Publications
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Seismo-acoustic signals associated with degassing explosions recorded at Shishaldin Volcano, Alaska, 2003-2004
In summer 2003, a Chaparral Model 2 microphone was deployed at Shishaldin Volcano, Aleutian Islands, Alaska. The pressure sensor was co-located with a short-period seismometer on the volcano’s north flank at a distance of 6.62 km from the active summit vent. The seismo-acoustic data exhibit a correlation between impulsive acoustic signals (1–2 Pa) and long-period (LP, 1–2 Hz) earthquakes. Since it
Authors
T. Petersen
Lava effusion rate definition and measurement: a review
Measurement of effusion rate is a primary objective for studies that model lava flow and magma system dynamics, as well as for monitoring efforts during on-going eruptions. However, its exact definition remains a source of confusion, and problems occur when comparing volume flux values that are averaged over different time periods or spatial scales, or measured using different approaches. Thus our
Authors
Sonia Calvari, Jonathan Dehn, A. Harris
Precursory seismicity associated with frequent, large ice avalanches on Iliamna Volcano, Alaska, USA
Since 1994, at least six major (volume>106 m3) ice and rock avalanches have occurred on Iliamna volcano, Alaska, USA. Each of the avalanches was preceded by up to 2 hours of seismicity believed to represent the initial stages of failure. Each seismic sequence begins with a series of repeating earthquakes thought to represent slip on an ice-rock interface, or between layers of ice. This stage is fo
Authors
Jacqueline Caplan-Auerbach, C. Huggel
Eruption and deposition of the Fisher Tuff (Alaska)--Evidence for the evolution of pyroclastic flows
Recognition that the Fisher Tuff (Unimak Island, Alaska) was deposited on the leeside of an ∼500–700‐m‐high mountain range (Tugamak Range) more than 10 km away from its source played a major role in defining pyroclastic flows as momentum‐driven currents. We reexamined the Fisher Tuff to evaluate whether deposition from expanded turbulent clouds can better explain its depositional features. We stud
Authors
Alain Burgisser, J.E. Gardner, P. Stelling
Glacier-volcano interactions in the north crater of Mt. Wrangell, Alaska
Glaciological and related observations from 1961 to 2005 at the summit of Mt Wrangell (62.008 N, 144.028W; 4317 m a.s.l.), a massive glacier-covered shield volcano in south-central Alaska, show marked changes that appear to have been initiated by the Great Alaska Earthquake (MW = 9.2) of 27 March 1964. The 4 x 6 km diameter, ice-filled Summit Caldera with several post-caldera craters on its rim, c
Authors
Carl Abston, Roman J. Motyka, Stephen McNutt, Martin Luthi, Martin Truffer
Directed blasts and blast-generated pyroclastic density currents: a comparison of the Bezymianny 1956, Mount St Helens 1980, and Soufrière Hills, Montserrat 1997 eruptions and deposits
We compare eruptive dynamics, effects and deposits of the Bezymianny 1956 (BZ), Mount St Helens 1980 (MSH), and Soufrière Hills volcano, Montserrat 1997 (SHV) eruptions, the key events of which included powerful directed blasts. Each blast subsequently generated a high-energy stratified pyroclastic density current (PDC) with a high speed at onset. The blasts were triggered by rapid unloading of an
Authors
Alexander Belousov, Barry Voight, Marina Belousova
Zircon crystallization and recycling in the magma chamber of the rhyolitic Kos Plateau Tuff (Aegean arc)
In contrast to most large-volume silicic magmas in continental arcs, which are thought to evolve as open systems with significant assimilation of preexisting crust, the Kos Plateau Tuff magma formed dominantly by crystal fractionation of mafic parents. Deposits from this ∼60 km3 pyroclastic eruption (the largest known in the Aegean arc) lack xenocrystic zircons [secondary ion mass spectrometry (SI
Authors
O. Bachman, B. L. A. Charlier, J. B. Lowenstern
South San Francisco Bay, California
The U.S. Geological Survey, in cooperation with the California Coastal Conservancy and the National Oceanic and Atmospheric Administration, mapped the floor of south San Francisco Bay and adjoining land using single-beam sonar and airborne lidar (light detection and ranging). To learn more, visit http://pubs.usgs.gov/sim/2007/2987/.
View eastward. Elevations in mapped area color coded: purple (a
Authors
Peter Dartnell, Helen Gibbons
Surface-source downhole seismic analysis in R
This report discusses a method for interpreting a layered slowness or velocity model from surface-source downhole seismic data originally presented by Boore (2003). I have implemented this method in the statistical computing language R (R Development Core Team, 2007), so that it is freely and easily available to researchers and practitioners that may find it useful. I originally applied an early v
Authors
Eric M. Thompson
EAARL topography – Gateway National Recreation Area, Sandy Hook Unit
This Web site contains Lidar-derived topography (bare earth) maps and GIS files for the Sandy Hook Unit within Gateway National Recreation Area in New Jersey.
These Lidar-derived topography maps were produced as a collaborative effort between the U.S. Geological Survey (USGS) Coastal and Marine Geology Program, FISC St. Petersburg, the National Park Service (NPS) South Florida/Caribbean Network I
Authors
John Brock, C. Wayne Wright, Matt Patterson, Amar Nayegandhi, Judd Patterson
EAARL topography: Gulf Islands National Seashore: Mississippi
This Web site contains 30 lidar-derived bare earth topography maps and GIS files for the Gulf Islands National Seashore-Mississippi.These lidar-derived topography maps were produced as a collaborative effort between the U.S. Geological Survey (USGS) Coastal and Marine Geology Program, FISC St. Petersburg, Florida, the National Park Service (NPS) Gulf Coast Network, Inventory and Monitoring Program
Authors
John Brock, C. Wayne Wright, Amar Nayegandhi, Matt Patterson, Iris Wilson, Laurinda J. Travers
Hawaiian Volcano Observatory 1985 Annual Administrative Report
INTRODUCTORY NOTE
The Hawaiian Volcano Observatory Summaries have been published in the current format since 1956. The Quarterly Summaries (1956 through 1973) and the Annual Summaries (1974 through 1985) were originally published as Administrative Reports. These reports have been compiled and published as U.S. Geological Survey Open-File Reports. The quarterly reports have been combined and pub
Authors
Jennifer S. Nakata