VICINITY":) "An earthquake visited this community Wednesday morning at 12:25 which made up in severity what it lacked in duration." MMI for this location: Uncertain Location Described: San Gregorio, San Mateo Co. Report 1: Redwood City Democrat, 13 Jun 1907; p. 3, c. 3 "SAN GREGORIO, June 12-.... Two heavy shocks of earthquake were felt during the week at San Gregorio." The dates of the two events are not known, but most likely, they are the events of 5 Jun and 10 Jun. MMI for this location: Uncertain [may have been a different event] Location Described: Alma, Santa Clara Co. Report 1: Diary of Henry Lloyd Tevis (Alma, CA), 5 Jun 1907 "Weather overcast all day. Quite a heavy earthquake shock occurred during the night. Examiner said it was 'No. 4.' E.L.D. returned on morning train and met H.L.T. at 4:20 San Jose in the Large Loco [sic]." According to T. Toppozada (CDMG; written comm., 2001), two sets of diaries for each year exist-one for the ranch and one for the office. Tevis did not write the diaries, his valet did. No mention is given of the valet's name. Tevis lived in Alma, outside of Los Gatos on the road to Santa Cruz. He was an early California millionaire and had a ranch near Los Gatos and a house in San Francisco. The location where the aforementioned earthquake was felt is not stated but is inferred from the rest of the diary entry. MMI for this location: Uncertain Location Described: Campbell, Santa Clara Co. Report 1: Townley and Allen (1939), p. 145 "Campbell, Santa Clara Co., light" MMI for this location: Uncertain Location Described: Los Gatos, Santa Clara Co. Report 1: Los Gatos Mail, 6 Jun 1907; p. 1, c. 4 "At 12:27 o'clock yesterday morning occurred a quite determined jolt occasioned by some internal disturbance of Mother Earth. The shock lasted five or six seconds, perhaps, and caused many a person to 'sit up and take notice.' Some even got out of bed and out into the cold, cold world evidently from fear that something might drop. But nothing did drop or fall down, and so far as has been learned no damage was done...." Report 2: Los Gatos News, 7 Jun 1907; p. 3, c. 1 "There was a shock of earthquake the other evening that would have been unnoticed if it had not been for the experience of last year. Everybody is looking for trouble and excitement. Every little counts." Based on the time reported from nearby communities, this was probably the earthquake of the early morning of 5 Jun. Report 3: Townley and Allen (1939), p. 145 "Los Gatos, a few miles farther west [than Campbell], light" MMI for this location: IV Location Described: Mountain View, Santa Clara Co. Report 1: Mountain View Register, 7 Jun 1907; p. 3, c. 3 "A little earthquake shock was felt by the citizens of Mountain View last Tuesday night at about 12:30. It was felt all along the peninsula but no damage is reported. In San Francisco it lasted about ten seconds while here it was only about six. It is hard to explain the thoughts of a person when old mother earth begins to rock even though she merely disturbs your midnight slumbers." MMI for this location: Uncertain Location Described: Mount Hamilton, Santa Clara Co. Report 1: Townley and Allen (1939), p. 145 "[Rossi-Forel Intensity] II at Mount Hamilton" MMI for this location: Uncertain Location Described: Palo Alto, Santa Clara Co. Report 1: Daily Palo Alto Times, 5 Jun 1907; p. 4, c. 2 "The earth trembled at 12:27 this morning. The shock was probably the most severe that has been experienced since the day of the historic shakeup. The shock this morning lasted six seconds and was felt all along the peninsula and the shake was accompanied by a rumbling noise. No damage was done." MMI for this location: Uncertain Location Described: San Jose, Santa Clara Co. Many newspapers outside San Jose reported the earthquake in San Jose. Some of these reports appear to be based upon one of the reports listed below, and they contain no new information. Only reports with unique information are listed below. Report 1: San Jose Mercury, 5 Jun 1907; p. 1, c. 4 "SAN FRANCISCO, June 4.-An earthquake shock ... was felt here at 12:27 this morning.... "The same shock was experienced in San Jose, lasting about six seconds and of sufficient violence to send many people in lodging houses down town hustling from their beds into the street, there to gather in groups and recall past unpleasantries. No damage has been reported." The date on this report clearly should be June 5, not June 4. Many other newspapers carried a similar report with an incorrect dateline. A few papers, including the Evening Mail of Stockton (5 June 1907; p. 1, c. 7) carried the report and corrected the date to read June 5. Report 2: Evening Pajaronian (Watsonville), 5 Jun 1907; p. 1, c. 5 "San Francisco, June 5.-This city and neighboring cities bordering on the bay experienced a severe earthquake shock shortly after midnight.... No serious damage is reported. San Jose also felt the shock severely." Report 3: Townley and Allen (1939), p. 145 "Reports with no description came from ... San Jose." This report establishes the date and time of the event as 5 Jun 1907, 00:27. MMI for this location: IV-V (preferred: V) Location Described: Santa Clara, Santa Clara Co. Report 1: Townley and Allen (1939), p. 145 "severe at Santa Clara, duration six to seven seconds" MMI for this location: Uncertain Location Described: Boulder Creek, Santa Cruz Co. Report 1: Townley and Allen (1939), p. 145 "Reports with no description came from ... Boulder Creek, Santa Cruz Co. ..." MMI for this location: Uncertain Location Described: Peachland, Sonoma Co. Report 1: Townley and Allen (1939), p. 145 "Reports with no description came from ... Sonoma and Peachland, Sonoma Co. ..." MMI for this location: Uncertain Location Described: Sonoma, Sonoma Co. Report 1: Sonoma Index-Tribune, 8 Jun 1907; p. 3, c. 1 "There was quite a heavy shock on Wednesday morning, at 12:20...." Report 2: Townley and Allen (1939), p. 145 "Reports with no description came from ... Sonoma and Peachland, Sonoma Co. ..." MMI for this location: III ? Location Described: Jamestown, Tuolumne Co. Report 1: Mother Lode Magnet (Jamestown), 5 Jun 1907; p. 3, c. 5 "There was a lively shake up by el temblor about San Francisco bay at shortly past midnight last night.... The shock was distinctly felt throughout Tuolumne county." MMI for this location: III ? TABLE 14: PRIMARY REPORTS FOR THE 8 AUG 1907 AFTERSHOCKS at 04:44 and 06:05 SEE CORRESPONDING FIGURE 11 On the early morning of 8 Aug 1907, two moderate earthquakes (along with several smaller ones) occurred in the Humboldt County vicinity. Based on the majority of the descriptions, the two larger earthquakes seem to be similar, although three reports identify contrasts between the two: according to the Humboldt Standard, "the second was the heavier" in Eureka, and according to two reports in the Humboldt Times, the first one was longer in Eureka, and the hardest was at about 5:00 in Upper Mattole. In the table below (and in the accompanying map), we assume that the two events were similar in size and location, although the first event may have been somewhat closer to Upper Mattole, and the second event may have been somewhat closer to Eureka. Location Described: Arcata, Humboldt Co. Report 1: Humboldt Times, 13 Aug 1907; p. 2, c. 1-2 "... Thursday morning two light [earthquake shocks] were felt...." MMI for this location: Uncertain Location Described: Blocksburg, Humboldt Co. Report 1: Humboldt Standard, 10 Aug 1907; p. 7, c. 7 "Blocksburg, August 8-.... Today about 4:45 a. m. we were treated to a decided jolt, and at 6:15 a. m. we had a sharp movement north and south...." MMI for this location: Uncertain Location Described: Blue Lake, Humboldt Co. Report 1: Humboldt Times, 11 Aug 1907; p. 8, c. 1 "BLUE LAKE, August 10.-Quite a heavy earthquake was felt here early Thursday morning." MMI for this location: Uncertain Location Described: Eureka, Humboldt Co. Report 1: Humboldt Standard, 8 Aug 1907; p. 1, c. 3 "Two light earthquake shocks were felt this morning, the first at 4:39 o'clock and the second about 6 o'clock. The vibrations were from north to south and each lasted about six seconds. The second was the heavier but neither did any damage." Report 2: Humboldt Times, 9 Aug 1907; p. 3, c. 1 "Two very light earthquake shocks were felt yesterday morning, the first occurring at 4:44 o'clock and the second at 6:05 o'clock. The vibrations came from a southerly to northerly direction and lasted during the first shock six seconds. The second shock lasted about three seconds...." Report 3: Townley and Allen (1939), p. 145 "1907 August 8. 4:44 a.m. and 6:05 a.m. At Eureka: 'very light, duration about six seconds, neither maximum nor minimum intensity, only steady shaking of the earth.'" This compilation of reports is attributed to the U.S. Weather Bureau (Form 1009). It is not clear whether the descriptions refer to the 04:44 event, the 06:05 event, or both. MMI for this location: IV ? Location Described: Falk, Humboldt Co. Report 1: Humboldt Standard, 12 Aug 1907; p. 3, c. 1 "Falk, August 8-Two light earthquake shocks were felt here this morning, the first about 4:30 and the second at 6 o'clock. No damage was done." MMI for this location: Uncertain Location Described: Ferndale, Humboldt Co. Report 1: Humboldt Times, 9 Aug 1907; p. 3, c. 1 "... At Ferndale three shocks were felt one at 4:45 o'clock another at 5:15 and the third at 6:10 o'clock. The shocks were of but short duration and did no damage to the valley town." Report 2: Humboldt Standard, 9 Aug 1907; p. 7, c. 1-2 "Ferndale, August 8-.... Our people were awakened in the early hours this morning by a couple of slight shocks of earthquake...." MMI for this location: IV Location Described: Garberville, Humboldt Co. Report 1: Humboldt Standard, 13 Aug 1907; p. 7, c. 4 "Garberville, Aug. 9.-.... Did you feel the earthquake? was the first question asked yesterday morning, when a couple met on the street, and it was not only one but two good sized quakes we were treated to, the first occurring at 4:55 o'clock in the morning, and the second a few moments after 6 o'clock." Report 2: Humboldt Times, 14 Aug 1907; p. 6, c. 2-3 "GARBERVILLE, Aug. 11-.... Thursday morning we were shaken up twice before six o'clock...." MMI for this location: IV ? Location Described: Grizzly Bluff, Humboldt Co. Report 1: Humboldt Times, 10 Aug 1907; p. 2, c. 3 "GRIZZLY BLUFF, Aug. 9.-.... [Thursday] morning ... we experienced two decided shocks within about an hour of each other." MMI for this location: IV ? Location Described: Pepperwood, Humboldt Co. Report 1: Humboldt Standard, 10 Aug 1907; p. 7, c. 7 "Pepperwood, Aug. 8-.... Two heavy earthquakes were felt this morning but no damage was done, only a few things were knocked down in Young's store. One was at 5:15 and the other at 6:05 a. m." MMI for this location: V Location Described: Upper Mattole, Humboldt Co. Report 1: Humboldt Standard, 12 Aug 1907; p. 3, c. 4 "Upper Mattole, August 8-There were two heavy shocks of earthquake at this place this morning. The first about 4:45 and the second about 6 a. m. They were both lively shakes and caused some people to run for open ground. No damage was done." Report 2: Humboldt Times, 13 Aug 1907; p. 2, c. 4 "UPPER MATTOLE, Aug. 9.-Several sharp shocks of earthquake were felt here yesterday morning, the hardest being about 5 o'clock." Report 3: Townley and Allen (1939), p. 145 "1907 August 8. 4:44 a.m. and 6:05 a.m. Upper Mattole, Humboldt Co. 'Quite severe, followed by several lighter shocks during the month.'" This compilation of reports is attributed to the U.S. Weather Bureau (Form 1009). It is not clear whether the descriptions refer to the 04:44 event, the 06:05 event, or both. MMI for this location: V Location Described: Branscomb, Mendocino Co. Report 1: Townley and Allen (1939), p. 145 "1907 August 8. 4:44 a.m. and 6:05 a.m. ... felt at Branscomb, Mendocino Co." This compilation of reports is attributed to the U.S. Weather Bureau (Form 1009). MMI for this location: Uncertain Location Described: Ruth, Trinity Co. Report 1: Humboldt Standard, 27 Aug 1907; p. 7, c. 7 "Ruth, Trinity Co., August 23-.... We know that Mother Earth is very uneasy for the temblors of the 9th, 11th, and 12th insts. were quite hard, but the one on the 18th at 3:20 p. m. was the most severe...." The reported date of this event (9 Aug) is probably incorrect, as it is described here as quite hard, but no other locality reported an event on that date; it is probably the 8 Aug event. MMI for this location: Uncertain [may have been a different event] TABLE 15: PRIMARY REPORTS FOR THE 11 AUG 1907, 04:19 AFTERSHOCK SEE CORRESPONDING FIGURE 12 Location Described: Chico, Butte Co. Report 1: The Searchlight (Redding), 13 Aug 1907; p. 1, c. 3-4 "CHICO, August 12.-An earthquake was distinctly felt in Chico at 4:30 or a little later yesterday morning. Many people were awakened by the shock and their tales agree with those few late retirers who were still up as to the time and duration of the quake. It lasted something less than a quarter of a minute. No damage." Report 2: Chico Record, 13 Aug 1907; p. 5, c. 1 "A slight earthquake shock was felt in this city.... The tremor seemed to extend between Redding and Sacramento. No damage was done." MMI for this location: IV Location Described: Oroville, Butte Co. Report 1: Oroville Daily Register, 12 Aug 1907; p. 1, c. 5 "A slight earthquake shock is reported to have been felt...." MMI for this location: III ? Location Described: Colusa, Colusa Co. Report 1: Daily Colusa Sun, 13 Aug 1907; p. 4, c. 5 "It is sleepy time at 4 a. m. That is the reason the light shake last Sunday morning was not heard from in all quarters. No one waked up, no damage done." MMI for this location: Not Felt Location Described: Crescent City, Del Norte Co. Report 1: Del Norte Record, 17 Aug 1907; p. 3, c. 1 "Quite a heavy earthquake was felt in Humboldt county last Sunday morning, at an early hour. Del Norter's [sic] felt no quake so far as heard from." MMI for this location: Not Felt Location Described: Willows, Glenn Co. Report 1: Glenn Transcript, 14 Aug 1907; p. 3, c. 2 "We had an earthquake here ... but it was so light that but few people knew that we had such a visitor." Report 2: Willows Review, 16 Aug 1907; p. 3, c. 2 "A slight earthquake shock was felt here.... It lasted for about two seconds but no damage was done." Report 3: Townley and Allen (1939), p. 146 "This shock was ... reported from ... Willows, Glenn Co. ..." This report is credited to U.S. Weather Bureau Form 1009. MMI for this location: III Location Described: Arcata, Humboldt Co. Report 1: Humboldt Times, 13 Aug 1907; p. 2, c. 1-2 "... two [earthquake shocks], a quite hard one and one light one, were felt early in the morning." MMI for this location: Uncertain Location Described: Blocksburg, Humboldt Co. Report 1: Humboldt Times, 13 Aug 1907; p. 7, c. 6 "BLOCKSBURG, Aug. 11.-The people of our little burg were awakened from their slumbers by quite a severe shock of earthquake.... The shock was heavy enough to stop clocks, but otherwise no damage was done." Report 2: Humboldt Standard, 13 Aug 1907; p. 7, c. 7 "Blocksburg, Aug. 11.-At 4:25 a. m. we had quite a shake up, at first gentle and then severe, stopping clocks, etc., etc., and accompanied by a roaring noise. Except for that of the 19th [sic] of April, 1906, it was the most pronounced in 32 years." Report 3: Townley and Allen (1939), p. 146 "At Blocksburg and Covelo clocks stopped." This report is credited to A. H. Bell's manuscript list of earthquakes at Eureka, Calif., 1887 to 1913. MMI for this location: V ? Location Described: Briceland, Humboldt Co. Report 1: Humboldt Times, 15 Aug 1907; p. 8, c. 4-6 "BRICELAND, Aug. 11.... A very heavy earthquake shook things up here at an early hour this morning. It lasted much longer than the two which occurred earlier in the week." MMI for this location: Uncertain Location Described: Cape Mendocino, Humboldt Co. Report 1: Lighthouse Log for Cape Mendocino Lighthouse, 11 Aug 1907 "a light earthquake shock 4.15 a.m." MMI for this location: Uncertain Location Described: Eureka, Humboldt Co. Report 1: Humboldt Standard, 12 Aug 1907; p. 4, c. 7 "Early morning shakes are getting to be a feature of the terrestrial phenomena in these parts of late. Yesterday morning [11 Aug] and again this morning [12 Aug] the people were treated to a rattling of windows and doors. The quake of yesterday morning was quite prolonged but as far as can be learned did no damage in this city...." Report 2: Humboldt Times, 14 Aug 1907; p. 8, c. 4 "A light earthquake shock was felt Sunday morning at 4:19 o'clock in this city and for some distance down the coast. The report of Observer Bell of the local Weather Bureau shows that the shock lasted 15 seconds with the vibrations running from southeast to northwest...." Report 3: Townley and Allen (1939), p. 146 "Quite heavy; southeast to northwest; duration about fifteen seconds; steady shaking." This report is credited to A. H. Bell's manuscript list of earthquakes at Eureka, Calif., 1887 to 1913. MMI for this location: IV Location Described: Falk, Humboldt Co. Report 1: Humboldt Standard, 16 Aug 1907; p. 7, c. 5 "... Another earthquake shock was felt ... but no damage was done." MMI for this location: Uncertain Location Described: Ferndale, Humboldt Co. Report 1: Humboldt Standard, 12 Aug 1907; p. 4, c. 7 "Early morning shakes are getting to be a feature of the terrestrial phenomena in these parts of late. Yesterday morning [11 Aug] and again this morning [12 Aug] the people [of Eureka] were treated to a rattling of windows and doors. The quake of yesterday morning was quite prolonged but as far as can be learned did no damage in this city. At Ferndale it was a little sharper and one of the results was the cracking of the plaster in the Ferndale Bank where the vault is built into a wall. Report 2: Humboldt Standard, 13 Aug 1907; p. 7, c. 6 "Ferndale, August 12-.... Quite a heavy shock of earthquake was felt yesterday morning and another this morning, followed each morning by two lighter ones. No damage reported. There was no sudden jerk such as is usually felt." MMI for this location: V Location Described: Fortuna, Humboldt Co. Report 1: Townley and Allen (1939), p. 146 "This shock was felt at Fortuna, where plaster in bank building became loosened somewhat near safe." This report is credited to A. H. Bell's manuscript list of earthquakes at Eureka, Calif., 1887 to 1913. MMI for this location: V Location Described: Garberville, Humboldt Co. Report 1: Humboldt Times, 14 Aug 1907; p. 6, c. 2-3 "GARBERVILLE, Aug. 11-... a seismic disturbance nearly equal to the long-to-be-remembered one of April 18th last year disturbed the town, the shock lasting some seconds, the rocking motion being perceptible for some time after the first shock...." MMI for this location: Uncertain Location Described: near Reed Mountain (?), Humboldt Co. Report 1: Humboldt Standard, 16 Aug 1907; p. 7, c. 5 "Garberville, August 13-.... Mr. and Mrs. Joe Caton returned yesterday from their hunting trip above the Reed ranges. The morning of the earthquake they were camped on a high ridge and knew nothing of the disturbance at the time." Too much significance should not be placed in the fact that this event was not felt by two particular people who were outdoors and possibly moving about at the time. MMI for this location: Uncertain Location Described: Rocky Glen (?), Humboldt Co. Report 1: Humboldt Standard, 16 Aug 1907; p. 7, c. 5 "Garberville, August 13-.... Mrs. J. E. Sinclair of Rocky Glenn [sic] and daughter Emma were in town today shopping, and inquiring how we fared during the earthquake. The shocks were about the same degree at Rocky Glenn [sic] as here." MMI for this location: Uncertain Location Described: Ryan Slough, Humboldt Co. Report 1: Humboldt Standard, 14 Aug 1907; p. 3, c. 5 "One result of the earthquake shock of early Sunday morning, not hitherto reported, was the throwing down of the smokestack at the McKay & Co.'s shingle mill on Ryan Slough...." MMI for this location: Uncertain Location Described: Branscomb, Mendocino Co. Report 1: Townley and Allen (1939), p. 146 "This shock was ... reported from Branscomb, Mendocino Co. ..." This report is credited to U.S. Weather Bureau Form 1009. MMI for this location: Uncertain Location Described: Covelo, Mendocino Co. Report 1: Humboldt Times, 14 Aug 1907; p. 8, c. 4 "... At Covelo the shock was great enough to stop several of the clocks." Report 2: Townley and Allen (1939), p. 146 "At Blocksburg and Covelo clocks stopped." This report is credited to A. H. Bell's manuscript list of earthquakes at Eureka, Calif., 1887 to 1913. MMI for this location: V ? Location Described: Fort Bragg, Mendocino Co. Report 1: Humboldt Times, 14 Aug 1907; p. 8, c. 4 "The shock was felt at ... Fort Bragg...." Report 2: Townley and Allen (1939), p. 146 "... felt at Fort Bragg and Willits, Mendocino Co." This report is credited to A. H. Bell's manuscript list of earthquakes at Eureka, Calif., 1887 to 1913. MMI for this location: Uncertain Location Described: Laytonville, Mendocino Co. Report 1: Humboldt Times, 14 Aug 1907; p. 8, c. 4 "The shock was felt at Laytonville...." Report 2: Townley and Allen (1939), p. 146 "Laytonville, Mendocino Co., operator reported vibrations from east to west...." This report is credited to A. H. Bell's manuscript list of earthquakes at Eureka, Calif., 1887 to 1913. MMI for this location: Uncertain Location Described: Mendocino, Mendocino Co. Report 1: Mendocino Beacon, 17 Aug 1907; p. 1, c. 1-2 "A sharp shock of earthquake startled some of our people from their slumbers last Sunday morning about 3:40 o'clock. No damage was done, unless it was to some of the more sensitive nerves. In fact the majority of the people did not feel the temblor." Report 2: Mendocino Beacon, 17 Aug 1907; p. 5, c. 2 "A slight seismic disturbance awakened the people of Mendocino from sound slumber last Sunday morning at 4:15. It was of short duration and was not repeated." MMI for this location: IV Location Described: Willits, Mendocino Co. Report 1: Humboldt Times, 14 Aug 1907; p. 8, c. 4 "The shock was felt at ... Willits...." Report 2: Townley and Allen (1939), p. 146 "... felt at Fort Bragg and Willits, Mendocino Co." This report is credited to A. H. Bell's manuscript list of earthquakes at Eureka, Calif., 1887 to 1913. MMI for this location: Uncertain Location Described: French Corral, Nevada Co. Report 1: Daily Morning Union (Grass Valley and Nevada City), 13 Aug 1907; p. 6, c. 3 "... Persons coming in from French Corral and North San Juan yesterday report that the Sunday morning early tremor was felt at those camps...." MMI for this location: Uncertain Location Described: Grass Valley, Nevada Co. Report 1: Sacramento Union, 12 Aug 1907; p. 6, c. 3 "GRASS VALLEY, Aug. 11.-Three distinct shocks of earthquake were felt here this morning at about 3:50 o'clock. Each shock was of about two seconds' duration, and the vibration was from west to east. The disturbance was heavy enough to awaken and frighten a number of people, but no damage has been reported. Some persons report hearing a peculiar rumbling noise preceding and during the continuance of the quakes." MMI for this location: IV Location Described: Nevada City, Nevada Co. Report 1: Daily Morning Union (Grass Valley and Nevada City), 13 Aug 1907; p. 6, c. 3 "A seismic tremor passed through this part of the country Sunday morning about 4 o'clock, sufficiently strong to arouse many persons from their slumbers...." Report 2: Townley and Allen (1939), p. 146 "This shock was ... reported from ... Nevada City, Nevada Co. ..." This report is credited to U.S. Weather Bureau Form 1009. MMI for this location: IV Location Described: North San Juan, Nevada Co. Report 1: Daily Morning Union (Grass Valley and Nevada City), 13 Aug 1907; p. 6, c. 3 "... Persons coming in from French Corral and North San Juan yesterday report that the Sunday morning early tremor was felt at those camps...." MMI for this location: Uncertain Location Described: Shady Creek gravel mine, Nevada Co. Report 1: Daily Morning Union (Grass Valley and Nevada City), 13 Aug 1907; p. 6, c. 3 "... Superintendent Graham of the Shady Creek gravel mine was in Nevada City yesterday and said the trembling was experienced in his camp...." MMI for this location: Uncertain Location Described: La Porte, Plumas Co. Report 1: Townley and Allen (1939), p. 146 "This shock was ... reported from ... La Porte, Plumas Co. ..." This report is credited to U.S. Weather Bureau Form 1009. MMI for this location: Uncertain Location Described: San Francisco, San Francisco Co. Report 1: Humboldt Standard, 12 Aug 1907; p. 4, c. 7 "... Report from San Francisco this morning was to the effect that it was scarcely noticeable there." From the context, it is not completely clear whether the report from San Francisco refers to the event on 11 Aug or to another event (on 12 Aug) which was also mentioned in the article. Report 2: Humboldt Times, 13 Aug 1907; p. 3, c. 1 "No great earthquake shock was felt in San Francisco Sunday morning as was reported on the streets here yesterday. People incoming by the steamers from San Francisco yesterday stated that the shock was very light and nothing more than usual, for tremors are still a common occurrence in the metropolis." MMI for this location: II Location Described: Baird, Shasta Co. Report 1: The Searchlight (Redding), 13 Aug 1907; p. 1, c. 3-4 "BAIRD, August 12.-A sharp earthquake shock was felt here at 4:30 yesterday morning. All persons in camp along the [McCloud] river felt it, but the severest shock was undoubtedly at the McCloud fishery. Captain Lambson, superintendent of the fishery, awakened by the earthquake, looked at his watch immediately. It was 4:30 according to his time. It was a distant and sharp shock at first, dying away in gentle quivers whose duration was from eight to ten seconds." Report 2: The Searchlight (Redding), 13 Aug 1907; p. 1, c. 3-4 "Sunday's earthquake was felt generally all over the Sacramento Valley, but seems to have been most pronounced at the McCloud fishery [on McCloud River, near Baird (?)]. Adolph Dobrowsky, who was camping out near the fishery, was awake when the shock occurred and noted the time and duration. It was 4:30 and lasted about ten seconds." MMI for this location: V Location Described: Redding, Shasta Co. Report 1: The Searchlight (Redding), 13 Aug 1907; p. 1, c. 3-4 "In Redding many were awakened from their early morning's sleep. In private houses and in all-night restaurants the rattling of dishes and cooking utensils proclaimed the sharpness of the seismic disturbance. It was noticeable on the road by the drivers of a few vehicles. "The shock was well defined, starting at about 4:30 and lasting not more than ten seconds. No reports have been received of the breaking of even the lightest articles on bureaus and mantels, however, and most healthy sleepers slept right through the shock." MMI for this location: IV Location Described: Sisson, Siskiyou Co. (now the town of Mt. Shasta, CA) Report 1: The Searchlight (Redding), 13 Aug 1907; p. 1, c. 3-4 "SISSON, August 12.-This place was disturbed yesterday morning by a temblor which startled those who felt it and frightened a few, though the earthquake was slight and lasted but a few seconds. It came at 4:30 a. m." MMI for this location: IV Location Described: Corning, Tehama Co. Report 1: Corning Observer, 15 Aug 1907; p. 1, c. 2 "About four o'clock Sunday morning those of us who were awake were startled by a short series of earthquake shocks. The vibrations seemed to be from east to west and the doors and windows rattled for about thirty seconds. Aside from curiosity and a slight alarm among a few the shock did not create much comment...." MMI for this location: IV Location Described: Red Bluff, Tehama Co. Report 1: Weekly People's Cause (Red Bluff), 17 Aug 1907; p. 8, c. 3 "A portion of Red Bluff's population was furnished with some excitement early Sunday morning that all did* share. The reason that all did not share in the excitement was that some of the people were sleeping too soundly. "At about 4 o'clock Sunday morning Red Bluff was visited by an earthquake that made the doors and windows of many of the houses rattle.... "No harm resulted from the earthquake, the vibrations only being of a few seconds duration." * Compare this article with similar articles that appeared in the Courier-Free Press and the Searchlight, both of Redding. The latter two articles were presumably copied from the Daily People's Cause (the daily version of this paper, which could not be located for 1907). In the two Redding papers, the word "not" appears at the place marked by an asterisk above; in this article, however, the word "not" does not appear at that location. Based on the inconsistency, and from the context, it appears that this was an accidental typographical omission. It is inferred that the line was intended to read "... excitement early Sunday morning that all did not share." Report 2: Courier-Free Press (Redding), 13 Aug 1907; p. 7, c. 1 "RED BLUFF, Aug. 18*-A portion of Red Bluff's population was furnished with some excitement early Sunday morning that all did not share. The reason that all did not share in the excitement was that some of the people were sleeping too soundly. "At about 4 o'clock Sunday morning Red Bluff was visited by an earthquake that made the doors and windows of many of the houses rattle.... "No harm resulted from the earthquake, the vibrations only being of a few seconds duration." * The dateline is clearly incorrect; it should be either Aug. 12 or 13. Report 3: The Searchlight (Redding), 14 Aug 1907; p. 6, c. 2 "Red Bluff was furnished with some excitement early Sunday morning in which all did not share. The reason that all did not share in the excitement was that some of the people were sleeping too soundly, says the Cause. "At about 4 o'clock Sunday morning Red Bluff was visited by an earthquake that made the doors and windows of many of the houses rattle.... "No harm resulted from the earthquake, the vibrations only being of a few seconds duration." MMI for this location: IV Location Described: Island Mountain, Trinity Co. Report 1: Humboldt Standard, 17 Aug 1907; p. 5, c. 5 "Island Mountain, Aug. 12-.... Saturday morning at 4 o'clock the people of the island were awakened by a heavy earthquake." The reported date of this event, Saturday, 10 Aug 1907, is almost certainly incorrect, as it is described here as heavy, but no other locality reported an event on this date; it is probably the 11 Aug event. MMI for this location: Uncertain Location Described: Ruth, Trinity Co. Report 1: Humboldt Standard, 27 Aug 1907; p. 7, c. 7 "Ruth, Trinity Co., August 23-.... We know that Mother Earth is very uneasy for the temblors of the 9th, 11th, and 12th insts. were quite hard, but the one on the 18th at 3:20 p. m. was the most severe...." MMI for this location: Uncertain Location Described: Weaverville, Trinity Co. Report 1: Weekly Trinity Journal, 17 Aug 1907; p. 3, c. 6 "An earthquake shock was felt by a number of our citizens on Sunday morning about 4:30. No damage done." Report 2: Courier-Free Press (Redding), 14 Aug 1907; p. 7, c. 3 "WEAVERVILLE, Aug. 14.-.... The earthquake Sunday morning at 4:30 was plainly felt by several of our citizens." MMI for this location: IV ? Other Information: Instrumental Data Report 1: Townley and Allen (1939), p. 146 "This shock ... made a decided record on the seismograph at Berkeley, and seems to have registered on a number of distant seismographs, the most distant being that at Tiflis [now Tbilisi, the capital of the Republic of Georgia]." This report is credited to the Strassburg [Strasbourg?] catalog of teleseisms recorded during 1907. MMI for this location: N/A