William E Scott
In retirement I am working on completing a geologic map of Mount Hood volcano, Oregon.
Science and Products
Filter Total Items: 65
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 a stan
Authors
Stephen P. Horton, Robert D. Norris, Seth C. Moran
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
, 0.095
p
Authors
Marie Edmonds, Kenneth A. McGee, Michael P. Doukas
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 and a seco
Authors
Michael A. Clynne, Andrew T. Calvert, Edward W. Wolfe, Russell C. Evarts, Robert J. Fleck, Marvin A. Lanphere
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 extension,
Authors
Michael Lisowski, Daniel Dzurisin, Roger P. Denlinger, Eugene Y. Iwatsubo
Absolute and relative locations of earthquakes at Mount St. Helens, Washington, using continuous data: Implications for magmatic processes
This study uses a combination of absolute and relative locations from earthquake multiplets to investigate the
seismicity associated with the eruptive sequence at Mount St.
Helens between September 23, 2004, and November 20, 2004.
Multiplets, a prominent feature of seismicity during this time
period, occurred as volcano-tectonic, hybrid, and low-frequency earthquakes spanning a large range of
Authors
Weston A. Thelen, Robert S. Crosson, Kenneth C. Creager
Emission rates of CO2, SO2, and H2S, scrubbing, and preeruption excess volatiles at Mount St. Helens, 2004-2005
Airborne surveillance of gas emissions began at Mount
St. Helens on September 27, 2004. Reconnaissance measurements--SO2
column abundances and CO2
, SO2
, and H2
S
concentrations--showed neither a gas plume downwind of
the volcano nor gas sources within the crater. Subsequent
measurements taken during the period of unrest before the
eruption began on October 1 and for several days after Octo
Authors
Terrence M. Gerlach, Kenneth A. McGee, Michael P. Doukas
Near-real-time information products for Mount St. Helens -- tracking the ongoing eruption
The rapid onset of energetic seismicity on September
23, 2004, at Mount St. Helens caused seismologists at the
Pacific Northwest Seismic Network and the Cascades Volcano Observatory to quickly improve and develop techniques
that summarized and displayed seismic parameters for use by
scientists and the general public. Such techniques included
webicorders (Web-based helicorder-like displays), g
Authors
Anthony I. Qamar, Stephen Malone, Seth C. Moran, William P. Steele, Weston A. Thelen
Pre- and post-eruptive investigations of gas and water samples from Mount St. Helens, Washington, 2002 to 2005
Samples of gas and water from thermal springs in
Loowit and Step canyons and creeks that drain the crater at
Mount St. Helens have been collected since October 2004
to monitor the flux of dissolved magmatic volatiles in the
hydrologic system. The changing composition of the waters
highlights a trend that began as early as 1994 and includes
decreasing SO4
and Cl concentrations and large incr
Authors
D. Bergfeld, William C. Evans, Kenneth A. McGee, Kurt R. Spicer
Seismicity associated with renewed dome building at Mount St. Helens, 2004-2005
The reawakening of Mount St. Helens after 17 years and 11 months of slumber was heralded by a swarm of shallow
(depth 2 earthquakes were
occurring at a rate of ~1 per minute. A gradual transition from
volcano-tectonic to hybrid and low-frequency events occurred
along with this intensification, a characteristic of many precursory swarms at Mount St. Helens before dome-building
eruptions in the
Authors
Seth C. Morgan, Stephen D. Malone, Anthony I. Qamar, Weston A. Thelen, Amy K. Wright, Jacqueline Caplan-Auerbach
Hazard information management during the autumn 2004 reawakening of Mount St. Helens volcano, Washington
The 2004 reawakening of Mount St. Helens quickly
caught the attention of government agencies as well as the
international news media and the public. Immediate concerns
focused on a repeat of the catastrophic landslide and blast
event of May 18, 1980, which remains a vivid memory for
many individuals. Within several days of the onset of accelerating seismicity, media inquiries increased expone
Authors
Carolyn L. Driedger, Christina A. Neal, Tom H. Knappenberger, Deborah H. Needham, Robert B. Harper, William P. Steele
Managing public and media response to a reawakening volcano: lessons from the 2004 eruptive activity of Mount St. Helens
Volcanic eruptions and other infrequent, large-scale
natural disturbances pose challenges and opportunities for
public-land managers. In the days and weeks preceding an
eruption, there can be considerable uncertainty surrounding
the magnitude and areal extent of eruptive effects. At the same
time, public and media interest in viewing developing events
is high and concern for public safety on
Authors
Peter M. Frenzen, Michael T. Matarrese
Overview of the 2004 to 2006, and continuing, eruption of Mount St. Helens, Washington
Rapid onset of unrest at Mount St. Helens on September 23, 2004, initiated an uninterrupted lava-dome-building eruption that continues to the time of writing this overview (spring 2006) for a volume of papers focused on this eruption. About three weeks of intense seismic unrest and localized surface uplift, punctuated by four brief explosions, constituted a ventclearing phase, during which there w
Authors
William E. Scott, David R. Sherrod, Cynthia A. Gardner
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.
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Filter Total Items: 65
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 a stanAuthorsStephen P. Horton, Robert D. Norris, Seth C. MoranChlorine 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 , 0.095 pAuthorsMarie Edmonds, Kenneth A. McGee, Michael P. DoukasThe 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 and a secoAuthorsMichael A. Clynne, Andrew T. Calvert, Edward W. Wolfe, Russell C. Evarts, Robert J. Fleck, Marvin A. LanphereAnalysis 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 extension,AuthorsMichael Lisowski, Daniel Dzurisin, Roger P. Denlinger, Eugene Y. IwatsuboAbsolute and relative locations of earthquakes at Mount St. Helens, Washington, using continuous data: Implications for magmatic processes
This study uses a combination of absolute and relative locations from earthquake multiplets to investigate the seismicity associated with the eruptive sequence at Mount St. Helens between September 23, 2004, and November 20, 2004. Multiplets, a prominent feature of seismicity during this time period, occurred as volcano-tectonic, hybrid, and low-frequency earthquakes spanning a large range ofAuthorsWeston A. Thelen, Robert S. Crosson, Kenneth C. CreagerEmission rates of CO2, SO2, and H2S, scrubbing, and preeruption excess volatiles at Mount St. Helens, 2004-2005
Airborne surveillance of gas emissions began at Mount St. Helens on September 27, 2004. Reconnaissance measurements--SO2 column abundances and CO2 , SO2 , and H2 S concentrations--showed neither a gas plume downwind of the volcano nor gas sources within the crater. Subsequent measurements taken during the period of unrest before the eruption began on October 1 and for several days after OctoAuthorsTerrence M. Gerlach, Kenneth A. McGee, Michael P. DoukasNear-real-time information products for Mount St. Helens -- tracking the ongoing eruption
The rapid onset of energetic seismicity on September 23, 2004, at Mount St. Helens caused seismologists at the Pacific Northwest Seismic Network and the Cascades Volcano Observatory to quickly improve and develop techniques that summarized and displayed seismic parameters for use by scientists and the general public. Such techniques included webicorders (Web-based helicorder-like displays), gAuthorsAnthony I. Qamar, Stephen Malone, Seth C. Moran, William P. Steele, Weston A. ThelenPre- and post-eruptive investigations of gas and water samples from Mount St. Helens, Washington, 2002 to 2005
Samples of gas and water from thermal springs in Loowit and Step canyons and creeks that drain the crater at Mount St. Helens have been collected since October 2004 to monitor the flux of dissolved magmatic volatiles in the hydrologic system. The changing composition of the waters highlights a trend that began as early as 1994 and includes decreasing SO4 and Cl concentrations and large incrAuthorsD. Bergfeld, William C. Evans, Kenneth A. McGee, Kurt R. SpicerSeismicity associated with renewed dome building at Mount St. Helens, 2004-2005
The reawakening of Mount St. Helens after 17 years and 11 months of slumber was heralded by a swarm of shallow (depth 2 earthquakes were occurring at a rate of ~1 per minute. A gradual transition from volcano-tectonic to hybrid and low-frequency events occurred along with this intensification, a characteristic of many precursory swarms at Mount St. Helens before dome-building eruptions in theAuthorsSeth C. Morgan, Stephen D. Malone, Anthony I. Qamar, Weston A. Thelen, Amy K. Wright, Jacqueline Caplan-AuerbachHazard information management during the autumn 2004 reawakening of Mount St. Helens volcano, Washington
The 2004 reawakening of Mount St. Helens quickly caught the attention of government agencies as well as the international news media and the public. Immediate concerns focused on a repeat of the catastrophic landslide and blast event of May 18, 1980, which remains a vivid memory for many individuals. Within several days of the onset of accelerating seismicity, media inquiries increased exponeAuthorsCarolyn L. Driedger, Christina A. Neal, Tom H. Knappenberger, Deborah H. Needham, Robert B. Harper, William P. SteeleManaging public and media response to a reawakening volcano: lessons from the 2004 eruptive activity of Mount St. Helens
Volcanic eruptions and other infrequent, large-scale natural disturbances pose challenges and opportunities for public-land managers. In the days and weeks preceding an eruption, there can be considerable uncertainty surrounding the magnitude and areal extent of eruptive effects. At the same time, public and media interest in viewing developing events is high and concern for public safety onAuthorsPeter M. Frenzen, Michael T. MatarreseOverview of the 2004 to 2006, and continuing, eruption of Mount St. Helens, Washington
Rapid onset of unrest at Mount St. Helens on September 23, 2004, initiated an uninterrupted lava-dome-building eruption that continues to the time of writing this overview (spring 2006) for a volume of papers focused on this eruption. About three weeks of intense seismic unrest and localized surface uplift, punctuated by four brief explosions, constituted a ventclearing phase, during which there wAuthorsWilliam E. Scott, David R. Sherrod, Cynthia A. GardnerNon-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.