Publications
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Predicting and validating the motion of an ash cloud during the 2006 eruption of Mount Augustine volcano
On 11 January 2006, Mount Augustine volcano in southern Alaska began erupting after 20- year repose. The Anchorage Forecast Office of the National Weather Service (NWS) issued an advisory on 28 January for Kodiak City. On 31 January, Alaska Airlines cancelled all flights to and from Anchorage after multiple advisories from the NWS for Anchorage and the surrounding region. The Alaska Volcano Observ
Authors
Richard L. Collins, Javier Fochesatto, Kenneth Sassen, Peter W. Webley, David E. Atkinson, Kenneson G. Dean, Catherine F. Cahill, Kohei Mizutani
Extensive hydrothermal rock alteration in a low pH, steam-heated environment--Hot Springs Basin, Yellowstone National Park
No abstract available.
Authors
S. Hurwitz, J. B. Lowenstern, D. Bergfeld, C. Werner, H. Heasler, C. Jaworowski
Debris flow hazards mitigation--Mechanics, prediction, and assessment
These proceedings contain papers presented at the Fourth International Conference on Debris-Flow Hazards Mitigation: Mechanics, Prediction, and Assessment held in Chengdu, China, September 10-13, 2007. The papers cover a wide range of topics on debris-flow science and engineering, including the factors triggering debris flows, geomorphic effects, mechanics of debris flows (e.g., rheology, fluv
Incremental assembly and prolonged consolidation of Cordilleran magma chambers--Evidence from the Southern Rocky Mountain volcanic field
Recent inference that Mesozoic Cordilleran plutons grew incrementally during >106 yr intervals, without the presence of voluminous eruptible magma at any stage, minimizes close associations with large ignimbrite calderas. Alternatively, Tertiary ignimbrites in the Rocky Mountains and elsewhere, with volumes of 1–5 × 103 km3, record multistage histories of magma accumulation, fractionation, and so
Authors
Peter W. Lipman
Pāhoehoe flow cooling, discharge, and coverage rates from thermal image chronometry
Theoretically- and empirically-derived cooling rates for active pāhoehoe lava flows show that surface cooling is controlled by conductive heat loss through a crust that is thickening with the square root of time. The model is based on a linear relationship that links log(time) with surface cooling. This predictable cooling behavior can be used assess the age of recently emplaced sheet flows from t
Authors
Jonathan Dehn, Christopher M. Hamilton, A. J. L. Harris, Richard A. Herd, M.R. James, Luigi Lodato, Andrea Steffke
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