Microscopic filiform morphologies in gold which are indistinguishable from forms originally interpreted as bacterial in origin were produced in the laboratory by treating amalgams made from natural and artificial gold with hot nitric acid. Textures ranging from cobblestone to deeply crenulated to nodular filiform were produced in the laboratory from all tested natural and artificial gold amalgams; analogous textures widespread in Alaskan placer gold may have a similar inorganic origin. These results indicate that morphology alone cannot be considered adequate evidence of microbial involvement in gold formation.
A generally unrecognized type of pyroclastic deposit was produced by rapid avalanches of intimately mixed snow and hot pyroclastic debris during eruptions at Mount St. Helens, Nevado del Ruiz, and Redoubt Volcano between 1982 and 1989. These \"mixed avalanches\" traveled as far as 14 km at velocities up to ∼27 m/s, involved as much as 107 m3 of rock and ice, and left unmelted deposits of single flow units as thick as 5 m. During flow downslope, heat transfer from hot rocks to snow produced meltwater that partially saturated the mixtures, apparently giving these mixed avalanches mobilities equal to or greater than those of \"dry\" debris avalanches of similar volume. The avalanches studied for this report began as snow avalanches, triggered during explosive phases of the eruptions by ballistic bombardment of snow slopes by hot pyroclastic debris. Erosion by the avalanches incorporated additional snow, fragments of glacier ice, and other rock debris.
Mixed-avalanche deposits were massive, very poorly sorted, and ungraded to inversely graded prior to melting. Although rock debris composed as much as 70 wt% of the frozen samples, the bulk volumetric content of rock debris was only 9% to 36%. Snow and ice composed between 36% and 72% of the frozen samples, with void space making up the remainder of the volume. Deformation and consolidation after melting of the ice content reduced the deposits to loose, porous layers that were only a fraction of their original thickness and that later gave little hint of their origin. After melting and desiccation, the deposits are highly susceptible to erosion and unlikely to be well preserved in the stratigraphic record.
","language":"English","publisher":"Geological Society of America","doi":"10.1130/0016-7606(1994)106<1351:VMAADE>2.3.CO;2","usgsCitation":"Pierson, T., and Janda, R.J., 1994, Volcanic mixed avalanches: A distinct eruption-triggered mass-flow process at snow-clad volcanoes: Geological Society of America Bulletin, v. 106, no. 10, p. 1351-1358, https://doi.org/10.1130/0016-7606(1994)106<1351:VMAADE>2.3.CO;2.","productDescription":"8 p.","startPage":"1351","endPage":"1358","costCenters":[{"id":157,"text":"Cascades Volcano Observatory","active":false,"usgs":true},{"id":615,"text":"Volcano Hazards Program","active":true,"usgs":true}],"links":[{"id":224828,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"Colombia, United States","state":"Alaska, Washington","otherGeospatial":"Mount St. Helens, Nevado del Ruiz, Redoubt Volcano","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -122.37258911132812,\n 46.10942153064161\n ],\n [\n -122.04849243164061,\n 46.10942153064161\n ],\n [\n -122.04849243164061,\n 46.3838859037291\n ],\n [\n -122.37258911132812,\n 46.3838859037291\n ],\n [\n -122.37258911132812,\n 46.10942153064161\n ]\n ]\n ]\n }\n },\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -153.06838989257812,\n 60.28272771685622\n ],\n [\n -152.3968505859375,\n 60.28272771685622\n ],\n [\n -152.3968505859375,\n 60.79670385526034\n ],\n [\n -153.06838989257812,\n 60.79670385526034\n ],\n [\n -153.06838989257812,\n 60.28272771685622\n ]\n ]\n ]\n }\n },\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -75.44586181640625,\n 4.681823392265324\n ],\n [\n -74.91714477539062,\n 4.681823392265324\n ],\n [\n -74.91714477539062,\n 5.033490930561194\n ],\n [\n -75.44586181640625,\n 5.033490930561194\n ],\n [\n -75.44586181640625,\n 4.681823392265324\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"106","issue":"10","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bc2fbe4b08c986b32aebc","contributors":{"authors":[{"text":"Pierson, T.C. 0000-0001-9002-4273","orcid":"https://orcid.org/0000-0001-9002-4273","contributorId":41855,"corporation":false,"usgs":true,"family":"Pierson","given":"T.C.","affiliations":[{"id":157,"text":"Cascades Volcano Observatory","active":false,"usgs":true}],"preferred":true,"id":375704,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Janda, R. J. 0000-0002-3251-8088","orcid":"https://orcid.org/0000-0002-3251-8088","contributorId":64693,"corporation":false,"usgs":true,"family":"Janda","given":"R.","email":"","middleInitial":"J.","affiliations":[{"id":157,"text":"Cascades Volcano Observatory","active":false,"usgs":true}],"preferred":true,"id":375705,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70017324,"text":"70017324 - 1994 - Palynology, paleoclimatology and correlation of middle Miocene beds from Porcupine River (locality 90-1), Alaska","interactions":[],"lastModifiedDate":"2013-03-25T16:38:17","indexId":"70017324","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3217,"text":"Quaternary International","active":true,"publicationSubtype":{"id":10}},"title":"Palynology, paleoclimatology and correlation of middle Miocene beds from Porcupine River (locality 90-1), Alaska","docAbstract":"Beds in the Upper Ramparts Canyon of the Porcupine River, Alaska (67?? 20' N, 141?? 20' W), yielded a flora rich in pollen of hardwood genera now found in the temperate climates of North America and Asia. The beds are overlain or enclosed by two basalt flows which were dated to 15.2 ?? 0.1 Ma by the 40Ar 39Ar method, fixing the period of the greatest abundance of warm-loving genera to the early part of the middle Miocene. The assemblage is the most northern middle Miocene flora known in Alaska. Organic bed 1 underlies the basalt and is older than 15.2 Ma, but is of early to middle Miocene age. The pollen assemblage from organic bed 1 is dominated by conifer pollen from the pine and redwood-cypress-yew families with rare occurrences of temperate hardwoods. Organic bed 2 is a forest floor containing redwood trees in life position, engulfed by the lowest basalt flow. A pine log has growth rings up to 1 cm thick. Organic beds 3 and 4 comprise lacustrine sediment and peat between the two basalt flows. Their palynoflora contain conifers and hardwood genera, of which about 40% have modern temperate climatic affinities. Hickory, katsura, walnut, sweet gum, wingnut, basswood and elm pollen are consistently present, and beech and oak alone make up about 20% of the pollen assemblage. A warm high latitude climate is indicated for all of the organic beds, but organic bed 3 was deposited under a time of peak warmth. Climate data derived by comparison with modern east Asian vegetation suggest that, at the time of deposition of organic bed 3, the Mean Annual Temperature (MAT) was ca. 9??C, the Warm Month Mean Temperature (WMMT) was ??? 20??C and the Cold Month Mean Temperature (CMMT) was ca. -2??C. In contrast, the modern MAT for the region is -8.6??C, WMMT is 12.6??C and CMMT is -28??C. Organic beds 3 and 4 correlate to rocks of the middle Miocene-late Seldovian Stage of Cook Inlet and also probably correlate to, and more precisely date, the lower third of the Suntrana Formation in the Alaska Range, beds at Unalaklect, part of the upper Mackenzie Bay sequence in the Beaufort-Mackenzie basin, and the Mary Sachs gravel of Banks Island. This suggests that forests with significant percentages of temperate deciduous angiosperms existed between latitudes 60?? and 72??N during the early middle Miocene. ?? 1994.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Quaternary International","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","doi":"10.1016/1040-6182(94)90006-X","issn":"10406182","usgsCitation":"White, J.M., and Ager, T.A., 1994, Palynology, paleoclimatology and correlation of middle Miocene beds from Porcupine River (locality 90-1), Alaska: Quaternary International, v. 22-23, no. C, p. 43-77, https://doi.org/10.1016/1040-6182(94)90006-X.","startPage":"43","endPage":"77","numberOfPages":"35","costCenters":[],"links":[{"id":224591,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":270055,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/1040-6182(94)90006-X"}],"volume":"22-23","issue":"C","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a74a7e4b0c8380cd7775a","contributors":{"authors":[{"text":"White, J. M.","contributorId":40268,"corporation":false,"usgs":true,"family":"White","given":"J.","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":376133,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ager, T. A.","contributorId":88386,"corporation":false,"usgs":true,"family":"Ager","given":"T.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":376134,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70017334,"text":"70017334 - 1994 - Artifacts resembling budding bacteria produced in placer-gold amalgams by nitric acid leaching","interactions":[],"lastModifiedDate":"2024-01-21T22:56:31.365267","indexId":"70017334","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1796,"text":"Geology","active":true,"publicationSubtype":{"id":10}},"title":"Artifacts resembling budding bacteria produced in placer-gold amalgams by nitric acid leaching","docAbstract":"Microscopic filiform morphologies in gold which are indistinguishable from forms originally interpreted as bacterial in origin were produced in the laboratory by treating amalgams made from natural and artificial gold with hot nitric acid. Textures ranging from cobblestone to deeply crenulated to nodular filiform were produced in the laboratory from all tested natural and artificial gold amalgams; analogous textures widespread in Alaskan placer gold may have a similar inorganic origin. These results indicate that morphology alone cannot be considered adequate evidence of microbial involvement in gold formation.
The brachiopod genus Verneuilia Hall and Clarke, 1893, is recognized for the first time in North America, where it is represented by a new species described here, V. langenstrasseni. This occurrence not only extends the geographic range of the genus, but also the lower age and stratigraphic limit into the Eifelian (early Middle Devonian). Previously, the oldest known species was the type, V. cheiropteryx d'Archiac and de Verneuil, 1842, from the Givetian (late Middle Devonian) of Germany. Internal structures of V. langenstrasseni n. sp. are similar to those of genera in the ambocoeliid subfamily Rhynchospiriferinae, providing the first good evidence of a systematic relationship.
No abstract available.
","language":"English","publisher":"American Journal of Science","doi":"10.2475/ajs.294.4.485","usgsCitation":"Reynolds, R.L., Tuttle, M., Rice, C.A., Fishman, N., Karachewski, J.A., and Sherman, D.M., 1994, Magnetization and geochemistry of greigite-bearing Cretaceous strata, North Slope basin, Alaska: American Journal of Science, v. 294, no. 4, p. 485-528, https://doi.org/10.2475/ajs.294.4.485.","productDescription":"44 p.","startPage":"485","endPage":"528","numberOfPages":"44","costCenters":[{"id":211,"text":"Crustal Geophysics and Geochemistry Science Center","active":true,"usgs":true},{"id":318,"text":"Geosciences and Environmental Change Science Center","active":true,"usgs":true}],"links":[{"id":479389,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.2475/ajs.294.4.485","text":"Publisher Index Page"},{"id":228507,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Alaska","otherGeospatial":"North Slope basin","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -166.63402154331217,\n 71.35\n ],\n [\n -166.63402154331217,\n 69.09402627659142\n ],\n [\n -142.63731197539582,\n 69.09402627659142\n ],\n [\n -142.63731197539582,\n 71.35\n ],\n [\n -166.63402154331217,\n 71.35\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"294","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a4b9de4b0c8380cd69695","contributors":{"authors":[{"text":"Reynolds, Richard L. 0000-0002-4572-2942 rreynolds@usgs.gov","orcid":"https://orcid.org/0000-0002-4572-2942","contributorId":139068,"corporation":false,"usgs":true,"family":"Reynolds","given":"Richard","email":"rreynolds@usgs.gov","middleInitial":"L.","affiliations":[{"id":318,"text":"Geosciences and Environmental Change Science Center","active":true,"usgs":true}],"preferred":true,"id":376373,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Tuttle, Michele L. mtuttle@usgs.gov","contributorId":1028,"corporation":false,"usgs":true,"family":"Tuttle","given":"Michele L.","email":"mtuttle@usgs.gov","affiliations":[{"id":211,"text":"Crustal Geophysics and Geochemistry Science Center","active":true,"usgs":true}],"preferred":false,"id":376371,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Rice, Cynthia A.","contributorId":87140,"corporation":false,"usgs":true,"family":"Rice","given":"Cynthia","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":376374,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Fishman, Neil S.","contributorId":245198,"corporation":false,"usgs":false,"family":"Fishman","given":"Neil S.","affiliations":[{"id":49112,"text":"PetroLogic Solutions, LLC","active":true,"usgs":false}],"preferred":false,"id":376370,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Karachewski, John A.","contributorId":46070,"corporation":false,"usgs":true,"family":"Karachewski","given":"John","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":376369,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Sherman, David M.","contributorId":73218,"corporation":false,"usgs":true,"family":"Sherman","given":"David","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":376372,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70017502,"text":"70017502 - 1994 - Rare earth element contents and multiple mantle sources of the transform-related Mount Edgecumbe basalts, southeastern Alaska","interactions":[],"lastModifiedDate":"2021-04-22T19:55:17.120806","indexId":"70017502","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1168,"text":"Canadian Journal of Earth Sciences","active":true,"publicationSubtype":{"id":10}},"title":"Rare earth element contents and multiple mantle sources of the transform-related Mount Edgecumbe basalts, southeastern Alaska","docAbstract":"Pleistocene basalt of the Mount Edgecumbe volcanic field (MEF) is subdivided into a plagioclase type and an olivine type. Olivine basalt crops out farther inboard from the nearby Fairweather transform than plagioclase basalt. Th/La ratios of plagioclase basalt are similar to those of mid-ocean-ridge basalt (MORB), whereas those of olivine basalt are of continental affinity. The olivine basalt has higher 87Sr/86Sr ratios than the plagioclase basalt.We model rare earth element (REE) contents of the olivine basalt, which resemble those of transitional MORB, by 10–15% partial melting of fertile spinel–plagioclase lherzolite followed by removal of 8–13% olivine. Normative mineralogy indicates melting in the spinel stability field. REE contents of an undersaturated basalt (sample 5L005) resemble those of Mauna Loa tholeiite and are modelled by 5–10% partial melting of fertile garnet lherzolite followed by 10% olivine removal. Plagioclase basalt resembles sample 5L005 in REE contents but is lower in other incompatible-element contents and 87Sr/86Sr ratios. Plagioclase basalt either originated in depleted garnet lherzolite or is a mixture of sample 5L005 and normal MORB; complex zoning of plagioclase and colinear Sc and Th contents are consistent with magma mixing.We conclude that olivine basalt originated in subcontinental spinel lherzolite and that plagioclase basalt may have originated in suboceanic lithosphere of the Pacific plate. Lithospheric melting seemingly requires vertical flow of mantle material, although there is no direct evidence at the MEF for crustal extension that might provide a mechanism for mantle advection. In any case, most MEF magmas are subalkaline because of moderately high degrees of partial melting at shallow depth.
","language":"English","publisher":"Canadian Science Publishing","doi":"10.1139/e94-078","usgsCitation":"Riehle, J., Budahn, J., Lanphere, M.A., and Brew, D.A., 1994, Rare earth element contents and multiple mantle sources of the transform-related Mount Edgecumbe basalts, southeastern Alaska: Canadian Journal of Earth Sciences, v. 31, no. 5, p. 852-864, https://doi.org/10.1139/e94-078.","productDescription":"13 p.","startPage":"852","endPage":"864","costCenters":[{"id":615,"text":"Volcano Hazards Program","active":true,"usgs":true}],"links":[{"id":228376,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Alaska","otherGeospatial":"Kruzof Island, Mount Edgecumbe Volcanic Field","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -136.153564453125,\n 56.772293472653445\n ],\n [\n -134.98489379882812,\n 56.772293472653445\n ],\n [\n -134.98489379882812,\n 57.36579294673093\n ],\n [\n -136.153564453125,\n 57.36579294673093\n ],\n [\n -136.153564453125,\n 56.772293472653445\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"31","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a9519e4b0c8380cd817df","contributors":{"authors":[{"text":"Riehle, J.R.","contributorId":73573,"corporation":false,"usgs":true,"family":"Riehle","given":"J.R.","affiliations":[],"preferred":false,"id":376673,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Budahn, J. R. 0000-0001-9794-8882","orcid":"https://orcid.org/0000-0001-9794-8882","contributorId":83914,"corporation":false,"usgs":true,"family":"Budahn","given":"J. R.","affiliations":[],"preferred":false,"id":376674,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Lanphere, M. A.","contributorId":35298,"corporation":false,"usgs":true,"family":"Lanphere","given":"M.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":376672,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Brew, D. A.","contributorId":88344,"corporation":false,"usgs":true,"family":"Brew","given":"D.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":376675,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70017527,"text":"70017527 - 1994 - Statistical forecasting of repetitious dome failures during the waning eruption of Redoubt Volcano, Alaska, February-April 1990","interactions":[],"lastModifiedDate":"2012-03-12T17:19:59","indexId":"70017527","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2499,"text":"Journal of Volcanology and Geothermal Research","active":true,"publicationSubtype":{"id":10}},"title":"Statistical forecasting of repetitious dome failures during the waning eruption of Redoubt Volcano, Alaska, February-April 1990","docAbstract":"The waning phase of the 1989-1990 eruption of Redoubt Volcano in the Cook Inlet region of south-central Alaska comprised a quasi-regular pattern of repetitious dome growth and destruction that lasted from February 15 to late April 1990. The dome failures produced ash plumes hazardous to airline traffic. In response to this hazard, the Alaska Volcano Observatory sought to forecast these ash-producing events using two approaches. One approach built on early successes in issuing warnings before major eruptions on December 14, 1989 and January 2, 1990. These warnings were based largely on changes in seismic activity related to the occurrence of precursory swarms of long-period seismic events. The search for precursory swarms of long-period seismicity was continued through the waning phase of the eruption and led to warnings before tephra eruptions on March 23 and April 6. The observed regularity of dome failures after February 15 suggested that a statistical forecasting method based on a constant-rate failure model might also be successful. The first statistical forecast was issued on March 16 after seven events had occurred, at an average interval of 4.5 days. At this time, the interval between dome failures abruptly lengthened. Accordingly, the forecast was unsuccessful and further forecasting was suspended until the regularity of subsequent failures could be confirmed. Statistical forecasting resumed on April 12, after four dome failure episodes separated by an average of 7.8 days. One dome failure (April 15) was successfully forecast using a 70% confidence window, and a second event (April 21) was narrowly missed before the end of the activity. The cessation of dome failures after April 21 resulted in a concluding false alarm. Although forecasting success during the eruption was limited, retrospective analysis shows that early and consistent application of the statistical method using a constant-rate failure model and a 90% confidence window could have yielded five successful forecasts and two false alarms; no events would have been missed. On closer examination, the intervals between successive dome failures are not uniform but tend to increase with time. This increase attests to the continuous, slowly decreasing supply of magma to the surface vent during the waning phase of the eruption. The domes formed in a precarious position in a breach in the summit crater rim where they were susceptible to gravitational collapse. The instability of the February 15-April 21 domes relative to the earlier domes is attributed to reaming the lip of the vent by a laterally directed explosion during the major dome-destroying eruption of February 15, a process which would leave a less secure foundation for subsequent domes. ?? 1994.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Volcanology and Geothermal Research","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"03770273","usgsCitation":"Page, R., Lahr, J., Chouet, B., Power, J., and Stephens, C., 1994, Statistical forecasting of repetitious dome failures during the waning eruption of Redoubt Volcano, Alaska, February-April 1990: Journal of Volcanology and Geothermal Research, v. 62, no. 1-4, p. 183-196.","startPage":"183","endPage":"196","numberOfPages":"14","costCenters":[],"links":[{"id":228847,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"62","issue":"1-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b972de4b08c986b31b915","contributors":{"authors":[{"text":"Page, R.A.","contributorId":40197,"corporation":false,"usgs":true,"family":"Page","given":"R.A.","email":"","affiliations":[],"preferred":false,"id":376741,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Lahr, J.C.","contributorId":34892,"corporation":false,"usgs":true,"family":"Lahr","given":"J.C.","email":"","affiliations":[],"preferred":false,"id":376740,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Chouet, B. A.","contributorId":31813,"corporation":false,"usgs":true,"family":"Chouet","given":"B. A.","affiliations":[],"preferred":false,"id":376739,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Power, J.A.","contributorId":20765,"corporation":false,"usgs":true,"family":"Power","given":"J.A.","email":"","affiliations":[],"preferred":false,"id":376738,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Stephens, C.D.","contributorId":18752,"corporation":false,"usgs":true,"family":"Stephens","given":"C.D.","email":"","affiliations":[],"preferred":false,"id":376737,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70017537,"text":"70017537 - 1994 - An inverted metamorphic field gradient in the central Brooks Range, Alaska and implications for exhumation of high-pressure/low-temperature metamorphic rocks","interactions":[],"lastModifiedDate":"2013-02-22T20:23:51","indexId":"70017537","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2588,"text":"LITHOS","active":true,"publicationSubtype":{"id":10}},"title":"An inverted metamorphic field gradient in the central Brooks Range, Alaska and implications for exhumation of high-pressure/low-temperature metamorphic rocks","docAbstract":"During exhumation of the Brooks Range internal zone, amphibolite-facies rocks were emplaced atop the blueschist/greenschist facies schist belt. The resultant inverted metamorphic field gradient is mappable as a series of isograds encountered as one traverses up structural section. Amphibolite-facies metamorphism occurred at ??? 110 Ma as determined from 40Ar 39Ar analysis of hornblende. This contrasts with 40Ar 39Ar phengite cooling ages from the uderlying schist belt, which are clearly older (by 17-22 m.y.). Fabrics in both the amphibolite-facies rocks and schist belt are characterized by repeated cycles of N-vergent crenulation and transposition that was likely associated with out-of-sequence ductile thrusting in the internal zone of the Brooks Range orogen. Contractional deformation occurred in an overall environment of foreland-directed tectonic transport, broadly synchronous with exhumation of the internal zone, and shortening within the thin-skinned fold and thrust belt. These data are inconsistent with a recently postulated mid-Cretaceous episode of lithospheric extension in northern Alaska. ?? 1994.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"LITHOS","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","doi":"10.1016/0024-4937(94)90054-X","issn":"00244937","usgsCitation":"Patrick, B., Till, A., and Dinklage, W., 1994, An inverted metamorphic field gradient in the central Brooks Range, Alaska and implications for exhumation of high-pressure/low-temperature metamorphic rocks: LITHOS, v. 33, no. 1-3, p. 67-83, https://doi.org/10.1016/0024-4937(94)90054-X.","startPage":"67","endPage":"83","numberOfPages":"17","costCenters":[],"links":[{"id":228982,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":267959,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/0024-4937(94)90054-X"}],"volume":"33","issue":"1-3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059ea8ee4b0c8380cd4893c","contributors":{"authors":[{"text":"Patrick, B.","contributorId":84098,"corporation":false,"usgs":true,"family":"Patrick","given":"B.","email":"","affiliations":[],"preferred":false,"id":376793,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Till, A.B.","contributorId":37755,"corporation":false,"usgs":true,"family":"Till","given":"A.B.","email":"","affiliations":[],"preferred":false,"id":376791,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Dinklage, W.S.","contributorId":55595,"corporation":false,"usgs":true,"family":"Dinklage","given":"W.S.","email":"","affiliations":[],"preferred":false,"id":376792,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70017541,"text":"70017541 - 1994 - Classification properties of Holocene sediment in Shelikof Strait, Alaska","interactions":[],"lastModifiedDate":"2013-02-24T19:07:36","indexId":"70017541","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2669,"text":"Marine Georesources and Geotechnology","active":true,"publicationSubtype":{"id":10}},"title":"Classification properties of Holocene sediment in Shelikof Strait, Alaska","docAbstract":"A textural sorting pattern is evident, with pronounced and regular changes in sand content throughout the strait but with consistent separation of silt from clay only at the lowest sand contents. Vane shear strength values fall in the very soft to medium range. They are best predicted by the amount of silt-size grains (an indicator of mean grain size). -from Author","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Marine Georesources and Geotechnology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Taylor and Francis","doi":"10.1080/10641199409388265","usgsCitation":"Hampton, M.A., 1994, Classification properties of Holocene sediment in Shelikof Strait, Alaska: Marine Georesources and Geotechnology, v. 12, no. 3, p. 237-257, https://doi.org/10.1080/10641199409388265.","startPage":"237","endPage":"257","numberOfPages":"21","costCenters":[],"links":[{"id":229030,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":268180,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1080/10641199409388265"}],"volume":"12","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f630e4b0c8380cd4c5e2","contributors":{"authors":[{"text":"Hampton, M. A.","contributorId":103271,"corporation":false,"usgs":true,"family":"Hampton","given":"M.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":376804,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70017553,"text":"70017553 - 1994 - Precursory swarms of long-period events at Redoubt Volcano (1989-1990), Alaska: Their origin and use as a forecasting tool","interactions":[],"lastModifiedDate":"2019-04-08T10:06:22","indexId":"70017553","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2499,"text":"Journal of Volcanology and Geothermal Research","active":true,"publicationSubtype":{"id":10}},"title":"Precursory swarms of long-period events at Redoubt Volcano (1989-1990), Alaska: Their origin and use as a forecasting tool","docAbstract":"During the eruption of Redoubt Volcano from December 1989 through April 1990, the Alaska Volcano Observatory issued advance warnings of several tephra eruptions based on changes in seismic activity related to the occurrence of precursory swarms of long-period (LP) seismic events (dominant period of about 0.5 s). The initial eruption on December 14 occurred after 23 years of quiescence and was heralded by a 23-hour swarm of LP events that ended abruptly with the eruption. After a series of vent-clearing explosions over the next few days, dome growth began on December 21. Another swarm, with LP events similar to those of the first, began on the 26th and ended in a major tephra eruption on January 2. Eruptions continued over the next two weeks and then ceased until February 15, when a large eruption initiated a long phase of repetitive dome-building and dome-destroying episodes that continued into April. Warnings were issued before the major events on December 14 and January 2, but as the eruptive sequence continued after January 2, the energy of the swarms decreased and forecasting became more difficult. A significant but less intense swarm preceded the February 15 eruption, which was not forecast. This eruption destroyed the only seismograph on the volcanic edifice and stymied forecasting until March 4, when the first of three new stations was installed within 3 km of the active vent. From March 4 to the end of the sequence on April 21, there were eight eruptions, six of which were preceded by detectable swarms of LP events. Although weak, these swarms provided the basis for warnings issued before the eruptions on March 23 and April 6. The initial swarm on December 13 had the following features: (1) short duration (23 hours); (2) a rapidly accelerating rate of seismic energy release over the first 18 hours of the swarm, followed by a decline of activity during the 5 hours preceding the eruption; (3) a magnitude range from −0.4 to 1.6; (4) nearly identical LP signatures with a dominant period near 0.5 s; (5) dilatational first motions everywhere; and (6) a stationary source location at a depth of 1.4 km beneath the crater. This occurrence of long-period events suggests a model involving the interaction of magma with groundwater in which magmatic gases, steam and water drive a fixed conduit at a stationary point throughout the swarm. The initiation of that sequence of events is analogous to the failure of a pressure-relief valve connecting a lower, supercharged magma-dominated reservoir to a shallow hydrothermal system. A three-dimensional model of a vibrating fluid-filled crack recently developed by Chouet is found to be compatible with the seismic data and yields the following parameters for the LP source: crack length, 280–380 m; crack width, 140–190 m; crack thickness, 0.05–0.20 m; crack stiffness, 100–200; sound speed of fluid, 0.8–1.3 km/s; compressional-wave speed of rock, 5.1 km/s; density ratio of fluid to rock, ≈0.4; and ratio of bulk modulus of fluid to rigidity of rock, 0.03–0.07. The fluid-filled crack is excited intermittently by an impulsive pressure drop that varies in magnitude within the range of 0.4 to 40 bar. Such disturbance appears to be consistent with a triggering mechanism associated with choked flow conditions in the crack.
","language":"English","publisher":"Elsevier","doi":"10.1016/0377-0273(94)90030-2","issn":"03770273","usgsCitation":"Chouet, B., Page, R., Stephens, C., Lahr, J., and Power, J., 1994, Precursory swarms of long-period events at Redoubt Volcano (1989-1990), Alaska: Their origin and use as a forecasting tool: Journal of Volcanology and Geothermal Research, v. 62, no. 1-4, p. 95-135, https://doi.org/10.1016/0377-0273(94)90030-2.","productDescription":"41 p.","startPage":"95","endPage":"135","costCenters":[{"id":615,"text":"Volcano Hazards Program","active":true,"usgs":true}],"links":[{"id":228517,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Alaska","otherGeospatial":"Cook inlet, Redoubt Volcano","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -154,\n 59\n ],\n [\n -149,\n 59\n ],\n [\n -149,\n 62\n ],\n [\n -154,\n 62\n ],\n [\n -154,\n 59\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"62","issue":"1-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a814de4b0c8380cd7b470","contributors":{"authors":[{"text":"Chouet, B. A.","contributorId":31813,"corporation":false,"usgs":true,"family":"Chouet","given":"B. A.","affiliations":[],"preferred":false,"id":376847,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Page, R.A.","contributorId":40197,"corporation":false,"usgs":true,"family":"Page","given":"R.A.","email":"","affiliations":[],"preferred":false,"id":376849,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Stephens, C.D.","contributorId":18752,"corporation":false,"usgs":true,"family":"Stephens","given":"C.D.","email":"","affiliations":[],"preferred":false,"id":376845,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Lahr, J.C.","contributorId":34892,"corporation":false,"usgs":true,"family":"Lahr","given":"J.C.","email":"","affiliations":[],"preferred":false,"id":376848,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Power, J.A.","contributorId":20765,"corporation":false,"usgs":true,"family":"Power","given":"J.A.","email":"","affiliations":[],"preferred":false,"id":376846,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70017554,"text":"70017554 - 1994 - The geologic history of Redoubt Volcano, Alaska","interactions":[],"lastModifiedDate":"2012-03-12T17:19:54","indexId":"70017554","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2499,"text":"Journal of Volcanology and Geothermal Research","active":true,"publicationSubtype":{"id":10}},"title":"The geologic history of Redoubt Volcano, Alaska","docAbstract":"Redoubt Volcano is a composite cone built on continental crust at the northeast end of the Aleutian arc. Magmas erupted at Redoubt are medium-K calc-alkaline basalts, andesites, and dacites. The eruptive history of the volcano can be divided into four parts: the early explosive stage, early cone-building stage, late cone-building stage, and post-glacial stage. The most silicic products of the volcano were erupted during the early explosive stage about 0.888 Ma and include pumiceous pyroclastic flow deposits, block-and-ash flow deposits, and a dome or shallow intrusive complex. Basalt and basaltic andesite lava flows and scoria and ash flows were produced during the early cone-building stage, which was underway by 0.340 Ma. During the late cone-building stage, andesitic lava flows and block-and-ash flows were emplaced. Airfall deposits produced during post-glacial eruptions are silicic andesite in composition. Since the early cone-building stage, magmas have become progressively more silicic, but none are as silicic as those in the early explosive stage. Limited Pb and Sr isotopic data suggest that Redoubt magmas were contaminated by North American continental crust. ?? 1994.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Volcanology and Geothermal Research","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"03770273","usgsCitation":"Till, A., Yount, M.E., and Bevier, M., 1994, The geologic history of Redoubt Volcano, Alaska: Journal of Volcanology and Geothermal Research, v. 62, no. 1-4, p. 11-30.","startPage":"11","endPage":"30","numberOfPages":"20","costCenters":[],"links":[{"id":228518,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"62","issue":"1-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bac56e4b08c986b323427","contributors":{"authors":[{"text":"Till, A.B.","contributorId":37755,"corporation":false,"usgs":true,"family":"Till","given":"A.B.","email":"","affiliations":[],"preferred":false,"id":376850,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Yount, M. E.","contributorId":76748,"corporation":false,"usgs":true,"family":"Yount","given":"M.","middleInitial":"E.","affiliations":[],"preferred":false,"id":376851,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Bevier, M.L.","contributorId":80964,"corporation":false,"usgs":true,"family":"Bevier","given":"M.L.","email":"","affiliations":[],"preferred":false,"id":376852,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70017560,"text":"70017560 - 1994 - The 1989-1990 eruption of Redoubt Volcano, Alaska: impacts on aircraft operations","interactions":[],"lastModifiedDate":"2019-04-08T10:04:12","indexId":"70017560","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2499,"text":"Journal of Volcanology and Geothermal Research","active":true,"publicationSubtype":{"id":10}},"title":"The 1989-1990 eruption of Redoubt Volcano, Alaska: impacts on aircraft operations","docAbstract":"The December 1989–June 1990 eruption of Redoubt Volcano affected commercial and military air operations in the vicinity of Anchorage, Alaska. These effects were due to the direct impact of volcanic ash on jet aircraft, as well as to the rerouting and cancellations of flight operations owing to eruptive activity. Between December and February, five commercial jetliners were damaged from ash encounters. The most serious incident took place on December 15, 1989 when a Boeing 747-400 aircraft temporarily lost power of all four engines after encountering an ash cloud as the airplane descended for a landing in Anchorage. While there were no injuries to passengers, the damage to engines, avionics, and aircraft structure from this encounter is estimated at $80 million. Four additional encounters between jet aircraft and Redoubt ash clouds occurred in the Anchorage area on December 15 and 16, 1989 and February 21, 1990; none resulted in engine failure. Two additional encounters took place on December 17, 1989 when jet airliners encountered the Redoubt cloud over west Texas. At the time of these encounters, the cloud was up to 55 hours old and had traveled in excess of 2,900 nautical miles (5,300 km).
Following the December 15 encounters, Anchorage International Airport remained open, however, most airline companies canceled operations for up to several days. As communications between Federal agencies and airlines improved, and as a better understanding of the nature and behavior of ash-rich eruption clouds was achieved, most airlines resumed normal service by early January 1990. The resulting loss of revenue at Anchorage International Airport during several months following the eruption is estimated to total $2.6 million. The impact on general aviation and military operations consisted mostly of cancellation and rerouting of flights.
","language":"English","publisher":"Elsevier","doi":"10.1016/0377-0273(94)90038-8","issn":"03770273","usgsCitation":"Casadevall, T.J., 1994, The 1989-1990 eruption of Redoubt Volcano, Alaska: impacts on aircraft operations: Journal of Volcanology and Geothermal Research, v. 62, no. 1-4, p. 301-316, https://doi.org/10.1016/0377-0273(94)90038-8.","productDescription":"16 p.","startPage":"301","endPage":"316","costCenters":[{"id":615,"text":"Volcano Hazards Program","active":true,"usgs":true}],"links":[{"id":228660,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Alaska","otherGeospatial":"Cook inlet, Redoubt Volcano","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -154,\n 59\n ],\n [\n -149,\n 59\n ],\n [\n -149,\n 62\n ],\n [\n -154,\n 62\n ],\n [\n -154,\n 59\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"62","issue":"1-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505ba62ee4b08c986b320f46","contributors":{"authors":[{"text":"Casadevall, T. J.","contributorId":96680,"corporation":false,"usgs":true,"family":"Casadevall","given":"T.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":376867,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70017564,"text":"70017564 - 1994 - Pliocene terrace gravels of the ancestral Yukon River near Circle, Alaska: Palynology, paleobotany, paleoenvironmental reconstruction and regional correlation","interactions":[],"lastModifiedDate":"2013-03-25T16:39:38","indexId":"70017564","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3217,"text":"Quaternary International","active":true,"publicationSubtype":{"id":10}},"title":"Pliocene terrace gravels of the ancestral Yukon River near Circle, Alaska: Palynology, paleobotany, paleoenvironmental reconstruction and regional correlation","docAbstract":"Gravels deposited by the ancestral Yukon River are preserved in terrace remnants on the margins of the Yukon River valley near the village of Circle in east-central Alaska. Plant fossils recovered from sandy silt lenses within these gravels include cones and needles of Picea and Larix and a variety of seeds. Seed types include several taxa which no longer grow in Alaska, such as Epipremnum, Prunus and Weigela. Pollen types recovered from these deposits represent tree and shrub taxa that grow in interior Alaska today, such as Picea, Larix, Betula and Alnus, as well as several taxa that no longer grow in interior Alaska today, such as Pinus, Tsuga, Abies and Corylus. Pollen of herb taxa identified include Gramineae, Cyperaceae, Caryophyllaceae, Compositae, Polemonium and Epilobium. The fossil flora from the gravels near Circle are similar and probably age-equivalent to the flora recovered from the Nenana Gravel in the Alaska Range 250 km to the south. Palynological and tectonic evidence summarized in this paper now suggests that the Nenana Gravel was deposited during the early and middle Pliocene. The presence of plant fossils of Tsuga, Abies, Pinus, Weigela and Prunus suggests that the mean annual temperature (MAT) of eastern interior Alaska during the early and middle Pliocene was perhaps 7-9??C warmer and less continental than today's MAT of -6.4??C. ?? 1994.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Quaternary International","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","doi":"10.1016/1040-6182(94)90012-4","issn":"10406182","usgsCitation":"Ager, T.A., Matthews, J., and Yeend, W., 1994, Pliocene terrace gravels of the ancestral Yukon River near Circle, Alaska: Palynology, paleobotany, paleoenvironmental reconstruction and regional correlation: Quaternary International, v. 22-23, no. C, p. 185-206, https://doi.org/10.1016/1040-6182(94)90012-4.","startPage":"185","endPage":"206","numberOfPages":"22","costCenters":[],"links":[{"id":270058,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/1040-6182(94)90012-4"},{"id":228711,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"22-23","issue":"C","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a7c7ee4b0c8380cd799f7","contributors":{"authors":[{"text":"Ager, T. A.","contributorId":88386,"corporation":false,"usgs":true,"family":"Ager","given":"T.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":376878,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Matthews, J.V. Jr.","contributorId":72931,"corporation":false,"usgs":true,"family":"Matthews","given":"J.V.","suffix":"Jr.","email":"","affiliations":[],"preferred":false,"id":376877,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Yeend, W.","contributorId":88898,"corporation":false,"usgs":true,"family":"Yeend","given":"W.","affiliations":[],"preferred":false,"id":376879,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70017585,"text":"70017585 - 1994 - Disruption of Drift glacier and origin of floods during the 1989-1990 eruptions of Redoubt Volcano, Alaska","interactions":[],"lastModifiedDate":"2021-01-18T22:16:00.306289","indexId":"70017585","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2499,"text":"Journal of Volcanology and Geothermal Research","active":true,"publicationSubtype":{"id":10}},"title":"Disruption of Drift glacier and origin of floods during the 1989-1990 eruptions of Redoubt Volcano, Alaska","docAbstract":"Melting of snow and glacier ice during the 1989–1990 eruption of Redoubt Volcano caused winter flooding of the Drift River. Drift glacier was beheaded when 113 to 121 × 106 m3 of perennial snow and ice were mechanically entrained in hot-rock avalanches and pyroclastic flows initiated by the four largest eruptions between 14 December 1989 and 14 March 1990. The disruption of Drift glacier was dominated by mechanical disaggregation and entrainment of snow and glacier ice. Hot-rock avalanches, debris flows, and pyroclastic flows incised deep canyons in the glacier ice thereby maintaining a large ice-surface area available for scour by subsequent flows. Downvalley flow rheologies were transformed by the melting of snow and ice entrained along the upper and middle reaches of the glacier and by seasonal snowpack incorporated from the surface of the lower glacier and from the river valley. The seasonal snowpack in the Drift River valley contributed to lahars and floods a cumulative volume equivalent to about 35 × 106 m3 of water, which amounts to nearly 30% of the cumulative flow volume 22 km downstream from the volcano. The absence of high-water marks in depressions and of ice-collapse features in the glacier indicated that no large quantities of meltwater that could potentially generate lahars were stored on or under the glacier; the water that generated the lahars that swept Drift River valley was produced from the proximal, eruption-induced volcaniclastic flows by melting of snow and ice.
","language":"English","publisher":"Elsevier","doi":"10.1016/0377-0273(94)90043-4","usgsCitation":"Trabant, D., Waitt, R., and Major, J., 1994, Disruption of Drift glacier and origin of floods during the 1989-1990 eruptions of Redoubt Volcano, Alaska: Journal of Volcanology and Geothermal Research, v. 62, no. 1-4, p. 369-385, https://doi.org/10.1016/0377-0273(94)90043-4.","productDescription":"17 p.","startPage":"369","endPage":"385","numberOfPages":"17","costCenters":[{"id":157,"text":"Cascades Volcano Observatory","active":false,"usgs":true}],"links":[{"id":229032,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Alaska","otherGeospatial":"Redoubt Volcano","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -153.5723876953125,\n 60.18659839709946\n ],\n [\n -152.28424072265625,\n 60.18659839709946\n ],\n [\n -152.28424072265625,\n 60.788662338870736\n ],\n [\n -153.5723876953125,\n 60.788662338870736\n ],\n [\n -153.5723876953125,\n 60.18659839709946\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"62","issue":"1-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0224e4b0c8380cd4fedc","contributors":{"authors":[{"text":"Trabant, D.C.","contributorId":42209,"corporation":false,"usgs":true,"family":"Trabant","given":"D.C.","email":"","affiliations":[],"preferred":false,"id":376921,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Waitt, R. B.","contributorId":78766,"corporation":false,"usgs":true,"family":"Waitt","given":"R. B.","affiliations":[],"preferred":false,"id":376922,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Major, J. J. 0000-0003-2449-4466","orcid":"https://orcid.org/0000-0003-2449-4466","contributorId":29461,"corporation":false,"usgs":true,"family":"Major","given":"J. J.","affiliations":[{"id":157,"text":"Cascades Volcano Observatory","active":false,"usgs":true}],"preferred":true,"id":376920,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70017621,"text":"70017621 - 1994 - Composition and sources of atmospheric dusts in snow at 3200 meters in the St. Elias Range, southeastern Alaska, USA","interactions":[],"lastModifiedDate":"2023-12-21T23:44:20.657511","indexId":"70017621","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1759,"text":"Geochimica et Cosmochimica Acta","active":true,"publicationSubtype":{"id":10}},"title":"Composition and sources of atmospheric dusts in snow at 3200 meters in the St. Elias Range, southeastern Alaska, USA","docAbstract":"Dusts in snow from the accumulation zone in the St. Elias Range appear from their chemical compositions to have come from terranes of rocks of ferromagnesian composition. These dusts, with respect to their composition and to the moderate degree of variation that occurs through a depositional year, are similar those deposited in Greenland. The high portion of the St. Elias Range is isolated from dominance by any local dust source terranes, because of altitude and the extent of the surrounding glacierized and snow-covered region. In Greenland the altitude is typically lower, but local sources are even less likely to dominate the character of the dusts deposited into the ice record there. The similar compositions and moderate compositional variations of dusts from these two places bear on the question of whether the dusts that are transported over long distances by the atmosphere under modern and glacial-period conditions are uniform and representative of a broad regional or even hemispheric background dust.
The dusts in the snow were measured by means of a suite of major, minor, and trace rock-forming metals chosen to give information about rock types, their constituent minerals, degree of degradation (weathering), and energies of atmospheric uptake from source. The variations in amounts of rock dust through the year in the St. Elias Range snowpack have no time-stratigraphic correspondence to the also large variations in concentrations of other species that are not constituents of rock-derived dusts, such the anions chloride, sulfate, and nitrate; the highs and lows of the two types of materials are apparently completely independent. The structure revealed by the moderately fine-scale sampling of the present study (≈ 10 increments/y) serves as a background for the interpretation of analysis of ice core samples, in which annual layers may be too compressed to permit analysis of sub-annual samples.
","language":"English","publisher":"Elsevier","doi":"10.1016/0016-7037(94)90052-3","issn":"00167037","usgsCitation":"Hinkley, T.K., 1994, Composition and sources of atmospheric dusts in snow at 3200 meters in the St. Elias Range, southeastern Alaska, USA: Geochimica et Cosmochimica Acta, v. 58, no. 15, p. 3245-3254, https://doi.org/10.1016/0016-7037(94)90052-3.","productDescription":"10 p.","startPage":"3245","endPage":"3254","numberOfPages":"10","costCenters":[],"links":[{"id":228987,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Alaska","otherGeospatial":"St. Elias Mountains","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -141.0032175389977,\n 62.210218220064775\n ],\n [\n -142.25737287078866,\n 62.52837725040516\n ],\n [\n -142.93268728021445,\n 62.55803188684837\n ],\n [\n -143.28642339943755,\n 62.543208260917964\n ],\n [\n -143.57584386062007,\n 62.468979308849526\n ],\n [\n -143.84382576912233,\n 62.5629714549375\n ],\n [\n -144.37978958612703,\n 62.53826541138886\n ],\n [\n -144.37978958612703,\n 62.39953209436908\n ],\n [\n -144.85143774509115,\n 62.2451814135363\n ],\n [\n -145.04581690140432,\n 62.060587689027614\n ],\n [\n -144.7028000585214,\n 61.80842879627835\n ],\n [\n -144.4133795973389,\n 61.554182356561824\n ],\n [\n -144.48841453171954,\n 61.400627378021994\n ],\n [\n -144.77783499290206,\n 61.333851468260576\n ],\n [\n -144.86358920362275,\n 61.2308406709472\n ],\n [\n -144.9171855853233,\n 61.14818841004384\n ],\n [\n -144.8207120982624,\n 61.0860568405875\n ],\n [\n -144.64920367682086,\n 60.909353116445885\n ],\n [\n -144.55273018976013,\n 60.81540557684656\n ],\n [\n -144.71351933486147,\n 60.66871493381268\n ],\n [\n -144.79927354558214,\n 60.500246181077415\n ],\n [\n -144.7885542692421,\n 60.224605947856645\n ],\n [\n -144.4776952553795,\n 60.1286481115946\n ],\n [\n -144.27402900491765,\n 60.14999630716653\n ],\n [\n -143.7809422932733,\n 60.26716394261496\n ],\n [\n -143.3200134106494,\n 60.229928721682825\n ],\n [\n -142.48390985612212,\n 60.06452035345387\n ],\n [\n -142.18377011859957,\n 60.02169914497688\n ],\n [\n -141.6585255779349,\n 59.94662832953182\n ],\n [\n -140.9296147868086,\n 60.02169914497688\n ],\n [\n -140.62947504928601,\n 60.096599832812785\n ],\n [\n -140.31861603542325,\n 60.00562687240904\n ],\n [\n -139.76121366573847,\n 59.83370255451186\n ],\n [\n -139.4289160991956,\n 60.02705483304442\n ],\n [\n -139.16093419069315,\n 60.10728605813418\n ],\n [\n -139.07517997997246,\n 60.293734617155565\n ],\n [\n -139.07517997997246,\n 60.35741621298649\n ],\n [\n -139.69689800769785,\n 60.34150745817661\n ],\n [\n -139.97559919254033,\n 60.197979110526376\n ],\n [\n -140.45796662784448,\n 60.3149756187629\n ],\n [\n -140.53300156222514,\n 60.23525063118228\n ],\n [\n -140.98321116850897,\n 60.3149756187629\n ],\n [\n -141.0032175389977,\n 62.210218220064775\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"58","issue":"15","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f921e4b0c8380cd4d456","contributors":{"authors":[{"text":"Hinkley, T. K. 0000-0001-8507-6271","orcid":"https://orcid.org/0000-0001-8507-6271","contributorId":78731,"corporation":false,"usgs":true,"family":"Hinkley","given":"T.","email":"","middleInitial":"K.","affiliations":[],"preferred":false,"id":377042,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70017626,"text":"70017626 - 1994 - Vapor saturation and accumulation in magmas of the 1989-1990 eruption of Redoubt Volcano, Alaska","interactions":[],"lastModifiedDate":"2016-09-07T18:00:14","indexId":"70017626","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2499,"text":"Journal of Volcanology and Geothermal Research","active":true,"publicationSubtype":{"id":10}},"title":"Vapor saturation and accumulation in magmas of the 1989-1990 eruption of Redoubt Volcano, Alaska","docAbstract":"The 1989–1990 eruption of Redoubt Volcano, Alaska, provided an opportunity to compare petrologic estimates of SO2 and Cl emissions with estimates of SO2 emissions based on remote sensing data and estimates of Cl emissions based on plume sampling. In this study, we measure the sulfur and chlorine contents of melt inclusions and matrix glasses in the eruption products to determine petrologic estimates of SO2 and Cl emissions. We compare the results with emission estimates based on COSPEC and TOMS data for SO2 and data for Cl/SO2 in plume samples. For the explosive vent clearing period (December 14–22, 1989), the petrologic estimate for SO2 emission is 21,000 tons, or ~12% of a TOMS estimate of 175,000 tons. For the dome growth period (December 22, 1989 to mid-June 1990), the petrologic estimate for SO2 emission is 18,000 tons, or ~3% of COSPEC-based estimates of 572,000–680,000 tons. The petrologic estimates give a total SO2 emission of only 39,000 tons compared to an integrated TOMS/COSPEC emission estimate of ~1,000,000 tons for the whole eruption, including quiescent degassing after mid-June 1990. Petrologic estimates also appear to underestimate Cl emissions, but apparent HCl scavenging in the plume complicates Cl emission comparisons. Several potential sources of ‘excess sulfur’ often invoked to explain petrologic SO2 deficits are concluded to be unlikely for the 1989–1990 Redoubt eruption — e.g., breakdown of sulfides, breakdown of anhydrite, release of SO2 from a hydrothermal system, degassing of commingled infusions of basalt in the magma chamber, and syn-eruptive degassing of sulfur from melt present in non-erupted magma. Leakage and/or diffusion of sulfur from melt inclusions do not provide convincing explanations for the petrologic SO2 deficits either. The main cause of low petrologic estimates for SO2 is that melt inclusions do not represent the total sulfur content of the Redoubt magmas, which were vapor-saturated magmas carrying most of their sulfur in an accumulated vapor phase. Almost all the sulfur of the SO2 emissions was present prior to emission as accumulated magmatic vapor at 6–10 km depth in the magma that supplied the eruption; whole-rock normalized concentrations of gaseous excess S in these magmas remained at ~0.2 wt.% throughout the eruption, equivalent to ~0.7 vol.% at depth. Data for CO2 emissions during the eruption indicate that CO2 at whole-rock concentrations of ~0.6 wt.% in the erupted magma was a key factor in creating the vapor saturation and accumulation condition making a vapor phase source of excess sulfur possible at depth. When explosive volcanism involves magma with accumulated vapor, melt inclusions do not provide a sufficient basis for predicting SO2 emissions. Thus, petrologic estimates made for SO2 emissions during explosive eruptions of the past may be too low and may significantly underestimate impacts on climate and the chemistry of the atmosphere.
","language":"English","publisher":"Elsevier Science","doi":"10.1016/0377-0273(94)90039-6","issn":"03770273","usgsCitation":"Gerlach, T.M., Westrich, H.R., Casadevall, T.J., and Finnegan, D., 1994, Vapor saturation and accumulation in magmas of the 1989-1990 eruption of Redoubt Volcano, Alaska: Journal of Volcanology and Geothermal Research, v. 62, no. 1-4, p. 317-337, https://doi.org/10.1016/0377-0273(94)90039-6.","productDescription":"21 p.","startPage":"317","endPage":"337","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[],"links":[{"id":228337,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"62","issue":"1-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bc11ee4b08c986b32a458","contributors":{"authors":[{"text":"Gerlach, Terrance M.","contributorId":89512,"corporation":false,"usgs":true,"family":"Gerlach","given":"Terrance","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":377060,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Westrich, Henry R.","contributorId":174450,"corporation":false,"usgs":false,"family":"Westrich","given":"Henry","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":377059,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Casadevall, Thomas J. 0000-0002-9447-6864 tcasadevall@usgs.gov","orcid":"https://orcid.org/0000-0002-9447-6864","contributorId":2734,"corporation":false,"usgs":true,"family":"Casadevall","given":"Thomas","email":"tcasadevall@usgs.gov","middleInitial":"J.","affiliations":[{"id":35995,"text":"Geology, Geophysics, and Geochemistry Science Center","active":true,"usgs":true}],"preferred":true,"id":377062,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Finnegan, David L.","contributorId":80410,"corporation":false,"usgs":true,"family":"Finnegan","given":"David L.","affiliations":[],"preferred":false,"id":377061,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70017631,"text":"70017631 - 1994 - Unusual ice diamicts emplaced during the December 15, 1989 eruption of Redoubt volcano, Alaska","interactions":[],"lastModifiedDate":"2021-01-18T22:12:00.971144","indexId":"70017631","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2499,"text":"Journal of Volcanology and Geothermal Research","active":true,"publicationSubtype":{"id":10}},"title":"Unusual ice diamicts emplaced during the December 15, 1989 eruption of Redoubt volcano, Alaska","docAbstract":"Ice diamict comprising clasts of glacier ice and subordinate rock debris in a matrix of ice (snow) grains, coarse ash, and frozen pore water was deposited during the eruption of Redoubt Volcano on December 15, 1989. Rounded clasts of glacier ice and snowpack are as large as 2.5 m, clasts of Redoubt andesite and basement crystalline rocks reach 1 m, and tabular clasts of entrained snowpack are as long as 10 m.
Ice diamict was deposited on both the north and south volcano flanks. On Redoubt's north flank along the east side of Drift piedmont glacier and outwash valley, ice diamict accumulated as at least 3 units, each 1–5 m thick. Two ice-diamict layers underlie a pumice-lithic fall tephra that accumulated on December 15 from 10:15 to 11:45 AST. A third ice diamict overlies the pumiceous tephra. Some of the ice diamicts have a basal ‘ice-sandstone’ layer. The north side icy flows reached as far as 14 km laterally over an altitude drop of 2.3 km and covered an area of about 5.7 km2. On Crescent Glacier on the south volcano flank, a composite ice diamict is locally as thick as 20 m. It travelled 4.3 km over an altitude drop of 1.7 km, covering about 1 km2. The much higher mobility of the northside flows was influenced by their much higher water contents than the southside flow(s).
Erupting hot juvenile andesite triggered and turbulently mixed with snow avalanches at snow-covered glacier heads. These flows rapidly entrained more snow, firn, and ice blocks from the crevassed glacier. On the north flank, a trailing watery phase of each ice-diamict flow swept over and terraced the new icy deposits. The last (and perhaps each) flood reworked valley-floor snowpack and swept 35 km downvalley to the sea. Ice diamict did not form during eruptions after December 15 despite intervening snowfalls. These later pyroclastic flows swept mainly over glacier ice rather than snowpack and generated laharic floods rather than snowflows.
Similar flows of mixed ice grains and pyroclastic debris resulted from the November 13, 1985 eruption of Nevado del Ruiz volcano and from eruptions of snowclad Mount St. Helens in 1982–1984. Such deposits at snowclad volcanoes are initially broad and geomorphically distinct, but they soon become extensively reworked and hard to recognize in the geologic record.
","language":"English","publisher":"Elsevier","doi":"10.1016/0377-0273(94)90045-0","usgsCitation":"Waitt, R., Gardner, C.A., Pierson, T., Major, J., and Neal, C., 1994, Unusual ice diamicts emplaced during the December 15, 1989 eruption of Redoubt volcano, Alaska: Journal of Volcanology and Geothermal Research, v. 62, no. 1-4, p. 409-428, https://doi.org/10.1016/0377-0273(94)90045-0.","productDescription":"20 p.","startPage":"409","endPage":"428","numberOfPages":"20","costCenters":[{"id":157,"text":"Cascades Volcano Observatory","active":false,"usgs":true}],"links":[{"id":228431,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Alaska","otherGeospatial":"Redoubt Volcano","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -152.8932952880859,\n 60.391808675970445\n ],\n [\n -152.6103973388672,\n 60.391808675970445\n ],\n [\n -152.6103973388672,\n 60.575500068060016\n ],\n [\n -152.8932952880859,\n 60.575500068060016\n ],\n [\n -152.8932952880859,\n 60.391808675970445\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"62","issue":"1-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bbd03e4b08c986b328e8d","contributors":{"authors":[{"text":"Waitt, R. B.","contributorId":78766,"corporation":false,"usgs":true,"family":"Waitt","given":"R. B.","affiliations":[],"preferred":false,"id":377076,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Gardner, C. A.","contributorId":75916,"corporation":false,"usgs":true,"family":"Gardner","given":"C.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":377075,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Pierson, T.C. 0000-0001-9002-4273","orcid":"https://orcid.org/0000-0001-9002-4273","contributorId":41855,"corporation":false,"usgs":true,"family":"Pierson","given":"T.C.","affiliations":[{"id":157,"text":"Cascades Volcano Observatory","active":false,"usgs":true}],"preferred":true,"id":377074,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Major, J. J. 0000-0003-2449-4466","orcid":"https://orcid.org/0000-0003-2449-4466","contributorId":29461,"corporation":false,"usgs":true,"family":"Major","given":"J. J.","affiliations":[{"id":157,"text":"Cascades Volcano Observatory","active":false,"usgs":true}],"preferred":true,"id":377073,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Neal, C.A. 0000-0002-7697-7825","orcid":"https://orcid.org/0000-0002-7697-7825","contributorId":91122,"corporation":false,"usgs":true,"family":"Neal","given":"C.A.","affiliations":[],"preferred":false,"id":377077,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70017632,"text":"70017632 - 1994 - Seismic evolution of the 1989-1990 eruption sequence of Redoubt Volcano, Alaska","interactions":[],"lastModifiedDate":"2012-03-12T17:19:55","indexId":"70017632","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2499,"text":"Journal of Volcanology and Geothermal Research","active":true,"publicationSubtype":{"id":10}},"title":"Seismic evolution of the 1989-1990 eruption sequence of Redoubt Volcano, Alaska","docAbstract":"Redoubt Volcano in south-central Alaska erupted between December 1989 and June 1990 in a sequence of events characterized by large tephra eruptions, pyroclastic flows, lahars and debris flows, and episodes of dome growth. The eruption was monitored by a network of five to nine seismic stations located 1 to 22 km from the summit crater. Notable features of the eruption seismicity include : (1) small long-period events beginning in September 1989 which increased slowly in number during November and early December; (2) an intense swarm of long-period events which preceded the initial eruptions on December 14 by 23 hours; (3) shallow swarms (0 to 3 km) of volcano-tectonic events following each eruption on December 15; (4) a persistent cluster of deep (6 to 10 km) volcano-tectonic earthquakes initiated by the eruptions on December 15, which continued throughout and beyond the eruption; (5) an intense swarm of long-period events which preceded the eruptions on January 2; and (6) nine additional intervals of increased long-period seismicity each of which preceded a tephra eruption. Hypocenters of volcano-tectonic earthquakes suggest the presence of a magma source region at 6-10 km depth. Earthquakes at these depths were initiated by the tephra eruptions on December 15 and likely represent the readjustment of stresses in the country rock associated with the removal of magma from these depths. The locations and time-history of these earthquakes coupled with the eruptive behavior of the volcano suggest this region was the source of most of the erupted material during the 1989-1990 eruption. This source region appears to be connected to the surface by a narrow pipe-like conduit as inferred from the hypocenters of volcano-tectonic earthquakes. Concentrations of shallow volcano-tectonic earthquakes followed each of the tephra eruptions on December 15; these shocks may represent stress readjustment in the wall rock related to the removal of magma and volatiles at these depths. This shallow zone was the source area of the majority of long-period seismicity through the remainder of the eruption. The long-period seismicity likely reflects the pressurization of the shallow portions of the magmatic system. ?? 1994.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Volcanology and Geothermal Research","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"03770273","usgsCitation":"Power, J., Lahr, J., Page, R., Chouet, B., Stephens, C., Harlow, D., Murray, T., and Davies, J., 1994, Seismic evolution of the 1989-1990 eruption sequence of Redoubt Volcano, Alaska: Journal of Volcanology and Geothermal Research, v. 62, no. 1-4, p. 69-94.","startPage":"69","endPage":"94","numberOfPages":"26","costCenters":[],"links":[{"id":228432,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"62","issue":"1-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b8b12e4b08c986b31757c","contributors":{"authors":[{"text":"Power, J.A.","contributorId":20765,"corporation":false,"usgs":true,"family":"Power","given":"J.A.","email":"","affiliations":[],"preferred":false,"id":377079,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Lahr, J.C.","contributorId":34892,"corporation":false,"usgs":true,"family":"Lahr","given":"J.C.","email":"","affiliations":[],"preferred":false,"id":377083,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Page, R.A.","contributorId":40197,"corporation":false,"usgs":true,"family":"Page","given":"R.A.","email":"","affiliations":[],"preferred":false,"id":377084,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Chouet, B. A.","contributorId":31813,"corporation":false,"usgs":true,"family":"Chouet","given":"B. A.","affiliations":[],"preferred":false,"id":377081,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Stephens, C.D.","contributorId":18752,"corporation":false,"usgs":true,"family":"Stephens","given":"C.D.","email":"","affiliations":[],"preferred":false,"id":377078,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Harlow, D.H.","contributorId":34533,"corporation":false,"usgs":true,"family":"Harlow","given":"D.H.","email":"","affiliations":[],"preferred":false,"id":377082,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Murray, T.L.","contributorId":30226,"corporation":false,"usgs":true,"family":"Murray","given":"T.L.","email":"","affiliations":[],"preferred":false,"id":377080,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Davies, J.N.","contributorId":95045,"corporation":false,"usgs":true,"family":"Davies","given":"J.N.","email":"","affiliations":[],"preferred":false,"id":377085,"contributorType":{"id":1,"text":"Authors"},"rank":8}]}} ,{"id":70017634,"text":"70017634 - 1994 - Emission rates of sulfur dioxide and carbon dioxide from Redoubt Volcano, Alaska during the 1989-1990 eruptions","interactions":[],"lastModifiedDate":"2012-03-12T17:19:54","indexId":"70017634","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2499,"text":"Journal of Volcanology and Geothermal Research","active":true,"publicationSubtype":{"id":10}},"title":"Emission rates of sulfur dioxide and carbon dioxide from Redoubt Volcano, Alaska during the 1989-1990 eruptions","docAbstract":"Airborne measurements of sulfur dioxide emission rates in the gas plume emitted from fumaroles in the summit crater of Redoubt Volcano were started on March 20, 1990 using the COSPEC method. During the latter half of the period of intermittent dome growth and destruction, between March 20 and mid-June 1990, sulfur dioxide emission rates ranged from approximately 1250 to 5850 t/d, rates notably higher than for other convergent-plate boundary volcanoes during periods of active dome growth. Emission rates following the end of dome growth from late June 1990 through May 1991 decreased steadily to less than 75 t/d. The largest mass of sulfur dioxide was released during the period of explosive vent clearing when explosive degassing on December 14-15 injected at least 175,000 ?? 50,000 tonnes of SO2 into the atmosphere. Following the explosive eruptions of December 1989, Redoubt Volcano entered a period of intermittent dome growth from late December 1989 to mid-June 1990 during which Redoubt emitted a total mass of SO2 ranging from 572,000 ?? 90,000 tonnes to 680,000 ?? 90,000 tonnes. From mid-June 1990 through May 1991, the volcano was in a state of posteruption degassing into the troposphere, producing approximately 183,000 ?? 50,000 tonnes of SO2. We estimate that Redoubt Volcano released a minimum mass of sulfur dioxide of approximately 930,000 tonnes. While COSPEC data were not obtained frequently enough to enable their use in eruption prediction, SO2 emission rates clearly indicated a consistent decline in emission rates between March through October 1990 and a continued low level of emission rates through the first half of 1991. Values from consecutive daily measurements of sulfur dioxide emission rates spanning the March 23, 1990 eruption decreased in the three days prior to eruption. That decrease was coincident with a several-fold increase in the frequency of shallow seismic events, suggesting partial sealing of the magma conduit to gas loss that resulted in pressurization of the shallow magma system and an increase in earthquake activity. Unlike the short-term SO2 decrease in March 1990, the long-term decrease of sulfur dioxide emission rates from March 1990 through May 1991 was coincident with low rates of seismic energy release and was interpreted to reflect gradual depressurization of the shallow magma reservoir. The long-term declines in seismic energy release and in SO2 emission rates led AVO scientists to conclude on April 19, 1991 that the potential for further eruptive activity from Redoubt Volcano had diminished, and on this basis, the level of concern color code for the volcano was changed from code yellow (Volcano is restless; earthquake activity is elevated; activity may include extrusion of lava) to code green (Volcano is in its normal 'dormant' state). ?? 1994.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Volcanology and Geothermal Research","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"03770273","usgsCitation":"Casadevall, T.J., Doukas, M., Neal, C., McGimsey, R.G., and Gardner, C.A., 1994, Emission rates of sulfur dioxide and carbon dioxide from Redoubt Volcano, Alaska during the 1989-1990 eruptions: Journal of Volcanology and Geothermal Research, v. 62, no. 1-4, p. 519-530.","startPage":"519","endPage":"530","numberOfPages":"12","costCenters":[],"links":[{"id":228476,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"62","issue":"1-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a08fbe4b0c8380cd51d41","contributors":{"authors":[{"text":"Casadevall, T. J.","contributorId":96680,"corporation":false,"usgs":true,"family":"Casadevall","given":"T.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":377092,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Doukas, M.P.","contributorId":28615,"corporation":false,"usgs":true,"family":"Doukas","given":"M.P.","email":"","affiliations":[],"preferred":false,"id":377088,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Neal, C.A. 0000-0002-7697-7825","orcid":"https://orcid.org/0000-0002-7697-7825","contributorId":91122,"corporation":false,"usgs":true,"family":"Neal","given":"C.A.","affiliations":[],"preferred":false,"id":377090,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"McGimsey, R. G.","contributorId":93921,"corporation":false,"usgs":true,"family":"McGimsey","given":"R.","email":"","middleInitial":"G.","affiliations":[],"preferred":false,"id":377091,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Gardner, C. A.","contributorId":75916,"corporation":false,"usgs":true,"family":"Gardner","given":"C.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":377089,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70017644,"text":"70017644 - 1994 - Proximal pyroclastic deposits from the 1989-1990 eruption of Redoubt Volcano, Alaska - stratigraphy, distribution, and physical characteristics","interactions":[],"lastModifiedDate":"2012-03-12T17:19:54","indexId":"70017644","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2499,"text":"Journal of Volcanology and Geothermal Research","active":true,"publicationSubtype":{"id":10}},"title":"Proximal pyroclastic deposits from the 1989-1990 eruption of Redoubt Volcano, Alaska - stratigraphy, distribution, and physical characteristics","docAbstract":"More than 20 eruptive events during the 1989-1990 eruption of Redoubt Volcano emplaced a complex sequence of lithic pyroclastic-flow, -surge, -fall, ice-diamict, and lahar deposits mainly on the north side of the volcano. The deposits record the changing eruption dynamics from initial gas-rich vent-clearing explosions to episodic gas-poor lava-dome extrusions and failures. The repeated dome failures produced lithic pyroclastic flows that mixed with snow and glacial ice to generate lahars that were channelled off Drift glacier into the Drift River valley. Some of the dome failures occurred without precursory seismic warning and appeared to result solely from gravitational instability. Material from the disrupted lava domes avalanched down a steep, partly ice-filled canyon incised on the north flank of the volcano and came to rest on the heavily crevassed surface of the piedmont lobe of Drift glacier. Most dome-collapse events resulted in single, monolithologic, massive to reversely graded, medium- to coarse-grained, sandy pyroclastic-flow deposits containing abundant dense dome clasts. These deposits vary in thickness, grain size, and texture depending on distance from the vent and local topography; deposits are finer and better sorted down flow, thinner and finer on hummocks, and thicker and coarser where ponded in channels cut through the glacial ice. The initial vent-clearing explosions emplaced unusual deposits of glacial ice, snow, and rock in a frozen matrix on the north and south flanks of the volcano. Similar deposits were described at Nevado del Ruiz, Columbia and have probably been emplaced at other snow-and-ice-clad volcanoes, but poor preservation makes them difficult to recognize in the geologic record. In a like fashion, most deposits from the 1989-1990 eruption of Redoubt Volcano may be difficult to recognize and interpret in the future because they were emplaced in an environment where glacio-fluvial processes dominate and quickly obscure the primary depositional record. ?? 1994.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Volcanology and Geothermal Research","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"03770273","usgsCitation":"Gardner, C.A., Neal, C., Waitt, R., and Janda, R.J., 1994, Proximal pyroclastic deposits from the 1989-1990 eruption of Redoubt Volcano, Alaska - stratigraphy, distribution, and physical characteristics: Journal of Volcanology and Geothermal Research, v. 62, no. 1-4, p. 213-250.","startPage":"213","endPage":"250","numberOfPages":"38","costCenters":[],"links":[{"id":228665,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"62","issue":"1-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a8fb5e4b0c8380cd7f8fe","contributors":{"authors":[{"text":"Gardner, C. A.","contributorId":75916,"corporation":false,"usgs":true,"family":"Gardner","given":"C.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":377124,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Neal, C.A. 0000-0002-7697-7825","orcid":"https://orcid.org/0000-0002-7697-7825","contributorId":91122,"corporation":false,"usgs":true,"family":"Neal","given":"C.A.","affiliations":[],"preferred":false,"id":377126,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Waitt, R. B.","contributorId":78766,"corporation":false,"usgs":true,"family":"Waitt","given":"R. B.","affiliations":[],"preferred":false,"id":377125,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Janda, R. J. 0000-0002-3251-8088","orcid":"https://orcid.org/0000-0002-3251-8088","contributorId":64693,"corporation":false,"usgs":true,"family":"Janda","given":"R.","email":"","middleInitial":"J.","affiliations":[{"id":157,"text":"Cascades Volcano Observatory","active":false,"usgs":true}],"preferred":true,"id":377123,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70017655,"text":"70017655 - 1994 - Seismological aspects of the 1989-1990 eruptions at redoubt volcano, Alaska: the SSAM perspective","interactions":[],"lastModifiedDate":"2012-03-12T17:19:53","indexId":"70017655","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2499,"text":"Journal of Volcanology and Geothermal Research","active":true,"publicationSubtype":{"id":10}},"title":"Seismological aspects of the 1989-1990 eruptions at redoubt volcano, Alaska: the SSAM perspective","docAbstract":"SSAM is a simple and inexpensive tool for continuous monitoring of average seismic amplitudes within selected frequency bands in near real-time on a PC-based data acquisition system. During the 1989-1990 eruption sequence at Redoubt Volcano, the potential of SSAM to aid in rapid identification of precursory Long-Period (LP) event swarms was realized, and since this time SSAM has been incorporated in routine monitoring efforts of the Alaska Volcano Observatory. In particular, an eruption that occurred on April 6 was successfully forecast primarily on the basis of recognizing the precursory LP activity on SSAM. Of twenty-two significant eruptions that occurred between December 14 and April 21, eleven had precursory swarms longer than one hour in duration that could be detected on SSAM. For individual swarms, the patterns of relative spectral amplitudes are distinct at each station and remain largely stationary through time, thus indicating that one source may have been preferentially and repeatedly activated throughout the swarm. Typically, a single spectral band dominates the signal at each seismic station: for the vigorous one-day swarm that preceded the first eruption on December 14, signals were sharply peaked in the 1.9-2.7 Hz band at the closest station, located 4 km from the vent, but were dominated by 1.3-1.9 Hz energy at three more distant stations located 7.5-22 km from the vent. The tendency for the signals from different swarms recorded at the same station to be peaked in the same frequency band suggests that all of the sources are characterized by a predominant length scale. Signals from the precursory LP swarms became weaker as the eruption sequence progressed, and swarms that occurred in March and April could only be detected at seismographs on the volcanic edifice. Onset times of precursory LP swarms prior to eruptions ranged from a few hours to about one week, but after the initial vent-clearing phase that ended December 19 these intervals tended to become progressively shorter for successive swarms. These trends in the relative onset times and intensities of successive precursory LP swarms are consistent with an overall depressurization of the magmatic system through time. In general, each of the swarms had an emergent onset, but the intensities did not always increase steadily until the eruptions. Instead, as the time of an eruption approached the intensity usually increased more rapidly before peaking and then declining prior to the eruption; for three of the swarms, two distinct peaks in intensity were apparent. The time intervals between final peaks in swarm intensity and ensuing eruptions ranged from about 2 hours to almost 2 days, but the peaks always occurred closer to the eruptions than to the swarm onsets. Both the onset of LP swarm activity and a decline in intensity prior to an eruption may represent critical points in the process of pressurization that drives the flow of fluids and gas in a sealed magmatic system. A notable exception to this pattern is the eruption of March 9 which lacked a detectable precursory LP swarm, but was followed by an unusually long period of strong LP seismicity that may have been stimulated by a depressurization of the magmatic system resulting from dome failure. On both December 14 and January 2, the spectra of early syn-eruptive signals have peaked signatures much like those of the spectra of precursory LP activity from shortly before the eruptions; these similarities may indicate that the source of precursory seismicity continued to be active during at least the early part of each eruption. In syn-eruptive signals from March and April recorded at stations on the volcanic edifice, the dominant spectral energy progressively shifts with time during the eruption to lower frequencies; at least part of the energy in these signals may have been generated by the debris flows associated with dome failures. ?? 1994.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Volcanology and Geothermal Research","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"03770273","usgsCitation":"Stephens, C., Chouet, B., Page, R., Lahr, J., and Power, J., 1994, Seismological aspects of the 1989-1990 eruptions at redoubt volcano, Alaska: the SSAM perspective: Journal of Volcanology and Geothermal Research, v. 62, no. 1-4, p. 153-182.","startPage":"153","endPage":"182","numberOfPages":"30","costCenters":[],"links":[{"id":228941,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"62","issue":"1-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b8bcfe4b08c986b317acd","contributors":{"authors":[{"text":"Stephens, C.D.","contributorId":18752,"corporation":false,"usgs":true,"family":"Stephens","given":"C.D.","email":"","affiliations":[],"preferred":false,"id":377158,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Chouet, B. A.","contributorId":31813,"corporation":false,"usgs":true,"family":"Chouet","given":"B. A.","affiliations":[],"preferred":false,"id":377160,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Page, R.A.","contributorId":40197,"corporation":false,"usgs":true,"family":"Page","given":"R.A.","email":"","affiliations":[],"preferred":false,"id":377162,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Lahr, J.C.","contributorId":34892,"corporation":false,"usgs":true,"family":"Lahr","given":"J.C.","email":"","affiliations":[],"preferred":false,"id":377161,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Power, J.A.","contributorId":20765,"corporation":false,"usgs":true,"family":"Power","given":"J.A.","email":"","affiliations":[],"preferred":false,"id":377159,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70017658,"text":"70017658 - 1994 - An experiment to detect and locate lightning associated with eruptions of Redoubt Volcano","interactions":[],"lastModifiedDate":"2019-04-05T14:37:17","indexId":"70017658","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1994","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2499,"text":"Journal of Volcanology and Geothermal Research","active":true,"publicationSubtype":{"id":10}},"title":"An experiment to detect and locate lightning associated with eruptions of Redoubt Volcano","docAbstract":"A commercially-available lightning-detection system was temporarily deployed near Cook Inlet, Alaska in an attempt to remotely monitor volcanogenic lightning associated with eruptions of Redoubt Volcano. The system became operational on February 14, 1990; lightning was detected in 11 and located in 9 of the 13 subsequent eruptions. The lightning was generated by ash clouds rising from pyroclastic density currents produced by collapse of a lava dome emplaced near Redoubt's summit. Lightning discharge (flash) location was controlled by topography, which channeled the density currents, and by wind direction. In individual eruptions, early flashes tended to have a negative polarity (negative charge is lowered to ground) while late flashes tended to have a positive polarity (positive charge is lowered to ground), perhaps because the charge-separation process caused coarse, rapid-settling particles to be negatively charged and fine, slow-settling particles to be positively charged. Results indicate that lightning detection and location is a useful adjunct to seismic volcano monitoring, particularly when poor weather or darkness prevents visual observation. The simultaneity of seismicity and lightning near a volcano provides the virtual certainty that an ash cloud is present. This information is crucial for aircraft safety and to warn threatened communities of impending tephra falls. The Alaska Volcano Observatory has now deployed a permanent lightning-detection network around Cook Inlet.
","language":"English","publisher":"Elsevier","doi":"10.1016/0377-0273(94)90049-3","issn":"03770273","usgsCitation":"Hoblitt, R., 1994, An experiment to detect and locate lightning associated with eruptions of Redoubt Volcano: Journal of Volcanology and Geothermal Research, v. 62, no. 1-4, p. 499-517, https://doi.org/10.1016/0377-0273(94)90049-3.","productDescription":"19 p.","startPage":"499","endPage":"517","costCenters":[{"id":615,"text":"Volcano Hazards Program","active":true,"usgs":true}],"links":[{"id":229035,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"62","issue":"1-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059ea62e4b0c8380cd4881b","contributors":{"authors":[{"text":"Hoblitt, R.","contributorId":89536,"corporation":false,"usgs":true,"family":"Hoblitt","given":"R.","affiliations":[],"preferred":false,"id":377171,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ]}