Publications
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Failed magmatic eruptions: Late-stage cessation of magma ascent
When a volcano becomes restless, a primary question is whether the unrest will lead to an eruption. Here we recognize four possible outcomes of a magmatic intrusion: "deep intrusion", "shallow intrusion", "sluggish/viscous magmatic eruption", and "rapid, often explosive magmatic eruption". We define "failed eruptions" as instances in which magma reaches but does not pass the "shallow intrusion" st
Authors
S.C. Moran, C. Newhall, D.C. Roman
Early growth of Kohala volcano and formation of long Hawaiian rift zones
Transitional-composition pillow basalts from the toe of the Hilo Ridge, collected from outcrop by submersible, have yielded the oldest ages known from the Island of Hawaii: 1138 ± 34 to 1159 ± 33 ka. Hilo Ridge has long been interpreted as a submarine rift zone of Mauna Kea, but the new ages validate proposals that it is the distal east rift zone of Kohala, the oldest subaerial volcano on the isla
Authors
Peter W. Lipman, Andrew T. Calvert
Experimental study of near-field entrainment of moderately overpressured jets
Particle image velocimetry (PIV) experiments have been conducted to study the velocity flow fields in the developing flow region of high-speed jets. These velocity distributions were examined to determine the entrained mass flow over a range of geometric and flow conditions, including overpressured cases up to an overpressure ratio of 2.83. In the region near the jet exit, all measured flows exhib
Authors
S.A. Solovitz, L.G. Mastin, F. Saffaraval
Triggered creep as a possible mechanism for delayed dynamic triggering of tremor and earthquakes
The passage of radiating seismic waves generates transient stresses in the Earth’s crust that can trigger slip on faults far away from the original earthquake source. The triggered fault slip is detectable in the form of earthquakes and seismic tremor. However, the significance of these triggered events remains controversial, in part because they often occur with some delay, long after the trigger
Authors
David R. Shelly, Zhigang Peng, David P. Hill, Chastity Aiken
Multiplets: Their behavior and utility at dacitic and andesitic volcanic centers
Multiplets, or groups of earthquakes with similar waveforms, are commonly observed at volcanoes, particularly those exhibiting unrest. Using triggered seismic data from the 1980-1986 Mount St. Helens (MSH) eruption, we have constructed a catalog of multiplet occurrence. Our analysis reveals that the occurrence of multiplets is related, at least in part, to the viscosity of the magma. We also const
Authors
W. Thelen, S. Malone, M. West
Volcanic versus anthropogenic carbon dioxide
Which emits more carbon dioxide (CO2): Earth's volcanoes or human activities? Research findings indicate unequivocally that the answer to this frequently asked question is human activities. However, most people, including some Earth scientists working in fields outside volcanology, are surprised by this answer. The climate change debate has revived and reinforced the belief, widespread among clima
Authors
T. Gerlach
Whole-edifice ice volume change A.D. 1970 to 2007/2008 at Mount Rainier, Washington, based on LiDAR surveying
Net changes in thickness and volume of glacial ice and perennial snow at Mount Rainier, Washington State, have been mapped over the entire edifice by differencing between a highresolution LiDAR (light detection and ranging) topographic survey of September-October 2007/2008 and the 10 m lateral resolution U.S. Geological Survey digital elevation model derived from September 1970 aerial photography.
Authors
T. W. Sisson, J.E. Robinson, D.D. Swinney
Migrating swarms of brittle-failure earthquakes in the lower crust beneath Mammoth Mountain, California
Brittle-failure earthquakes in the lower crust, where high pressures and temperatures would typically promote ductile deformation, are relatively rare but occasionally observed beneath active volcanic centers. Where they occur, these earthquakes provide a rare opportunity to observe volcanic processes in the lower crust, such as fluid injection and migration, which may induce brittle faulting unde
Authors
D.R. Shelly, D. P. Hill
Parallelization of GeoClaw code for modeling geophysical flows with adaptive mesh refinement on many-core systems
We parallelized the GeoClaw code on one-level grid using OpenMP in March, 2011 to meet the urgent need of simulating tsunami waves at near-shore from Tohoku 2011 and achieved over 75% of the potential speed-up on an eight core Dell Precision T7500 workstation [1]. After submitting that work to SC11 the International Conference for High Performance Computing, we obtained an unreleased OpenMP versio
Authors
S. Zhang, D.A. Yuen, A. Zhu, S. Song, David L. George
Gas emissions from failed and actual eruptions from Cook Inlet Volcanoes, Alaska, 1989-2006
Cook Inlet volcanoes that experienced an eruption between 1989 and 2006 had mean gas emission rates that were roughly an order of magnitude higher than at volcanoes where unrest stalled. For the six events studied, mean emission rates for eruptions were ~13,000 t/d CO2 and 5200 t/d SO2, but only ~1200 t/d CO2 and 500 t/d SO2 for non-eruptive events (‘failed eruptions’). Statistical analysis sugges
Authors
C.A. Werner, M.P. Doukas, P.J. Kelly
Magma at depth: A retrospective analysis of the 1975 unrest at Mount Baker, Washington, USA
Mount Baker volcano displayed a short interval of seismically-quiescent thermal unrest in 1975, with high emissions of magmatic gas that slowly waned during the following three decades. The area of snow-free ground in the active crater has not returned to pre-unrest levels, and fumarole gas geochemistry shows a decreasing magmatic signature over that same interval. A relative microgravity survey r
Authors
Juliet G. Crider, David Frank, Stephen D. Malone, Michael P. Poland, Cynthia Werner, Jacqueline Caplan-Auerbach
Shallow degassing events as a trigger for very-long-period seismicity at Kīlauea Volcano, Hawai‘i
The first eruptive activity at Kīlauea Volcano’s summit in 25 years began in March 2008 with the opening of a 35-m-wide vent in Halema‘uma‘u crater. The new activity has produced prominent very-long-period (VLP) signals corresponding with two new behaviors: episodic tremor bursts and small explosive events, both of which represent degassing events from the top of the lava column. Previous work has
Authors
Matthew Patrick, David Wilson, David Fee, Tim R. Orr, Donald A. Swanson