This paper describes a direct comparison of apparent ages derived from 3H/3He, chlorofluorocarbons (CCl3F and CCl2F2), and 85Kr measurements in shallow groundwater. Wells chosen for this study are completed in the unconfined surficial aquifers in late Cenozoic Atlantic Coastal Plain sediments of the Delmarva Peninsula, on the east coast of the United States. Most of the apparent tracer ages agree within 2 years of each other for recharge dates between 1965 and 1990. Discrepancies in apparent tracer ages usually can be explained by hydrological processes such as mixing in a discharge area. Recharge rate calculations based on apparent tracer age gradients at multilevel well locations agree with previous recharge estimates. High recharge rates on the Delmarva Peninsula result in nearly complete dissolved-gas confinement in the groundwater. The remarkable agreement between the different tracer ages indicates negligible mixing of waters of different ages, insignificant dispersion, minimal gas loss to the atmosphere, and insignificant sorption-desorption processes at this location.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/94WR00156","usgsCitation":"Ekwurzel, B., Schlosser, P., Smethie, W.M., Plummer, N., Busenberg, E., Michel, R.L., Weppernig, R., and Stute, M., 1994, Dating of shallow groundwater: Comparison of the transient tracers 3H/3He, chlorofluorocarbons, and 85Kr: Water Resources Research, v. 30, no. 6, p. 1693-1708, https://doi.org/10.1029/94WR00156.","productDescription":"16 p. ","startPage":"1693","endPage":"1708","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":337954,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"30","issue":"6","noUsgsAuthors":false,"publicationDate":"2010-07-09","publicationStatus":"PW","scienceBaseUri":"58d23b97e4b0236b68f82978","contributors":{"authors":[{"text":"Ekwurzel, Brenda","contributorId":189618,"corporation":false,"usgs":false,"family":"Ekwurzel","given":"Brenda","email":"","affiliations":[],"preferred":false,"id":685420,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Schlosser, Peter","contributorId":50936,"corporation":false,"usgs":true,"family":"Schlosser","given":"Peter","email":"","affiliations":[],"preferred":false,"id":685421,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Smethie, William M. Jr.","contributorId":189619,"corporation":false,"usgs":false,"family":"Smethie","given":"William","suffix":"Jr.","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":685422,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Plummer, Niel 0000-0002-4020-1013 nplummer@usgs.gov","orcid":"https://orcid.org/0000-0002-4020-1013","contributorId":190100,"corporation":false,"usgs":true,"family":"Plummer","given":"Niel","email":"nplummer@usgs.gov","affiliations":[{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true}],"preferred":true,"id":685423,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Busenberg, Eurybiades ebusenbe@usgs.gov","contributorId":2271,"corporation":false,"usgs":true,"family":"Busenberg","given":"Eurybiades","email":"ebusenbe@usgs.gov","affiliations":[{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true}],"preferred":true,"id":685424,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Michel, Robert L. rlmichel@usgs.gov","contributorId":823,"corporation":false,"usgs":true,"family":"Michel","given":"Robert","email":"rlmichel@usgs.gov","middleInitial":"L.","affiliations":[{"id":148,"text":"Branch of Regional Research-Western Region","active":false,"usgs":true}],"preferred":true,"id":685425,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Weppernig, Ralf","contributorId":189620,"corporation":false,"usgs":false,"family":"Weppernig","given":"Ralf","email":"","affiliations":[],"preferred":false,"id":685426,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Stute, Martin","contributorId":131127,"corporation":false,"usgs":false,"family":"Stute","given":"Martin","email":"","affiliations":[{"id":7254,"text":"Columbia University - Lamont Doherty Earth Observatory","active":true,"usgs":false}],"preferred":false,"id":685427,"contributorType":{"id":1,"text":"Authors"},"rank":8}]}} ,{"id":70186590,"text":"70186590 - 1994 - The co-seismic slip distribution of the Landers earthquake","interactions":[],"lastModifiedDate":"2023-10-24T11:05:10.69335","indexId":"70186590","displayToPublicDate":"1994-06-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1135,"text":"Bulletin of the Seismological Society of America","onlineIssn":"1943-3573","printIssn":"0037-1106","active":true,"publicationSubtype":{"id":10}},"title":"The co-seismic slip distribution of the Landers earthquake","docAbstract":"We derived a model for the co-seismic slip distribution on the faults which ruptured during the Landers earthquake sequence of 28 June 1992. The model is based on the inversion of surface geodetic measurements, primarily vector displacements measured using the Global Positioning System (GPS). The inversion procedure assumes that the slip distribution is to some extent smooth and purely right-lateral strike slip. For a given fault geometry, a family of solutions of varying smoothness can be generated.
We choose the optimal model from this family based on cross-validation, which measures the predictive power of the data, and the trade-off of misfit and roughness. Solutions which give roughly equal weight to misfit and smoothness are preferred and have certain features in common: (1) there are two main patches of slip, on the Johnson Valley fault, and on the Homestead Valley, Emerson, and Camp Rock faults; (2) virtually all slip is in the upper 10 to 12 km; and (3) the model reproduces the general features of the geologically measured surface displacements, without prior constraints on the surface slip. In all models, regardless of smoothing, very little slip is required on the fault that represents the Big Bear event, and the total moment of the Landers event is 9 · 1019 N-m. The nearly simultaneous rupture of multiple distinct faults suggests that much of the crust in this region must have been close to failure prior to the earthquake.
","language":"English","publisher":"Seismological Society of America","doi":"10.1785/BSSA0840030646","usgsCitation":"Freymueller, J., King, N., and Segall, P., 1994, The co-seismic slip distribution of the Landers earthquake: Bulletin of the Seismological Society of America, v. 84, no. 3, p. 646-659, https://doi.org/10.1785/BSSA0840030646.","productDescription":"14 p.","startPage":"646","endPage":"659","costCenters":[],"links":[{"id":339264,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -117.48148758019548,\n 35.175884043309324\n ],\n [\n -117.48148758019548,\n 33.55266747577443\n ],\n [\n -115.32816726769562,\n 33.55266747577443\n ],\n [\n -115.32816726769562,\n 35.175884043309324\n ],\n [\n -117.48148758019548,\n 35.175884043309324\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"84","issue":"3","noUsgsAuthors":false,"publicationDate":"1994-06-01","publicationStatus":"PW","scienceBaseUri":"58e60277e4b09da6799ac6a5","contributors":{"authors":[{"text":"Freymueller, J.","contributorId":190583,"corporation":false,"usgs":false,"family":"Freymueller","given":"J.","affiliations":[],"preferred":false,"id":689665,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"King, N.E.","contributorId":29950,"corporation":false,"usgs":true,"family":"King","given":"N.E.","email":"","affiliations":[],"preferred":false,"id":689666,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Segall, P.","contributorId":44231,"corporation":false,"usgs":false,"family":"Segall","given":"P.","affiliations":[],"preferred":false,"id":689667,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70186725,"text":"70186725 - 1994 - Shear zones formed along long, straight traces of fault zones during the 28 June 1992 Landers, California, earthquake","interactions":[],"lastModifiedDate":"2023-10-24T01:26:59.600239","indexId":"70186725","displayToPublicDate":"1994-06-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1135,"text":"Bulletin of the Seismological Society of America","onlineIssn":"1943-3573","printIssn":"0037-1106","active":true,"publicationSubtype":{"id":10}},"title":"Shear zones formed along long, straight traces of fault zones during the 28 June 1992 Landers, California, earthquake","docAbstract":"Surface rupturing during the 28 June 1992 Landers, California, earthquake, east of Los Angeles, accommodated right-lateral offsets up to about 6 m along segments of distinct, en-echelon fault zones with a total length of 80 km. The offsets were accommodated generally not by faults—distinct slip surfaces—but rather by shear zones, tabular bands of localized shearing. Along simple stretches of fault zones at Landers the rupture is characterized by telescoping of shear zones and intensification of shearing: broad shear zones of mild shearing, containing narrow shear zones of more intense shearing, containing even narrower shear zones of very intense shearing, which may contain a fault. Thus the ground ruptured across broad belts of shearing with clearly defined, subparallel walls, oriented NW. Each broad belt consists of a broad zone of mild shearing, extending across its entire width (50 to 200 m), and much narrower (a few meters wide) shear zones that accommodate most of the offset of the belt and are portrayed by en-echelon tension cracks. In response to right-lateral shearing, the slices of ground bounded by the tension cracks rotated in a clockwise sense, producing left-lateral shearing, and the slices were forced against the walls of the shear zone, producing thrusting. Even narrower shear zones formed within the narrow shear zones. Although these probably are guides to right-lateral fault segments below, the surface rupturing during the earthquake is characterized not by faulting, but by the formation of shear zones at various scales.
","language":"English","publisher":"Seismological Society of America","doi":"10.1785/BSSA0840030499","usgsCitation":"Johnson, A.M., Fleming, R.W., and Cruikshank, K.M., 1994, Shear zones formed along long, straight traces of fault zones during the 28 June 1992 Landers, California, earthquake: Bulletin of the Seismological Society of America, v. 84, no. 3, p. 499-510, https://doi.org/10.1785/BSSA0840030499.","productDescription":"12 p.","startPage":"499","endPage":"510","costCenters":[],"links":[{"id":339455,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","volume":"84","issue":"3","noUsgsAuthors":false,"publicationDate":"1994-06-01","publicationStatus":"PW","scienceBaseUri":"58e8a549e4b09da6799d63d5","contributors":{"authors":[{"text":"Johnson, Arvid M.","contributorId":99547,"corporation":false,"usgs":true,"family":"Johnson","given":"Arvid","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":690368,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Fleming, Robert W.","contributorId":102062,"corporation":false,"usgs":true,"family":"Fleming","given":"Robert","email":"","middleInitial":"W.","affiliations":[],"preferred":false,"id":690369,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Cruikshank, Kenneth M.","contributorId":190691,"corporation":false,"usgs":false,"family":"Cruikshank","given":"Kenneth","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":690370,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70180353,"text":"70180353 - 1994 - Pen rearing and imprinting of fall Chinook salmon","interactions":[],"lastModifiedDate":"2017-01-27T13:54:11","indexId":"70180353","displayToPublicDate":"1994-06-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":4,"text":"Other Government Series"},"title":"Pen rearing and imprinting of fall Chinook salmon","docAbstract":"Results of rearing upriver bright fall chinook salmon juveniles in net pens and a barrier net enclosure in two backwater areas and a pond along the Columbia River were compared with traditional hatchery methods. Growth, smoltification, and general condition of pen-reared fish receiving supplemental feeding were better than those of fish reared using traditional methods. Juvenile fish receiving no supplemental feeding were generally in poor condition resulting in a net loss of production. Rearing costs using pens were generally lower than in the hatchery. However, low adult returns resulted in greater cost per adult recovery than fish reared and released using traditional methods. Much of the differences in recovery rates may have been due to differences in rearing locations, as study sites were as much as 128 mi upstream from the hatcheries and study fish may have incurred higher mortality associated with downstream migration than control fish. Fish reared using these methods could be a cost-effective method of enhancing salmon production in the Columbia River Basin.
","language":"English","publisher":"Bonneville Power Administration","usgsCitation":"Beeman, J., and Novotny, J., 1994, Pen rearing and imprinting of fall Chinook salmon, iv., 28 p. .","productDescription":"iv., 28 p. ","costCenters":[{"id":654,"text":"Western Fisheries Research Center","active":true,"usgs":true}],"links":[{"id":334209,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":334207,"rank":1,"type":{"id":11,"text":"Document"},"url":"https://pisces.bpa.gov/release/documents/DocumentViewer.aspx?doc=13084-6"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"588c6aa8e4b08c8121c90976","contributors":{"authors":[{"text":"Beeman, J.W.","contributorId":32646,"corporation":false,"usgs":true,"family":"Beeman","given":"J.W.","email":"","affiliations":[],"preferred":false,"id":661345,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Novotny, J.F.","contributorId":95856,"corporation":false,"usgs":true,"family":"Novotny","given":"J.F.","email":"","affiliations":[],"preferred":false,"id":661346,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70186738,"text":"70186738 - 1994 - Magnetic field observations in the near-field the 28 June 1992 Mw 7.3 Landers, California, earthquake","interactions":[],"lastModifiedDate":"2023-10-24T01:15:51.116012","indexId":"70186738","displayToPublicDate":"1994-06-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1135,"text":"Bulletin of the Seismological Society of America","onlineIssn":"1943-3573","printIssn":"0037-1106","active":true,"publicationSubtype":{"id":10}},"title":"Magnetic field observations in the near-field the 28 June 1992 Mw 7.3 Landers, California, earthquake","docAbstract":"Recent reports suggest that large magnetic field changes occur prior to, and during, large earthquakes. Two continuously operating proton magnetometers, LSBM and OCHM, at distances of 17.3 and 24.2 km, respectively, from the epicenter of the 28 June 1992 Mw 7.3 Landers earthquake, recorded data through the earthquake and its aftershocks. These two stations are part of a differentially connected array of proton magnetometers that has been operated along the San Andreas fault since 1976. The instruments have a sensitivity of 0.25 nT or better and transmit data every 10 min through the GOES satellite to the USGS headquarters in Menlo Park, California. Seismomagnetic offsets of −1.2 ± 0.6 and −0.7 ± 0.7 nT were observed at these sites. In comparison, offsets of −0.3 ± 0.2 and −1.3 ± 0.2 nT were observed during the 8 July 1986 ML 5.9 North Palm Springs earthquake, which occurred directly beneath the OCHM magnetometer site. The observations are generally consistent with seismomagnetic models of the earthquake, in which fault geometry and slip have the same from as that determined by either inversion of the seismic data or inversion of geodetically determined ground displacements produced by the earthquake. In these models, right-lateral rupture occurs on connected fault segments in a homogeneous medium with average magnetization of 2 A/m. The fault-slip distribution has roughly the same form as the observed surface rupture, and the total moment release is 1.1 × 1020 Nm. There is no indication of diffusion-like character to the magnetic field offsets that might indicate these effects result from fluid flow phenomena. It thus seems unlikely that these earthquake-generated offsets and those produced by the North Palm Springs earthquake were generated by electrokinetic effects. Also, there are no indications of enhanced low-frequency magnetic noise before the earthquake at frequencies below 0.001 Hz.
","language":"English","publisher":"Seismological Society of America","doi":"10.1785/BSSA0840030792","usgsCitation":"Johnston, M.J., Mueller, R., and Sasai, Y., 1994, Magnetic field observations in the near-field the 28 June 1992 Mw 7.3 Landers, California, earthquake: Bulletin of the Seismological Society of America, v. 84, no. 3, p. 792-798, https://doi.org/10.1785/BSSA0840030792.","productDescription":"7 p.","startPage":"792","endPage":"798","costCenters":[],"links":[{"id":339474,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -117.48148758019548,\n 35.175884043309324\n ],\n [\n -117.48148758019548,\n 33.55266747577443\n ],\n [\n -115.32816726769562,\n 33.55266747577443\n ],\n [\n -115.32816726769562,\n 35.175884043309324\n ],\n [\n -117.48148758019548,\n 35.175884043309324\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"84","issue":"3","noUsgsAuthors":false,"publicationDate":"1994-06-01","publicationStatus":"PW","scienceBaseUri":"58e8a549e4b09da6799d63cf","contributors":{"authors":[{"text":"Johnston, M. J.","contributorId":64255,"corporation":false,"usgs":true,"family":"Johnston","given":"M.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":690417,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Mueller, R.J.","contributorId":77135,"corporation":false,"usgs":true,"family":"Mueller","given":"R.J.","email":"","affiliations":[],"preferred":false,"id":690418,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Sasai, Yoichi","contributorId":190700,"corporation":false,"usgs":false,"family":"Sasai","given":"Yoichi","email":"","affiliations":[],"preferred":false,"id":690419,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70186195,"text":"70186195 - 1994 - Local observations of the onset of a large earthquake: 28 June 1992 Landers, California","interactions":[],"lastModifiedDate":"2023-10-25T11:19:02.509054","indexId":"70186195","displayToPublicDate":"1994-06-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1135,"text":"Bulletin of the Seismological Society of America","onlineIssn":"1943-3573","printIssn":"0037-1106","active":true,"publicationSubtype":{"id":10}},"title":"Local observations of the onset of a large earthquake: 28 June 1992 Landers, California","docAbstract":"The Landers earthquake (MW 7.3) of 28 June 1992 had a very emergent onset. The first large amplitude arrivals are delayed by about 3 sec with respect to the origin time, and are preceded by smaller-scale slip. Other large earthquakes have been observed to have similar emergent onsets, but the Landers event is one of the first to be well recorded on nearby stations. We used these recordings to investigate the spatial relationship between the hypocenter and the onset of the large energy release, and to determine the slip function of the 3-sec nucleation process. Relative location of the onset of the large energy release with respect to the initial hypocenter indicates its source was between 1 and 4 km north of the hypocenter and delayed by approximately 2.5 sec. Three-station array analysis of the P wave shows that the large amplitude onset arrives with a faster apparent velocity compared to the first arrivals, indicating that the large amplitude source was several kilometers deeper than the initial onset. An ML 2.8 foreshock, located close to the hypocenter, was used as an empirical Green's function to correct for path and site effects from the first 3 sec of the mainshock seismogram. The resultant deconvolution produced a slip function that showed two subevents preceding the main energy release, an MW4.4 followed by an MW 5.6. These subevents do not appear anomalous in comparison to simple moderate-sized earthquakes, suggesting that they were normal events which just triggered or grew into a much larger earthquake. If small and moderate-sized earthquakes commonly “detonate” much larger events, this implies that the dynamic stresses during earthquake rupture are at least as important as long-term static stresses in causing earthquakes, and the prospects of reliable earthquake prediction from premonitory phenomena are not improved.
","language":"English","publisher":"Seismological Society of America","doi":"10.1785/BSSA0840030725","usgsCitation":"Abercrombie, R., and Mori, J., 1994, Local observations of the onset of a large earthquake: 28 June 1992 Landers, California: Bulletin of the Seismological Society of America, v. 84, no. 3, p. 725-734, https://doi.org/10.1785/BSSA0840030725.","productDescription":"10 p.","startPage":"725","endPage":"734","costCenters":[],"links":[{"id":338951,"rank":2,"type":{"id":15,"text":"Index Page"},"url":"https://pubs.geoscienceworld.org/ssa/bssa/article/84/3/725/102652/Local-observations-of-the-onset-of-a-large"},{"id":338952,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","city":"Landers","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -116.4997100830078,\n 34.175453097578526\n ],\n [\n -116.26487731933592,\n 34.175453097578526\n ],\n [\n -116.26487731933592,\n 34.326993104644515\n ],\n [\n -116.4997100830078,\n 34.326993104644515\n ],\n [\n -116.4997100830078,\n 34.175453097578526\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"84","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"58df6ac9e4b02ff32c6aea83","contributors":{"authors":[{"text":"Abercrombie, Richael","contributorId":190227,"corporation":false,"usgs":false,"family":"Abercrombie","given":"Richael","email":"","affiliations":[],"preferred":false,"id":687847,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Mori, Jim","contributorId":55840,"corporation":false,"usgs":true,"family":"Mori","given":"Jim","affiliations":[],"preferred":false,"id":687848,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70186737,"text":"70186737 - 1994 - Continuous borehole strain in the San Andreas fault zone before, during, and after the 28 June 1992, MW 7.3 Landers, California, earthquake","interactions":[],"lastModifiedDate":"2023-10-25T11:03:49.236269","indexId":"70186737","displayToPublicDate":"1994-06-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1135,"text":"Bulletin of the Seismological Society of America","onlineIssn":"1943-3573","printIssn":"0037-1106","active":true,"publicationSubtype":{"id":10}},"title":"Continuous borehole strain in the San Andreas fault zone before, during, and after the 28 June 1992, MW 7.3 Landers, California, earthquake","docAbstract":"High-precision strain was observed with a borehole dilational strainmeter in the Devil's Punchbowl during the 11:58 UT 28 June 1992 MW 7.3 Landers earthquake and the large Big Bear aftershock (MW 6.3). The strainmeter is installed at a depth of 176 m in the fault zone approximately midway between the surface traces of the San Andreas and Punchbowl faults and is about 100 km from the 85-km-long Landers rupture. We have questioned whether unusual amplified strains indicating precursive slip or high fault compliance occurred on the faults ruptured by the Landers earthquake, or in the San Andreas fault zone before and during the earthquake, whether static offsets for both the Landers and Big Bear earthquakes agree with expectation from geodetic and seismologic models of the ruptures and with observations from a nearby two-color geodimeter network, and whether postseismic behavior indicated continued slip on the Landers rupture or local triggered slip on the San Andreas. We show that the strain observed during the earthquake at this instrument shows no apparent amplification effects. There are no indications of precursive strain in these strain data due to either local slip on the San Andreas or precursive slip on the eventual Landers rupture. The observations are generally consistent with models of the earthquake in which fault geometry and slip have the same form as that determined by either inversion of the seismic data or inversion of geodetically determined ground displacements produced by the earthquake. Finally, there are some indications of minor postseismic behavior, particularly during the month following the earthquake.
","language":"English","publisher":"Seismological Society of America","doi":"10.1785/BSSA0840030799","usgsCitation":"Johnston, M., Linde, A.T., and Agnew, D., 1994, Continuous borehole strain in the San Andreas fault zone before, during, and after the 28 June 1992, MW 7.3 Landers, California, earthquake: Bulletin of the Seismological Society of America, v. 84, no. 3, p. 799-805, https://doi.org/10.1785/BSSA0840030799.","productDescription":"7 p.","startPage":"799","endPage":"805","costCenters":[],"links":[{"id":339472,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -117.48148758019548,\n 35.175884043309324\n ],\n [\n -117.48148758019548,\n 33.55266747577443\n ],\n [\n -115.32816726769562,\n 33.55266747577443\n ],\n [\n -115.32816726769562,\n 35.175884043309324\n ],\n [\n -117.48148758019548,\n 35.175884043309324\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"84","issue":"3","noUsgsAuthors":false,"publicationDate":"1994-06-01","publicationStatus":"PW","scienceBaseUri":"58e8a549e4b09da6799d63d1","contributors":{"authors":[{"text":"Johnston, M.J.S. 0000-0003-4326-8368","orcid":"https://orcid.org/0000-0003-4326-8368","contributorId":104889,"corporation":false,"usgs":true,"family":"Johnston","given":"M.J.S.","affiliations":[],"preferred":false,"id":690414,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Linde, A. T.","contributorId":21700,"corporation":false,"usgs":true,"family":"Linde","given":"A.","email":"","middleInitial":"T.","affiliations":[],"preferred":false,"id":690415,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Agnew, D.C.","contributorId":32186,"corporation":false,"usgs":true,"family":"Agnew","given":"D.C.","email":"","affiliations":[],"preferred":false,"id":690416,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70186689,"text":"70186689 - 1994 - Southern surface rupture associated with the M 7.3 1992 Landers, California, earthquake","interactions":[],"lastModifiedDate":"2023-10-25T11:06:04.893321","indexId":"70186689","displayToPublicDate":"1994-06-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1135,"text":"Bulletin of the Seismological Society of America","onlineIssn":"1943-3573","printIssn":"0037-1106","active":true,"publicationSubtype":{"id":10}},"title":"Southern surface rupture associated with the M 7.3 1992 Landers, California, earthquake","docAbstract":"Although most evidence suggests that the 28 June 1992 M 7.3 Landers earthquake ruptured unilaterally north, significant surface rupture was mapped on the Eureka Peak and Burnt Mountain faults, to the south of the Landers epicenter. An eyewitness account reports that surface rupture occurred on the northern Eureka Peak fault within approximately 35 sec of the mainshock initiation. Array analysis of the Landers mainshock provides evidence in support of this report; a significant southern subevent in the early mainshock coda. I also analyze dense array recordings of a M 5.6 aftershock that occurred 3 min after the mainshock at 34°7.65′N, 116°23.82′W and show that there is strong evidence that this event was also associated with significant rupture on the Eureka Peak fault. This analysis thus suggests that the Eureka Peak fault rupture was not caused by direct bilateral mainshock rupture but instead was initially triggered less than a minute after the mainshock and reruptured by the M 5.6 aftershock. Results for the evolution of the Landers sequence suggest that mainshock subevents may in some cases be accurately described as aftershocks (i.e., disjoint triggered events) that occur within the duration of mainshock strong ground motion.
","language":"English","publisher":"Seismological Society of America","usgsCitation":"Hough, S., 1994, Southern surface rupture associated with the M 7.3 1992 Landers, California, earthquake: Bulletin of the Seismological Society of America, v. 84, no. 3, p. 817-825.","productDescription":"9 p.","startPage":"817","endPage":"825","costCenters":[],"links":[{"id":339401,"rank":2,"type":{"id":15,"text":"Index Page"},"url":"https://www.bssaonline.org/content/84/3/817.abstract"},{"id":339402,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -117.48148758019548,\n 35.175884043309324\n ],\n [\n -117.48148758019548,\n 33.55266747577443\n ],\n [\n -115.32816726769562,\n 33.55266747577443\n ],\n [\n -115.32816726769562,\n 35.175884043309324\n ],\n [\n -117.48148758019548,\n 35.175884043309324\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"84","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"58e8a549e4b09da6799d63d9","contributors":{"authors":[{"text":"Hough, S. E. 0000-0002-5980-2986","orcid":"https://orcid.org/0000-0002-5980-2986","contributorId":7316,"corporation":false,"usgs":true,"family":"Hough","given":"S. E.","affiliations":[],"preferred":false,"id":690289,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70186690,"text":"70186690 - 1994 - Fault-zone waves observed at the southern Joshua Tree earthquake rupture zone","interactions":[],"lastModifiedDate":"2017-04-07T10:37:25","indexId":"70186690","displayToPublicDate":"1994-06-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1135,"text":"Bulletin of the Seismological Society of America","onlineIssn":"1943-3573","printIssn":"0037-1106","active":true,"publicationSubtype":{"id":10}},"title":"Fault-zone waves observed at the southern Joshua Tree earthquake rupture zone","docAbstract":"Waveform and spectral characteristics of several aftershocks of the M 6.1 22 April 1992 Joshua Tree earthquake recorded at stations just north of the Indio Hills in the Coachella Valley can be interpreted in terms of waves propagating within narrow, low-velocity, high-attenuation, vertical zones. Evidence for our interpretation consists of: (1) emergent P arrivals prior to and opposite in polarity to the impulsive direct phase; these arrivals can be modeled as headwaves indicative of a transfault velocity contrast; (2) spectral peaks in the S wave train that can be interpreted as internally reflected, low-velocity fault-zone wave energy; and (3) spatial selectivity of event-station pairs at which these data are observed, suggesting a long, narrow geologic structure. The observed waveforms are modeled using the analytical solution of Ben-Zion and Aki (1990) for a plane-parallel layered fault-zone structure. Synthetic waveform fits to the observed data indicate the presence of NS-trending vertical fault-zone layers characterized by a thickness of 50 to 100 m, a velocity decrease of 10 to 15% relative to the surrounding rock, and a P-wave quality factor in the range 25 to 50.
","language":"English","publisher":"Seismological Society of America","usgsCitation":"Hough, S., Ben-Zion, Y., and Leary, P., 1994, Fault-zone waves observed at the southern Joshua Tree earthquake rupture zone: Bulletin of the Seismological Society of America, v. 84, no. 3, p. 761-767.","productDescription":"7 p. ","startPage":"761","endPage":"767","costCenters":[],"links":[{"id":339404,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"84","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"58e8a549e4b09da6799d63d7","contributors":{"authors":[{"text":"Hough, S. E. 0000-0002-5980-2986","orcid":"https://orcid.org/0000-0002-5980-2986","contributorId":7316,"corporation":false,"usgs":true,"family":"Hough","given":"S. E.","affiliations":[],"preferred":false,"id":690290,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ben-Zion, Y.","contributorId":190673,"corporation":false,"usgs":false,"family":"Ben-Zion","given":"Y.","affiliations":[],"preferred":false,"id":690291,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Leary, P.","contributorId":190672,"corporation":false,"usgs":false,"family":"Leary","given":"P.","email":"","affiliations":[],"preferred":false,"id":690292,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70185723,"text":"70185723 - 1994 - Microbial transformation of nitroaromatics in surface soils and aquifer materials","interactions":[],"lastModifiedDate":"2023-01-20T14:58:13.060524","indexId":"70185723","displayToPublicDate":"1994-06-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":850,"text":"Applied and Environmental Microbiology","active":true,"publicationSubtype":{"id":10}},"title":"Microbial transformation of nitroaromatics in surface soils and aquifer materials","docAbstract":"Microorganisms indigenous to surface soils and aquifer materials collected at a munitions-contaminated site transformed 2,4,6-trinitrotoluene (TNT), 2,4-dinitrotoluene (2,4-DNT), and 2,6-dinitrotoluene (2,6-DNT) to amino-nitro intermediates within 20 to 70 days. Carbon mineralization studies with both unlabeled (TNT, 2,4-DNT, and 2,6-DNT) and radiolabeled ([14C]TNT) substrates indicated that a significant fraction of these source compounds was degraded to CO2.
","language":"English","publisher":"American Society for Microbiology","doi":"10.1128/aem.60.6.2170-2175.1994","usgsCitation":"Bradley, P., Chapelle, F.H., Landmeyer, J., and Schumacher, J., 1994, Microbial transformation of nitroaromatics in surface soils and aquifer materials: Applied and Environmental Microbiology, v. 60, no. 6, p. 2170-2175, https://doi.org/10.1128/aem.60.6.2170-2175.1994.","productDescription":"6 p.","startPage":"2170","endPage":"2175","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":479330,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://www.ncbi.nlm.nih.gov/pmc/articles/201620","text":"Publisher Index Page"},{"id":338463,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Missouri","city":"Weldon Spring","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -90.73698354073991,\n 38.7467591076545\n ],\n [\n -90.73698354073991,\n 38.67288047585902\n ],\n [\n -90.56205991061313,\n 38.67288047585902\n ],\n [\n -90.56205991061313,\n 38.7467591076545\n ],\n [\n -90.73698354073991,\n 38.7467591076545\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"60","issue":"6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"58db7637e4b0ee37af29e4d4","contributors":{"authors":[{"text":"Bradley, P. M. 0000-0001-7522-8606","orcid":"https://orcid.org/0000-0001-7522-8606","contributorId":29465,"corporation":false,"usgs":true,"family":"Bradley","given":"P. M.","affiliations":[],"preferred":false,"id":686543,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Chapelle, F. H.","contributorId":101697,"corporation":false,"usgs":true,"family":"Chapelle","given":"F.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":686544,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Landmeyer, J. E.","contributorId":91140,"corporation":false,"usgs":true,"family":"Landmeyer","given":"J. E.","affiliations":[],"preferred":false,"id":686545,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Schumacher, J.G.","contributorId":54398,"corporation":false,"usgs":true,"family":"Schumacher","given":"J.G.","email":"","affiliations":[],"preferred":false,"id":686546,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70186728,"text":"70186728 - 1994 - Extremal bounds on earthquake movement from geodetic data: Application to the Landers earthquake","interactions":[],"lastModifiedDate":"2023-10-24T01:22:27.129112","indexId":"70186728","displayToPublicDate":"1994-06-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1135,"text":"Bulletin of the Seismological Society of America","onlineIssn":"1943-3573","printIssn":"0037-1106","active":true,"publicationSubtype":{"id":10}},"title":"Extremal bounds on earthquake movement from geodetic data: Application to the Landers earthquake","docAbstract":"We present a technique to place quantifiable bounds on the moment of an earthquake from geodetic data, assuming known fault geometry. Application of this technique to the 1992 Landers earthquake shows that the moment must have been between 0.84 and 1.15 × 1020 Nm with 90% confidence (M 7.25 to 7.34). We also find that to satisfy the data to this same level of confidence, the slip on the fault must have exceeded 7 m in at least one location, in good agreement with field mapping of the surface rupture.
","language":"English","publisher":"Seismological Society of America","doi":"10.1785/BSSA0840030660","usgsCitation":"Johnson, H.O., Agnew, D., and Hudnut, K., 1994, Extremal bounds on earthquake movement from geodetic data: Application to the Landers earthquake: Bulletin of the Seismological Society of America, v. 84, no. 3, p. 660-667, https://doi.org/10.1785/BSSA0840030660.","productDescription":"8 p.","startPage":"660","endPage":"667","costCenters":[],"links":[{"id":479333,"rank":2,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://resolver.caltech.edu/CaltechAUTHORS:20140806-094944484","text":"External Repository"},{"id":339459,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -117.48148758019548,\n 35.175884043309324\n ],\n [\n -117.48148758019548,\n 33.55266747577443\n ],\n [\n -115.32816726769562,\n 33.55266747577443\n ],\n [\n -115.32816726769562,\n 35.175884043309324\n ],\n [\n -117.48148758019548,\n 35.175884043309324\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"84","issue":"3","noUsgsAuthors":false,"publicationDate":"1994-06-01","publicationStatus":"PW","scienceBaseUri":"58e8a549e4b09da6799d63d3","contributors":{"authors":[{"text":"Johnson, Hadley O.","contributorId":190694,"corporation":false,"usgs":false,"family":"Johnson","given":"Hadley","email":"","middleInitial":"O.","affiliations":[],"preferred":false,"id":690383,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Agnew, Duncan Carr","contributorId":53686,"corporation":false,"usgs":true,"family":"Agnew","given":"Duncan Carr","affiliations":[],"preferred":false,"id":690384,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Hudnut, Ken","contributorId":44590,"corporation":false,"usgs":true,"family":"Hudnut","given":"Ken","email":"","affiliations":[],"preferred":false,"id":690385,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70186258,"text":"70186258 - 1994 - Slip triggered on southern California faults by the 1992 Joshua Tree, Landers, and big bear earthquakes","interactions":[],"lastModifiedDate":"2023-10-25T11:17:14.731095","indexId":"70186258","displayToPublicDate":"1994-06-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1135,"text":"Bulletin of the Seismological Society of America","onlineIssn":"1943-3573","printIssn":"0037-1106","active":true,"publicationSubtype":{"id":10}},"title":"Slip triggered on southern California faults by the 1992 Joshua Tree, Landers, and big bear earthquakes","docAbstract":"Five out of six functioning creepmeters on southern California faults recorded slip triggered at the time of some or all of the three largest events of the 1992 Landers earthquake sequence. Digital creep data indicate that dextral slip was triggered within 1 min of each mainshock and that maximum slip velocities occurred 2 to 3 min later. The duration of triggered slip events ranged from a few hours to several weeks. We note that triggered slip occurs commonly on faults that exhibit fault creep. To account for the observation that slip can be triggered repeatedly on a fault, we propose that the amplitude of triggered slip may be proportional to the depth of slip in the creep event and to the available near-surface tectonic strain that would otherwise eventually be released as fault creep. We advance the notion that seismic surface waves, perhaps amplified by sediments, generate transient local conditions that favor the release of tectonic strain to varying depths. Synthetic strain seismograms are presented that suggest increased pore pressure during periods of fault-normal contraction may be responsible for triggered slip, since maximum dextral shear strain transients correspond to times of maximum fault-normal contraction.
","language":"English","publisher":"Seismological Society of America","doi":"10.1785/BSSA0840030806","usgsCitation":"Bodin, P., Bilham, R.G., Behr, J., Gomberg, J., and Hudnut, K.W., 1994, Slip triggered on southern California faults by the 1992 Joshua Tree, Landers, and big bear earthquakes: Bulletin of the Seismological Society of America, v. 84, no. 3, p. 806-816, https://doi.org/10.1785/BSSA0840030806.","productDescription":"11 p.","startPage":"806","endPage":"816","costCenters":[],"links":[{"id":339030,"rank":2,"type":{"id":15,"text":"Index Page"},"url":"https://pubs.geoscienceworld.org/ssa/bssa/article/84/3/806/102697/Slip-triggered-on-southern-California-faults-by"},{"id":339031,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -117.48148758019548,\n 35.175884043309324\n ],\n [\n -117.48148758019548,\n 33.55266747577443\n ],\n [\n -115.32816726769562,\n 33.55266747577443\n ],\n [\n -115.32816726769562,\n 35.175884043309324\n ],\n [\n -117.48148758019548,\n 35.175884043309324\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"84","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"58e35f90e4b09da67997ecf0","contributors":{"authors":[{"text":"Bodin, Paul","contributorId":104142,"corporation":false,"usgs":true,"family":"Bodin","given":"Paul","affiliations":[],"preferred":false,"id":688041,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bilham, Roger G. 0000-0002-5547-4102","orcid":"https://orcid.org/0000-0002-5547-4102","contributorId":48200,"corporation":false,"usgs":true,"family":"Bilham","given":"Roger","email":"","middleInitial":"G.","affiliations":[],"preferred":true,"id":688042,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Behr, Jeff","contributorId":190285,"corporation":false,"usgs":false,"family":"Behr","given":"Jeff","email":"","affiliations":[],"preferred":false,"id":688043,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Gomberg, Joan","contributorId":77919,"corporation":false,"usgs":true,"family":"Gomberg","given":"Joan","affiliations":[],"preferred":false,"id":688044,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Hudnut, Kenneth W. 0000-0002-3168-4797 hudnut@usgs.gov","orcid":"https://orcid.org/0000-0002-3168-4797","contributorId":2550,"corporation":false,"usgs":true,"family":"Hudnut","given":"Kenneth","email":"hudnut@usgs.gov","middleInitial":"W.","affiliations":[{"id":237,"text":"Earthquake Science Center","active":true,"usgs":true},{"id":508,"text":"Office of the AD Hazards","active":true,"usgs":true}],"preferred":true,"id":688045,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70017110,"text":"70017110 - 1994 - Reconciling short recurrence intervals with minor deformation in the New Madrid seismic zone","interactions":[],"lastModifiedDate":"2025-09-15T16:03:45.771156","indexId":"70017110","displayToPublicDate":"1994-05-27T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3338,"text":"Science","active":true,"publicationSubtype":{"id":10}},"title":"Reconciling short recurrence intervals with minor deformation in the New Madrid seismic zone","docAbstract":"At least three great earthquakes occurred in the New Madrid seismic zone in 1811 and 1812. Estimates of present-day strain rates suggest that such events may have a repeat time of 1000 years or less. Paleoseismological data also indicate that earthquakes large enough to cause soil liquefaction have occurred several times in the past 5000 years. However, pervasive crustal deformation expected from such a high frequency of large earthquakes is not observed. This suggests that the seismic zone is a young feature, possibly as young as several tens of thousands of years old and no more than a few million years old.At least three great earthquakes occurred in the New Madrid seismic zone in 1811 and 1812. Estimates of present-day strain rates suggest that such events may have a repeat time of 1000 years or less. Paleoseismological data also indicate that earthquakes large enough to cause soil liquefaction have occurred several times in the past 5000 years. However, pervasive crustal deformation expected from such a high frequency of large earthquakes is not observed. This suggests that the seismic zone is a young feature, possibly as young as several tens of thousands of years old and no more than a few million years old.","language":"English","publisher":"American Association for the Advancement of Science","doi":"10.1126/science.264.5163.1308","issn":"00368075","usgsCitation":"Schweig, E., and Ellis, M., 1994, Reconciling short recurrence intervals with minor deformation in the New Madrid seismic zone: Science, v. 264, no. 5163, p. 1308-1311, https://doi.org/10.1126/science.264.5163.1308.","productDescription":"4 p.","startPage":"1308","endPage":"1311","costCenters":[],"links":[{"id":224915,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","otherGeospatial":"New Madrid seismic zone","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -89.95226344619657,\n 36.766547270310056\n ],\n [\n -89.95226344619657,\n 36.18104108952646\n ],\n [\n -89.09224537383166,\n 36.18104108952646\n ],\n [\n -89.09224537383166,\n 36.766547270310056\n ],\n [\n -89.95226344619657,\n 36.766547270310056\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"264","issue":"5163","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a96a0e4b0c8380cd820e7","contributors":{"authors":[{"text":"Schweig, E.S.","contributorId":34538,"corporation":false,"usgs":true,"family":"Schweig","given":"E.S.","email":"","affiliations":[],"preferred":false,"id":375435,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ellis, M.A.","contributorId":42716,"corporation":false,"usgs":true,"family":"Ellis","given":"M.A.","email":"","affiliations":[],"preferred":false,"id":375436,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70129019,"text":"70129019 - 1994 - A salmon population model for evaluating alternative flow regimes","interactions":[],"lastModifiedDate":"2014-10-16T10:45:31","indexId":"70129019","displayToPublicDate":"1994-05-26T10:43:13","publicationYear":"1994","noYear":false,"publicationType":{"id":4,"text":"Book"},"publicationSubtype":{"id":12,"text":"Conference publication"},"title":"A salmon population model for evaluating alternative flow regimes","docAbstract":"No abstract available.","largerWorkTitle":"Proceedings of the 21st Annual Water Resources Planning and Management Division Conference","conferenceTitle":"21st Annual Water Resources Planning and Management Division Conference","conferenceDate":"1994-05-23T00:00:00","conferenceLocation":"Denver, CO","language":"English","publisher":"American Society of Civil Engineers","publisherLocation":"New York, NY","usgsCitation":"Bartholow, J.M., and Waddle, T.J., 1994, A salmon population model for evaluating alternative flow regimes, 4 p.","productDescription":"4 p.","numberOfPages":"4","costCenters":[],"links":[{"id":295384,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5440de18e4b0b0a643c732a0","contributors":{"authors":[{"text":"Bartholow, J. M.","contributorId":46888,"corporation":false,"usgs":true,"family":"Bartholow","given":"J.","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":503334,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Waddle, T. J.","contributorId":52507,"corporation":false,"usgs":true,"family":"Waddle","given":"T.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":503335,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70129529,"text":"70129529 - 1994 - Water and wildlife enhancement with land retirement","interactions":[],"lastModifiedDate":"2018-03-08T12:12:10","indexId":"70129529","displayToPublicDate":"1994-05-26T10:18:00","publicationYear":"1994","noYear":false,"publicationType":{"id":4,"text":"Book"},"publicationSubtype":{"id":12,"text":"Conference publication"},"title":"Water and wildlife enhancement with land retirement","docAbstract":"No abstract available.","largerWorkTitle":"Water policy and management: Solving the problems","conferenceTitle":"Water policy and management: Solving the problems","conferenceDate":"1994-05-23T00:00:00","conferenceLocation":"Denver, CO","language":"English","publisher":"American Society of Civil Engineers","publisherLocation":"New York, NY","usgsCitation":"Ekstrand, E., and Johnson, R., 1994, Water and wildlife enhancement with land retirement, 4 p.","productDescription":"4 p.","numberOfPages":"4","costCenters":[],"links":[{"id":295639,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"544a1919e4b04d2014abfb81","contributors":{"authors":[{"text":"Ekstrand, E.","contributorId":21883,"corporation":false,"usgs":true,"family":"Ekstrand","given":"E.","affiliations":[],"preferred":false,"id":503771,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Johnson, R.","contributorId":24054,"corporation":false,"usgs":false,"family":"Johnson","given":"R.","email":"","affiliations":[],"preferred":false,"id":503772,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70129523,"text":"70129523 - 1994 - Technical understanding in successful environmental negotiations","interactions":[],"lastModifiedDate":"2014-10-23T09:40:02","indexId":"70129523","displayToPublicDate":"1994-05-26T09:38:00","publicationYear":"1994","noYear":false,"publicationType":{"id":4,"text":"Book"},"publicationSubtype":{"id":12,"text":"Conference publication"},"title":"Technical understanding in successful environmental negotiations","docAbstract":"No abstract available.","largerWorkTitle":"Water Policy and Management: Solving the Problems","conferenceTitle":"Water Policy and Management: Solving the Problems","conferenceDate":"1994-05-23T00:00:00","conferenceLocation":"Denver, CO","language":"English","publisher":"American Society of Civil Engineers","publisherLocation":"New York, NY","usgsCitation":"Burkardt, N., Lamb, B.L., and Waddle, T., 1994, Technical understanding in successful environmental negotiations, 3 p.","productDescription":"3 p.","numberOfPages":"3","costCenters":[],"links":[{"id":295631,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"544a1916e4b04d2014abfb79","contributors":{"authors":[{"text":"Burkardt, N.","contributorId":17554,"corporation":false,"usgs":true,"family":"Burkardt","given":"N.","affiliations":[],"preferred":false,"id":503754,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Lamb, B. L.","contributorId":9187,"corporation":false,"usgs":true,"family":"Lamb","given":"B.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":503753,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Waddle, T.","contributorId":101584,"corporation":false,"usgs":true,"family":"Waddle","given":"T.","affiliations":[],"preferred":false,"id":503755,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70243692,"text":"70243692 - 1994 - Seismologists meet “Down Under”","interactions":[],"lastModifiedDate":"2023-05-17T14:20:38.679007","indexId":"70243692","displayToPublicDate":"1994-05-24T09:12:35","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":7458,"text":"Eos Science News","active":true,"publicationSubtype":{"id":10}},"title":"Seismologists meet “Down Under”","docAbstract":"Planned presentations on hazard assessment and research weren't the only topics for discussion at the 27th General Assembly of the International Association of Seismology and Physics of the Earth's Interior (IASPEI), held from January 10–21 at the University of Victoria in Wellington, New Zealand.
There was a more timely one unfolding: California's Northridge earthquake. When conference participants awoke to news of the earthquake on January 18, they scrambled to action to gather the latest data available. Just 12 hours after the event, they held a general discussion about the earthquake.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/94EO00912","usgsCitation":"Ellsworth, W.L., 1994, Seismologists meet “Down Under”: Eos Science News, v. 75, no. 21, p. 234-235, https://doi.org/10.1029/94EO00912.","productDescription":"2 p.","startPage":"234","endPage":"235","costCenters":[],"links":[{"id":417133,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"New Zealand","city":"Wellington","otherGeospatial":"University of Victoria","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n 174.7689348861391,\n -41.29456587576638\n ],\n [\n 174.77204158330238,\n -41.28879791561476\n ],\n [\n 174.77165887423143,\n -41.288730253232764\n ],\n [\n 174.77114109137233,\n -41.288865577927645\n ],\n [\n 174.77051074701876,\n -41.2884934343401\n ],\n [\n 174.77012803794787,\n -41.2884257716413\n ],\n [\n 174.7696102550887,\n -41.28812128862993\n ],\n [\n 174.76938513210547,\n -41.287579981990476\n ],\n [\n 174.76925005831453,\n -41.28680184582654\n ],\n [\n 174.76870976315593,\n -41.28668343298847\n ],\n [\n 174.76812444340123,\n -41.28697100665163\n ],\n [\n 174.76762917283872,\n -41.287461570563494\n ],\n [\n 174.76711138997678,\n -41.28744465462815\n ],\n [\n 174.76695380388912,\n -41.287579981990476\n ],\n [\n 174.76724646376783,\n -41.2882566145889\n ],\n [\n 174.7670213407846,\n -41.2886795063992\n ],\n [\n 174.76729148836392,\n -41.28915314197314\n ],\n [\n 174.7673590252594,\n -41.289643689478396\n ],\n [\n 174.76729148836392,\n -41.29008348755477\n ],\n [\n 174.76699882848516,\n -41.290827754468104\n ],\n [\n 174.76661611941427,\n -41.290963074812325\n ],\n [\n 174.76657109481818,\n -41.29150435338471\n ],\n [\n 174.76600828736014,\n -41.2918088206077\n ],\n [\n 174.76569311518477,\n -41.2918764797969\n ],\n [\n 174.76526538151785,\n -41.29251923860201\n ],\n [\n 174.7650402585346,\n -41.29267147002338\n ],\n [\n 174.76618838574728,\n -41.29319581997585\n ],\n [\n 174.7689348861391,\n -41.29456587576638\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"75","issue":"21","noUsgsAuthors":false,"publicationDate":"2011-06-03","publicationStatus":"PW","contributors":{"authors":[{"text":"Ellsworth, William L. ellsworth@usgs.gov","contributorId":787,"corporation":false,"usgs":true,"family":"Ellsworth","given":"William","email":"ellsworth@usgs.gov","middleInitial":"L.","affiliations":[{"id":237,"text":"Earthquake Science Center","active":true,"usgs":true}],"preferred":true,"id":872931,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70209215,"text":"70209215 - 1994 - Earthquake refraction profiles of the root of the Sierra Nevada","interactions":[],"lastModifiedDate":"2020-03-25T13:02:06","indexId":"70209215","displayToPublicDate":"1994-05-24T08:26:28","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3524,"text":"Tectonics","active":true,"publicationSubtype":{"id":10}},"title":"Earthquake refraction profiles of the root of the Sierra Nevada","docAbstract":"We examine the seismic structure of the Sierra Nevada using records of nine earthquakes and one explosion in and near the Sierra, recorded on stations in the Sierra. We first interpret travel times from these paths, which are confined to a single tectonic block, in terms of one‐dimensional structures. The most nearly reversed pair of earthquakes, the 1966 Truckee and 1983 Durrwood Meadows earthquakes, share refracted (Pn) arrival times (corrected to surface focus) along a line t=8.75±0.25+Δ/8.0, suggesting that a nearly flat layer of 8.0 km/s mantle material lies at depths of 46–48 km. First arrivals from these events do not constrain velocities from ≈30 to 45 km depth. Secondary arrivals and some first arrivals from other earthquakes suggest that velocities in part of this region range between 6.9 and 7.8 km/s. The presence of this “7.x‐km/s” layer can help to explain previous contradictory observations. The 7.x‐km/s layer could be interpreted as either the mafic bottom of a silicic, Mesozoic magmatic arc or as accreted mafic underplating or rejuvenated mantle related to Cenozoic arc volcanism or Basin and Range spreading. Arrivals at stations in the foothills and the crest of the Sierra cannot be fit with a single longitudinal structure, indicating a lateral variation of velocity structure. These variations support previously inferred variations of lithospheric structure, with higher‐velocity, thinner crust to the west beneath the Sierran foothills and slower‐velocity crust (or possibly upper mantle) beneath the high mountains in the eastern Sierra. Rapid changes in arrival times between stations separated by short distances in the eastern Sierra suggest that a sharp boundary exists between the Sierra and the Basin and Range at Moho depths. We also present fresh evidence of the asymmetry of the root of the Sierra, wherein arrivals from earthquakes on the west of the Sierra are delayed within the Sierra and return to original values in the Basin and Range, while arrivals from earthquakes and explosions from the Sierra into the Great Valley. We suggest that if the 7.x‐km/s material occurs in a wedge above the Moho, then the asymmetry can be explained by arrivals from the west being delayed by the dipping 8.0‐km/s Moho, while those from the east may be entering the root along a 7.x‐km/s layer that is near the depth of the Basin and Range Moho.
Two species of mosquitofish (family Poeciliidae) known to hybridize in nature were introduced into freshwater habitats inside Biosphere 2, and their population genetics were monitored after 2 years. Within four to six generations, nuclear and cytoplasmic markers characteristic of Gambusia holbrooki had risen greatly in frequency, although some Gambusia affinis alleles and haplotypes were retained primarily in recombinant genotypes, indicative of introgressive hybridization. The temporal cytonuclear dynamics proved similar to population genetic changes observed in replicated experimental hybrid populations outside of Biosphere 2, thus indicating strong directional selection favoring G. holbrooki genotypes across the range of environments monitored. When interpreted in the context of species-specific population demographies observed previously, results suggest that the extremely rapid evolution in these zones of secondary contact is attributable primarily to species differences in life-history traits.
","language":"English","publisher":"Proceedings of the National Academy of Sciences of the United States of America","doi":"10.1073/pnas.91.11.5066","usgsCitation":"Scribner, K., and Avise, J.C., 1994, Cytonuclear genetics of experimental fish hybrid zones inside Biosphere 2: PNAS, v. 91, no. 11, p. 5066-5069, https://doi.org/10.1073/pnas.91.11.5066.","productDescription":"4 p.","startPage":"5066","endPage":"5069","costCenters":[{"id":114,"text":"Alaska Science Center","active":true,"usgs":true}],"links":[{"id":491480,"rank":2,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://escholarship.org/uc/item/4c91621h","text":"External Repository"},{"id":339149,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"91","issue":"11","noUsgsAuthors":false,"publicationDate":"1994-05-24","publicationStatus":"PW","scienceBaseUri":"58e4b0b4e4b09da6799977c3","contributors":{"authors":[{"text":"Scribner, K.T.","contributorId":97033,"corporation":false,"usgs":true,"family":"Scribner","given":"K.T.","email":"","affiliations":[],"preferred":false,"id":688458,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Avise, John C.","contributorId":182338,"corporation":false,"usgs":false,"family":"Avise","given":"John","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":688459,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70017111,"text":"70017111 - 1994 - Galileo multispectral imaging of the north polar and eastern limb regions of the moon","interactions":[],"lastModifiedDate":"2025-09-15T16:09:25.296376","indexId":"70017111","displayToPublicDate":"1994-05-20T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3338,"text":"Science","active":true,"publicationSubtype":{"id":10}},"title":"Galileo multispectral imaging of the north polar and eastern limb regions of the moon","docAbstract":"Multispectral images obtained during the Galileo probe's second encounter with the moon reveal the compositional nature of the north polar regions and the northeastern limb. Mare deposits in these regions are found to be primarily low to medium titanium lavas and, as on the western limb, show only slight spectral heterogeneity. The northern light plains are found to have the spectral characteristics of highlands materials, show little evidence for the presence of cryptomaria, and were most likely emplaced by impact processes regardless of their age.Multispectral images obtained during the Galileo probe's second encounter with the moon reveal the compositional nature of the north polar regions and the northeastern limb. Mare deposits in these regions are found to be primarily low to medium titanium lavas and, as on the western limb, show only slight spectral heterogeneity. The northern light plains are found to have the spectral characteristics of highlands materials, show little evidence for the presence of cryptomaria, and were most likely emplaced by impact processes regardless of their age.","language":"English","publisher":"American Association for the Advancement of Science","doi":"10.1126/science.264.5162.1112","issn":"00368075","usgsCitation":"Belton, M.J., Greeley, R., Greenberg, R., Geissler, P., McEwen, A., Klaasen, K., Heffernan, C., Breneman, H., Johnson, T.V., Head, J.W., Pieters, C., Neukum, G., Chapman, C.R., Anger, C., Carr, M.H., Davies, M.E., Fanale, F.P., Gierasch, P., Thompson, W., Veverka, J., Sagan, C., Ingersoll, A., and Pilcher, C., 1994, Galileo multispectral imaging of the north polar and eastern limb regions of the moon: Science, v. 264, no. 5162, p. 1112-1115, https://doi.org/10.1126/science.264.5162.1112.","productDescription":"4 p.","startPage":"1112","endPage":"1115","costCenters":[],"links":[{"id":224916,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"264","issue":"5162","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a14ade4b0c8380cd54aed","contributors":{"authors":[{"text":"Belton, M. J. S.","contributorId":79223,"corporation":false,"usgs":true,"family":"Belton","given":"M.","email":"","middleInitial":"J. S.","affiliations":[],"preferred":false,"id":375454,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Greeley, R.","contributorId":6538,"corporation":false,"usgs":true,"family":"Greeley","given":"R.","email":"","affiliations":[],"preferred":false,"id":375437,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Greenberg, R.","contributorId":26778,"corporation":false,"usgs":true,"family":"Greenberg","given":"R.","email":"","affiliations":[],"preferred":false,"id":375443,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Geissler, P.","contributorId":45662,"corporation":false,"usgs":true,"family":"Geissler","given":"P.","email":"","affiliations":[],"preferred":false,"id":375448,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"McEwen, A.","contributorId":39105,"corporation":false,"usgs":true,"family":"McEwen","given":"A.","affiliations":[],"preferred":false,"id":375446,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Klaasen, K.P.","contributorId":56806,"corporation":false,"usgs":true,"family":"Klaasen","given":"K.P.","email":"","affiliations":[],"preferred":false,"id":375451,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Heffernan, C.","contributorId":37482,"corporation":false,"usgs":true,"family":"Heffernan","given":"C.","email":"","affiliations":[],"preferred":false,"id":375445,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Breneman, H.","contributorId":59186,"corporation":false,"usgs":true,"family":"Breneman","given":"H.","affiliations":[],"preferred":false,"id":375452,"contributorType":{"id":1,"text":"Authors"},"rank":8},{"text":"Johnson, T. V.","contributorId":79619,"corporation":false,"usgs":false,"family":"Johnson","given":"T.","email":"","middleInitial":"V.","affiliations":[],"preferred":false,"id":375455,"contributorType":{"id":1,"text":"Authors"},"rank":9},{"text":"Head, J. W. III","contributorId":106267,"corporation":false,"usgs":true,"family":"Head","given":"J.","suffix":"III","email":"","middleInitial":"W.","affiliations":[],"preferred":false,"id":375459,"contributorType":{"id":1,"text":"Authors"},"rank":10},{"text":"Pieters, C.","contributorId":104636,"corporation":false,"usgs":true,"family":"Pieters","given":"C.","email":"","affiliations":[],"preferred":false,"id":375457,"contributorType":{"id":1,"text":"Authors"},"rank":11},{"text":"Neukum, G.","contributorId":105443,"corporation":false,"usgs":true,"family":"Neukum","given":"G.","email":"","affiliations":[],"preferred":false,"id":375458,"contributorType":{"id":1,"text":"Authors"},"rank":12},{"text":"Chapman, C. R.","contributorId":12984,"corporation":false,"usgs":true,"family":"Chapman","given":"C.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":375439,"contributorType":{"id":1,"text":"Authors"},"rank":13},{"text":"Anger, C.","contributorId":50296,"corporation":false,"usgs":true,"family":"Anger","given":"C.","email":"","affiliations":[],"preferred":false,"id":375449,"contributorType":{"id":1,"text":"Authors"},"rank":14},{"text":"Carr, M. H.","contributorId":84727,"corporation":false,"usgs":true,"family":"Carr","given":"M.","email":"","middleInitial":"H.","affiliations":[{"id":131,"text":"Astrogeology Science Center","active":true,"usgs":true}],"preferred":false,"id":375456,"contributorType":{"id":1,"text":"Authors"},"rank":15},{"text":"Davies, M. E.","contributorId":26050,"corporation":false,"usgs":true,"family":"Davies","given":"M.","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":375442,"contributorType":{"id":1,"text":"Authors"},"rank":16},{"text":"Fanale, F. P.","contributorId":24925,"corporation":false,"usgs":false,"family":"Fanale","given":"F.","email":"","middleInitial":"P.","affiliations":[],"preferred":false,"id":375441,"contributorType":{"id":1,"text":"Authors"},"rank":17},{"text":"Gierasch, P.J.","contributorId":9005,"corporation":false,"usgs":true,"family":"Gierasch","given":"P.J.","email":"","affiliations":[],"preferred":false,"id":375438,"contributorType":{"id":1,"text":"Authors"},"rank":18},{"text":"Thompson, W.R.","contributorId":16170,"corporation":false,"usgs":true,"family":"Thompson","given":"W.R.","email":"","affiliations":[],"preferred":false,"id":375440,"contributorType":{"id":1,"text":"Authors"},"rank":19},{"text":"Veverka, J.","contributorId":71689,"corporation":false,"usgs":true,"family":"Veverka","given":"J.","email":"","affiliations":[],"preferred":false,"id":375453,"contributorType":{"id":1,"text":"Authors"},"rank":20},{"text":"Sagan, C.","contributorId":42336,"corporation":false,"usgs":true,"family":"Sagan","given":"C.","email":"","affiliations":[],"preferred":false,"id":375447,"contributorType":{"id":1,"text":"Authors"},"rank":21},{"text":"Ingersoll, A.P.","contributorId":54735,"corporation":false,"usgs":true,"family":"Ingersoll","given":"A.P.","email":"","affiliations":[],"preferred":false,"id":375450,"contributorType":{"id":1,"text":"Authors"},"rank":22},{"text":"Pilcher, C.B.","contributorId":31917,"corporation":false,"usgs":true,"family":"Pilcher","given":"C.B.","email":"","affiliations":[],"preferred":false,"id":375444,"contributorType":{"id":1,"text":"Authors"},"rank":23}]}} ,{"id":70243700,"text":"70243700 - 1994 - Using regional seismic networks to study the Earth's deep interior","interactions":[],"lastModifiedDate":"2023-05-17T17:58:17.442694","indexId":"70243700","displayToPublicDate":"1994-05-17T12:49:59","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":7458,"text":"Eos Science News","active":true,"publicationSubtype":{"id":10}},"title":"Using regional seismic networks to study the Earth's deep interior","docAbstract":"Long-period or broadband data from global stations or small aperture arrays have traditionally been used to study the Earth's deep interior. However, recent seismic studies have shown that regional seismic networks can be an important tool in high- resolution studies of the upper mantle, coremantle boundary, and the inner and outer core, as well as the earthquake source.
Although these networks were established to monitor regional earthquakes, many have systematically archived seismograms from distant earthquakes that provide a wealth of information on the Earth's deep interior.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/94EO00897","usgsCitation":"Benz, H.M., Vidale, J., and Mori, J., 1994, Using regional seismic networks to study the Earth's deep interior: Eos Science News, v. 75, no. 20, p. 225-229, https://doi.org/10.1029/94EO00897.","productDescription":"4 p.","startPage":"225","endPage":"229","costCenters":[],"links":[{"id":417164,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"75","issue":"20","noUsgsAuthors":false,"publicationDate":"2011-06-03","publicationStatus":"PW","contributors":{"authors":[{"text":"Benz, Harley M. 0000-0002-6860-2134 benz@usgs.gov","orcid":"https://orcid.org/0000-0002-6860-2134","contributorId":794,"corporation":false,"usgs":true,"family":"Benz","given":"Harley","email":"benz@usgs.gov","middleInitial":"M.","affiliations":[{"id":300,"text":"Geologic Hazards Science Center","active":true,"usgs":true}],"preferred":true,"id":872952,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Vidale, J.E.","contributorId":55849,"corporation":false,"usgs":true,"family":"Vidale","given":"J.E.","email":"","affiliations":[],"preferred":false,"id":872953,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Mori, J.","contributorId":24923,"corporation":false,"usgs":true,"family":"Mori","given":"J.","email":"","affiliations":[],"preferred":false,"id":872954,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70210132,"text":"70210132 - 1994 - Compositions, growth mechanisms, and temporal relations of hydrothermal sulfide‐sulfate‐silica chimneys at the northern Cleft segment, Juan de Fuca Ridge","interactions":[],"lastModifiedDate":"2021-03-31T14:49:14.304418","indexId":"70210132","displayToPublicDate":"1994-05-14T14:48:26","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":7514,"text":"Journal of Geophysical Research - Solid Earth","active":true,"publicationSubtype":{"id":10}},"title":"Compositions, growth mechanisms, and temporal relations of hydrothermal sulfide‐sulfate‐silica chimneys at the northern Cleft segment, Juan de Fuca Ridge","docAbstract":"Three active hydrothermal vents forming sulfide mounds and chimneys (Monolith, Fountain, and Pipe Organ) and more widely distributed inactive chimneys are spatially related to a system of discontinuous fissures and young sheet flow lavas at the northern Cleft segment, Juan de Fuca Ridge. The formation of zoned tubular Curich chimneys (type I) on the Monolith sulfide mound is related to focused flow of high‐temperature (to 328°C) fluid. Bulbous chimneys (type II or “beehives”) at the Monolith and Fountain vents are products of diffuse high‐temperature (to 315°C) discharge. A broader zone of vigorous mixing between the hydrothermal fluid and seawater results in quench crystallization of anhydrite‐rich shells. Columnar Zn‐sulfide‐rich chimneys with narrow channelways (type III) are constructed where focused and relatively low‐temperature (261°C) fluid vents directly from the basalt substrate. The bulk chemistry (low Cu; high Pb, Ag, and SiO2 contents), mineralogy (pyrite‐marcasite‐wurtzite‐amorphous silica‐anglesite), colloform and filamentous textures, and oxygen isotope characteristics of inactive (type IV) chimneys indicate a low‐temperature (<250°C) origin involving diffuse and sluggish flow patterns and conductive cooling. Seafloor observations and 210Pb data indicate that (1) type IV chimneys are products of an earlier period of hydrothermal activity that ended no more than 60 years ago but prior to the sheet flow eruption, (2) the high‐temperature Monolith and Fountain vents are manifestations of the same heating event (shallow emplacement of magma) that led to the sheet flow eruption and recent megaplumes, and (3) the Pipe Organ Vent is in a very youthful stage of development and chimney deposition postdates the sheet flow eruption.
","language":"English","publisher":"Wiley","doi":"10.1029/93JB02871","usgsCitation":"Koski, R.A., Jonasson, I., Kadko, D., Smith, V.K., and Wong, F.L., 1994, Compositions, growth mechanisms, and temporal relations of hydrothermal sulfide‐sulfate‐silica chimneys at the northern Cleft segment, Juan de Fuca Ridge: Journal of Geophysical Research - Solid Earth, v. 99, no. B3, p. 4813-4832, https://doi.org/10.1029/93JB02871.","productDescription":"20 p.","startPage":"4813","endPage":"4832","costCenters":[{"id":312,"text":"Geology, Minerals, Energy, and Geophysics Science Center","active":true,"usgs":true},{"id":520,"text":"Pacific Coastal and Marine Science Center","active":true,"usgs":true}],"links":[{"id":375249,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California, Oregon, Washington","otherGeospatial":"Juan de Fuca Ridge","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -130.95703125,\n 51.508742458803326\n ],\n [\n -131.220703125,\n 42.90816007196054\n ],\n [\n -124.8046875,\n 41.934976500546604\n ],\n [\n -124.892578125,\n 42.58544425738491\n ],\n [\n -124.67285156250001,\n 43.644025847699496\n ],\n [\n -124.3212890625,\n 46.6795944656402\n ],\n [\n -124.98046874999999,\n 48.25394114463431\n ],\n [\n -130.95703125,\n 51.508742458803326\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"99","issue":"B3","noUsgsAuthors":false,"publicationDate":"2012-09-20","publicationStatus":"PW","contributors":{"authors":[{"text":"Koski, Randolph A. rkoski@usgs.gov","contributorId":2949,"corporation":false,"usgs":true,"family":"Koski","given":"Randolph","email":"rkoski@usgs.gov","middleInitial":"A.","affiliations":[],"preferred":true,"id":790191,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Jonasson, I.","contributorId":25349,"corporation":false,"usgs":true,"family":"Jonasson","given":"I.","email":"","affiliations":[],"preferred":false,"id":790192,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Kadko, D.","contributorId":87686,"corporation":false,"usgs":true,"family":"Kadko","given":"D.","email":"","affiliations":[],"preferred":false,"id":790193,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Smith, Virginia K.","contributorId":72021,"corporation":false,"usgs":true,"family":"Smith","given":"Virginia","email":"","middleInitial":"K.","affiliations":[],"preferred":false,"id":790194,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Wong, Florence L. 0000-0002-3918-5896 fwong@usgs.gov","orcid":"https://orcid.org/0000-0002-3918-5896","contributorId":1990,"corporation":false,"usgs":true,"family":"Wong","given":"Florence","email":"fwong@usgs.gov","middleInitial":"L.","affiliations":[{"id":520,"text":"Pacific Coastal and Marine Science Center","active":true,"usgs":true}],"preferred":true,"id":790195,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70016960,"text":"70016960 - 1994 - Comparison of 14C ages of hydrothermal petroleums","interactions":[],"lastModifiedDate":"2025-03-13T15:07:49.716212","indexId":"70016960","displayToPublicDate":"1994-05-06T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2958,"text":"Organic Geochemistry","active":true,"publicationSubtype":{"id":10}},"title":"Comparison of 14C ages of hydrothermal petroleums","docAbstract":"In order to set limits on the time frame of formation of hydrothermal petroleum, we have obtained 14C ages on samples from three diverse regions; Gulf of California (Guaymas Basin), Northeast Pacific Ocean (Escanaba Trough and Middle Valley), and the East African Rift (Tanganyika Trough). The results date the source of carbon and therefore provide maximum ages for the formation and emplacement of the hydrothermal petroleums. The youngest petroleum occurs iin the Souther Trough of Guaymas Basin (3200–6600 yr, mean 4692 yr); in the Northern Trough the petroleum is slightly older (7400 yr). Significantly older hydrothermal petroleum occurs in Escanaba Trough (17,000 yr) and Middle Valley (29,000 yr). A continental example from the East African Rift has an age of 25,000 yr, comparable to the ages observed in the oceanic samples from the Northeast Pacific Ocean. These ages affirm that hydrothermal petroleum formation is a very rapid process and took place some time between the latest Pleistocene and the present in these active hydrothermal systems.
","language":"English","publisher":"Elsevier","doi":"10.1016/0146-6380(94)90103-1","usgsCitation":"Simoneit, B.R., and Kvenvolden, K.A., 1994, Comparison of 14C ages of hydrothermal petroleums: Organic Geochemistry, v. 21, no. 5, p. 525-529, https://doi.org/10.1016/0146-6380(94)90103-1.","productDescription":"5 p.","startPage":"525","endPage":"529","costCenters":[],"links":[{"id":224520,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"21","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f83de4b0c8380cd4cf79","contributors":{"authors":[{"text":"Simoneit, Bernd R. T.","contributorId":51021,"corporation":false,"usgs":true,"family":"Simoneit","given":"Bernd","email":"","middleInitial":"R. T.","affiliations":[],"preferred":false,"id":374975,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kvenvolden, Keith A. kkvenvolden@usgs.gov","contributorId":3384,"corporation":false,"usgs":true,"family":"Kvenvolden","given":"Keith","email":"kkvenvolden@usgs.gov","middleInitial":"A.","affiliations":[{"id":520,"text":"Pacific Coastal and Marine Science Center","active":true,"usgs":true}],"preferred":true,"id":374976,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70199238,"text":"70199238 - 1994 - Chemistry of dissolved organic matter in rivers, lakes, and reservoirs","interactions":[],"lastModifiedDate":"2018-09-12T09:09:53","indexId":"70199238","displayToPublicDate":"1994-05-05T09:08:01","publicationYear":"1994","noYear":false,"publicationType":{"id":5,"text":"Book chapter"},"publicationSubtype":{"id":24,"text":"Book Chapter"},"chapter":"7","title":"Chemistry of dissolved organic matter in rivers, lakes, and reservoirs","docAbstract":"Recent investigations provide new insight on the structural chemistry of dissolved organic matter (DOM) in freshwater environments and the role of these structures in contaminant binding. Molecular models of DOM derived from allochthonous and autochthonous sources show that short-chain, branched, and alicyclic structures are terminated by carboxyl or methyl groups in DOM from both sources. Allochthonous DOM, however, had aromatic structures indicative of tannin and lignin residues, whereas the autochthonous DOM was characterized by aliphatic alicyclic structures indicative of lipid hydrocarbons as the source. DOM isolated from different morphoclimatic regions had minor structural differences.
","largerWorkType":{"id":4,"text":"Book"},"largerWorkTitle":"Environmental chemistry of lakes and reservoirs ","language":"English","publisher":"American Chemical Society","doi":"10.1021/ba-1994-0237.ch007","usgsCitation":"Leenheer, J., 1994, Chemistry of dissolved organic matter in rivers, lakes, and reservoirs, chap. 7 of Environmental chemistry of lakes and reservoirs , v. 237, p. 195-221, https://doi.org/10.1021/ba-1994-0237.ch007.","productDescription":"27 p.","startPage":"195","endPage":"221","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":357248,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"237","noUsgsAuthors":false,"publicationDate":"2009-07-22","publicationStatus":"PW","scienceBaseUri":"5c111330e4b034bf6a813afb","contributors":{"authors":[{"text":"Leenheer, J. A.","contributorId":195371,"corporation":false,"usgs":false,"family":"Leenheer","given":"J. A.","affiliations":[],"preferred":false,"id":744784,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70129396,"text":"70129396 - 1994 - Ecological mapping of whitebark pine in Glacier National Park","interactions":[],"lastModifiedDate":"2014-10-21T13:50:39","indexId":"70129396","displayToPublicDate":"1994-05-03T13:46:00","publicationYear":"1994","noYear":false,"publicationType":{"id":4,"text":"Book"},"publicationSubtype":{"id":12,"text":"Conference publication"},"title":"Ecological mapping of whitebark pine in Glacier National Park","docAbstract":"No abstract available.","largerWorkTitle":"Proceedings of a workshop on research and management in whitebark pine ecosystems","conferenceTitle":"Proceedings of a workshop on research and management in whitebark pine ecosystems","conferenceDate":"1994-05-03T00:00:00","conferenceLocation":"Glacier National Park, MT","language":"English","publisher":"Midcontinent Ecological Science Center, Glacier Field Unit","publisherLocation":"Fort Collins, CO","usgsCitation":"Kendall, K.C., 1994, Ecological mapping of whitebark pine in Glacier National Park, 13 p.","productDescription":"13 p.","numberOfPages":"13","costCenters":[],"links":[{"id":295580,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Montana","otherGeospatial":"Glacier National Park","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"544775ade4b0f888a81b830e","contributors":{"authors":[{"text":"Kendall, K. C.","contributorId":29758,"corporation":false,"usgs":true,"family":"Kendall","given":"K.","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":503665,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ]}