Publications
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Eruption dynamics at Mount St. Helens imaged from broadband seismic waveforms: Interaction of the shallow magmatic and hydrothermal systems Eruption dynamics at Mount St. Helens imaged from broadband seismic waveforms: Interaction of the shallow magmatic and hydrothermal systems
The current eruption at Mount St. Helens is characterized by dome building and shallow, repetitive, long-period (LP) earthquakes. Waveform cross-correlation reveals remarkable similarity for a majority of the earthquakes over periods of several weeks. Stacked spectra of these events display multiple peaks between 0.5 and 2 Hz that are common to most stations. Lower-amplitude very-long...
Authors
G.P. Waite, B. A. Chouet, P.B. Dawson
Dynamic stresses, Coulomb failure, and remote triggering Dynamic stresses, Coulomb failure, and remote triggering
Dynamic stresses associated with crustal surface waves with 15-30-sec periods and peak amplitudes 1 MPa are capable of triggering seismicity at sites remote from the generating mainshock under appropriate conditions. Coulomb failure models based on a frictional strength threshold offer one explanation for instances of rapid-onset triggered seismicity that develop during the surface-wave...
Authors
David P. Hill
The dams come down: Unchaining U.S. Rivers The dams come down: Unchaining U.S. Rivers
No abstract available.
Authors
J. O'Connor, Jon J. Major, G. Grant
InSAR observations of deformation associated with new episodes of volcanism at Kilauea Volcano, Hawai'i, 2007 InSAR observations of deformation associated with new episodes of volcanism at Kilauea Volcano, Hawai'i, 2007
In June 2007, the Pu'u 'Ō'ō-Kūpaianaha eruption of Kīlauea Volcano was interrupted when magma intruded the east rift zone (ERZ), resulting in a small extrusion of lava near Makaopuhi Crater. Deformation associated with the activity was exceptionally well-documented by ASAR interferometry, which indicates deflation of the summit and uplift and extension of the ERZ. Models of co-intrusion
Authors
Michael P. Poland
Initial fluvial response to the removal of Oregon's Marmot Dam Initial fluvial response to the removal of Oregon's Marmot Dam
A temporary, 14‐meter‐high earthen cofferdam standing in place of Marmot Dam was breached on 19 October 2007, allowing the 80‐ kilometer‐long Sandy River to flow freely from Mount Hood, Oreg., to the Columbia River for the first time in nearly 100 years. Marmot Dam is one of the largest dams in the western United States (in terms of height and volume of stored sediment) to have been...
Authors
Jon J. Major, Kurt R. Spicer, Abagail Rhode, J. E. O’Connor, Heather M. Bragg, Dwight Q. Tanner, Chauncey W. Anderson, J. Rose Wallick, Gordon E. Grant
Volcanic tsunamis and prehistoric cultural transitions in Cook Inlet, Alaska Volcanic tsunamis and prehistoric cultural transitions in Cook Inlet, Alaska
The 1883 eruption of Augustine Volcano produced a tsunami when a debris avalanche traveled into the waters of Cook Inlet. Older debris avalanches and coeval paleotsunami deposits from sites around Cook Inlet record several older volcanic tsunamis. A debris avalanche into the sea on the west side of Augustine Island ca. 450 years ago produced a wave that affected areas 17 m above high...
Authors
J. Beget, Cynthia A. Gardner, K. Davis
2006 volcanic activity in Alaska, Kamchatka, and the Kurile Islands: Summary of events and response of the Alaska Volcano Observatory 2006 volcanic activity in Alaska, Kamchatka, and the Kurile Islands: Summary of events and response of the Alaska Volcano Observatory
The Alaska Volcano Observatory (AVO) responded to eruptions, possible eruptions, and volcanic unrest at or near nine separate volcanic centers in Alaska during 2006. A significant explosive eruption at Augustine Volcano in Cook Inlet marked the first eruption within several hundred kilometers of principal population centers in Alaska since 1992. Glaciated Fourpeaked Mountain, a volcano...
Authors
Christina A. Neal, Robert G. McGimsey, James P. Dixon, Alexander Manevich, Alexander Rybin
Eruptive and noneruptive calderas, northeastern San Juan Mountains, Colorado: Where did the ignimbrites come from? Eruptive and noneruptive calderas, northeastern San Juan Mountains, Colorado: Where did the ignimbrites come from?
The northeastern San Juan Mountains, the least studied portion of this well-known segment of the Southern Rocky Mountains Volcanic Field are the site of several newly identified and reinterpreted ignimbrite calderas. These calderas document some unique eruptive features not described before from large volcanic systems elsewhere, as based on recent mapping, petrologic data, and a large...
Authors
Peter W. Lipman, William C. McIntosh
Evolution of CO2 in Lakes Monoun and Nyos, Cameroon, before and during controlled degassing Evolution of CO2 in Lakes Monoun and Nyos, Cameroon, before and during controlled degassing
Evolution of CO2 in Lakes Monoun and Nyos (Cameroon) before and during controlled degassing is described using results of regular monitoring obtained during the last 21 years. The CO2(aq) profiles soon after the limnic eruptions were estimated for Lakes Monoun and Nyos using the CTD data obtained in October and November 1986, respectively. Based on the CO2(aq)profiles through time, the...
Authors
M. Kusakabe, T. Ohba, Issa, Y. Yoshida, H. Satake, T. Ohizumi, William C. Evans, G. Tanyileke, G.W. Kling
Using amphibole phenocrysts to track vapor transfer during magma crystallization and transport: An example from Mount St. Helens, Washington Using amphibole phenocrysts to track vapor transfer during magma crystallization and transport: An example from Mount St. Helens, Washington
In order to evaluate and further constrain models for volatile movement and vapor enrichment of magma stored at shallow levels, amphibole phenocrysts from 2004–2005 Mount St. Helens dacite were analyzed for major and selected trace elements (Li, Cu, Zn, Mn, and REE) and Li isotopes. Several recent studies have examined fluid-mobile trace element abundances in phencryst phases and melt...
Authors
M.C. Rowe, A.J.R. Kent, C.R. Thornber
Deformation of the Augustine Volcano, Alaska, 1992-2005, measured by ERS and ENVISAT SAR interferometry Deformation of the Augustine Volcano, Alaska, 1992-2005, measured by ERS and ENVISAT SAR interferometry
The Augustine Volcano is a conical-shaped, active stratovolcano located on an island of the same name in Cook Inlet, about 290 km southwest of Anchorage, Alaska. Augustine has experienced seven significant explosive eruptions - in 1812, 1883, 1908, 1935, 1963, 1976, 1986, and in January 2006. To measure the ground surface deformation of the Augustine Volcano before the 2006 eruption, we...
Authors
Chang-Wook Lee, Zhong Lu, Oh-Ig Kwoun, Joong-Sun Won
Geologic map of Mount St. Helens, Washington prior to the 1980 eruption Geologic map of Mount St. Helens, Washington prior to the 1980 eruption
It is rare that a geologic map exists for a volcano prior to such a catastrophic modification as that produced by the eruption of Mount St. Helens in 1980. As such, this map provides an important historical record of the volcano prior to that eruption. The map has not been reviewed or checked for conformity to USGS editorial standards or stratigraphic nomenclature, and it has not been...
Authors
Clifford A. Hopson