William E Scott
In retirement I am working on completing a geologic map of Mount Hood volcano, Oregon.
Science and Products
Filter Total Items: 70
Identification and evolution of the juvenile component in 2004-2005 Mount St. Helens ash Identification and evolution of the juvenile component in 2004-2005 Mount St. Helens ash
Petrologic studies of volcanic ash are commonly used to identify juvenile volcanic material and observe changes in the composition and style of volcanic eruptions. During the 2004-5 eruption of Mount St. Helens, recognition of the juvenile component in ash produced by early phreatic explosions was complicated by the presence of a substantial proportion of 1980-86 lava-dome fragments and
Authors
Michael C. Rowe, Carl R. Thornber, Adam J. R. Kent
Instrumentation in remote and dangerous settings; examples using data from GPS “spider” deployments during the 2004-2005 eruption of Mount St. Helens, Washington Instrumentation in remote and dangerous settings; examples using data from GPS “spider” deployments during the 2004-2005 eruption of Mount St. Helens, Washington
Self-contained, single-frequency GPS instruments fitted on lightweight stations suitable for helicopter-sling payloads became a critical part of volcano monitoring during the September 2004 unrest and subsequent eruption of Mount St. Helens. Known as “spiders” because of their spindly frames, the stations were slung into the crater 29 times from September 2004 to December 2005 when...
Authors
Richard G. LaHusen, Kelly J. Swinford, Matthew Logan, Michael Lisowski
The Pleistocene eruptive history of Mount St. Helens, Washington, from 300,000 to 12,800 years before present The Pleistocene eruptive history of Mount St. Helens, Washington, from 300,000 to 12,800 years before present
We report the results of recent geologic mapping and radiometric dating that add considerable detail to our understanding of the eruptive history of Mount St. Helens before its latest, or Spirit Lake, stage. New data and reevaluation of earlier work indicate at least two eruptive periods during the earliest, or Ape Canyon, stage, possibly separated by a long hiatus: one about 300-250 ka...
Authors
Michael A. Clynne, Andrew T. Calvert, Edward W. Wolfe, Russell C. Evarts, Robert J. Fleck, Marvin A. Lanphere
Chlorine degassing during the lava dome-building eruption of Mount St. Helens, 2004-2005 Chlorine degassing during the lava dome-building eruption of Mount St. Helens, 2004-2005
Remote measurements of volcanic gases from the Mount St. Helens lava dome were carried out using OpenPath Fourier-Transform Infrared spectroscopy on August 31, 2005. Measurements were performed at a site ~1 km from the lava dome, which was used as a source of IR radiation. On average, during the period of measurement, the volcanic gas contained 99 mol percent H2 O, 0.78 percent CO2 , 0...
Authors
Marie Edmonds, Kenneth A. McGee, Michael P. Doukas
Broadband characteristics of earthquakes recorded during a dome-building eruption at Mount St. Helens, Washington, between October 2004 and May 2005 Broadband characteristics of earthquakes recorded during a dome-building eruption at Mount St. Helens, Washington, between October 2004 and May 2005
From October 2004 to May 2005, the Center for Earthquake Research and Information of the University of Memphis operated two to six broadband seismometers within 5 to 20 km of Mount St. Helens to help monitor recent seismic and volcanic activity. Approximately 57,000 earthquakes identified during the 7-month deployment had a normal magnitude distribution with a mean magnitude of 1.78 and...
Authors
Stephen P. Horton, Robert D. Norris, Seth C. Moran
Analysis of GPS-measured deformation associated with the 2004-2006 dome-building eruption of Mount St. Helens, Washington Analysis of GPS-measured deformation associated with the 2004-2006 dome-building eruption of Mount St. Helens, Washington
Detecting far-field deformation at Mount St. Helens since the crater-forming landslide and blast in 1980 has been difficult despite frequent volcanic activity and improved monitoring techniques. Between 1982 and 1991, the systematic extension of line lengths in a regional GPS trilateration network is consistent with recharge of a deep magma chamber during that interval. The rate of...
Authors
Michael Lisowski, Daniel Dzurisin, Roger P. Denlinger, Eugene Y. Iwatsubo
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
Filter Total Items: 70
Identification and evolution of the juvenile component in 2004-2005 Mount St. Helens ash Identification and evolution of the juvenile component in 2004-2005 Mount St. Helens ash
Petrologic studies of volcanic ash are commonly used to identify juvenile volcanic material and observe changes in the composition and style of volcanic eruptions. During the 2004-5 eruption of Mount St. Helens, recognition of the juvenile component in ash produced by early phreatic explosions was complicated by the presence of a substantial proportion of 1980-86 lava-dome fragments and
Authors
Michael C. Rowe, Carl R. Thornber, Adam J. R. Kent
Instrumentation in remote and dangerous settings; examples using data from GPS “spider” deployments during the 2004-2005 eruption of Mount St. Helens, Washington Instrumentation in remote and dangerous settings; examples using data from GPS “spider” deployments during the 2004-2005 eruption of Mount St. Helens, Washington
Self-contained, single-frequency GPS instruments fitted on lightweight stations suitable for helicopter-sling payloads became a critical part of volcano monitoring during the September 2004 unrest and subsequent eruption of Mount St. Helens. Known as “spiders” because of their spindly frames, the stations were slung into the crater 29 times from September 2004 to December 2005 when...
Authors
Richard G. LaHusen, Kelly J. Swinford, Matthew Logan, Michael Lisowski
The Pleistocene eruptive history of Mount St. Helens, Washington, from 300,000 to 12,800 years before present The Pleistocene eruptive history of Mount St. Helens, Washington, from 300,000 to 12,800 years before present
We report the results of recent geologic mapping and radiometric dating that add considerable detail to our understanding of the eruptive history of Mount St. Helens before its latest, or Spirit Lake, stage. New data and reevaluation of earlier work indicate at least two eruptive periods during the earliest, or Ape Canyon, stage, possibly separated by a long hiatus: one about 300-250 ka...
Authors
Michael A. Clynne, Andrew T. Calvert, Edward W. Wolfe, Russell C. Evarts, Robert J. Fleck, Marvin A. Lanphere
Chlorine degassing during the lava dome-building eruption of Mount St. Helens, 2004-2005 Chlorine degassing during the lava dome-building eruption of Mount St. Helens, 2004-2005
Remote measurements of volcanic gases from the Mount St. Helens lava dome were carried out using OpenPath Fourier-Transform Infrared spectroscopy on August 31, 2005. Measurements were performed at a site ~1 km from the lava dome, which was used as a source of IR radiation. On average, during the period of measurement, the volcanic gas contained 99 mol percent H2 O, 0.78 percent CO2 , 0...
Authors
Marie Edmonds, Kenneth A. McGee, Michael P. Doukas
Broadband characteristics of earthquakes recorded during a dome-building eruption at Mount St. Helens, Washington, between October 2004 and May 2005 Broadband characteristics of earthquakes recorded during a dome-building eruption at Mount St. Helens, Washington, between October 2004 and May 2005
From October 2004 to May 2005, the Center for Earthquake Research and Information of the University of Memphis operated two to six broadband seismometers within 5 to 20 km of Mount St. Helens to help monitor recent seismic and volcanic activity. Approximately 57,000 earthquakes identified during the 7-month deployment had a normal magnitude distribution with a mean magnitude of 1.78 and...
Authors
Stephen P. Horton, Robert D. Norris, Seth C. Moran
Analysis of GPS-measured deformation associated with the 2004-2006 dome-building eruption of Mount St. Helens, Washington Analysis of GPS-measured deformation associated with the 2004-2006 dome-building eruption of Mount St. Helens, Washington
Detecting far-field deformation at Mount St. Helens since the crater-forming landslide and blast in 1980 has been difficult despite frequent volcanic activity and improved monitoring techniques. Between 1982 and 1991, the systematic extension of line lengths in a regional GPS trilateration network is consistent with recharge of a deep magma chamber during that interval. The rate of...
Authors
Michael Lisowski, Daniel Dzurisin, Roger P. Denlinger, Eugene Y. Iwatsubo
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.