Publications
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What is that mysterious booming sound?
The residents of coastal North Carolina are occasionally treated to sequences of booming sounds of unknown origin. The sounds are often energetic enough to rattle windows and doors. A recent sequence occurred in early January 2011 during clear weather with no evidence of local thunder storms. Queries by a local reporter (Colin Hackman of the NBC affiliate WETC in Wilmington, North Carolina, person
Authors
David P. Hill
Magnitude and timing of downstream channel aggradation and degradation in response to a dome-building eruption at Mount Hood, Oregon
A dome-building eruption at Mount Hood, Oregon, starting in A.D. 1781 and lasting until ca. 1793, produced dome-collapse lithic pyroclastic flows that triggered lahars and intermittently fed 108 m3 of coarse volcaniclastic sediment to sediment reservoirs in headwater canyons of the Sandy River. Mobilization of dominantly sandy sediment from these reservoirs by lahars and seasonal floods initiated
Authors
Thomas C. Pierson, Patrick T. Pringle, Kenneth A. Cameron
Volcanic plume height measured by seismic waves based on a mechanical model
In August 2008 an unmonitored, largely unstudied Aleutian volcano, Kasatochi, erupted catastrophically. Here we use seismic data to infer the height of large eruptive columns such as those of Kasatochi based on a combination of existing fluid and solid mechanical models. In so doing, we propose a connection between a common, observable, short-period seismic wave amplitude to the physics of an erup
Authors
Stephanie G. Prejean, Emily E. Brodsky
Shallow conduit system at Kilauea Volcano, Hawaii, revealed by seismic signals associated with degassing bursts
Eruptive activity at the summit of Kilauea Volcano, Hawaii, beginning in March, 2008 and continuing to the present time is characterized by episodic explosive bursts of gas and ash from a vent within Halemaumau Pit Crater. These bursts are accompanied by seismic signals that are well recorded by a broadband network deployed in the summit caldera. We investigate in detail the dimensions and oscilla
Authors
Bernard Chouet, Phillip Dawson
Satellite and ground observations of the June 2009 eruption of Sarychev Peak volcano, Matua Island, Central Kuriles
After 33 years of repose, one of the most active volcanoes of the Kurile island arc—Sarychev Peak on Matua Island in the Central Kuriles—erupted violently on June 11, 2009. The eruption lasted 9 days and stands among the largest of recent historical eruptions in the Kurile Island chain. Satellite monitoring of the eruption, using Moderate Resolution Imaging Spectroradiometer, Meteorological Agency
Authors
A. Rybin, M. Chibisova, P. Webley, T. Steensen, P. Izbekov, Christina A. Neal, V. Realmuto
Eruptive history of South Sister, Oregon Cascades
South Sister is southernmost and highest of the Three Sisters, three geologically dissimilar stratovolcanoes that together form a spectacular 20km reach along the Cascade crest in Oregon. North Sister is a monotonously mafic edifice as old as middle Pleistocene, Middle Sister a basalt-andesite-dacite cone built between 48 and 14ka, and South Sister is a basalt-free edifice that alternated rhyoliti
Authors
J. Fierstein, W. Hildreth, A.T. Calvert
Infrasound from the 2007 fissure eruptions of Kīlauea Volcano, Hawai'i
Varied acoustic signals were recorded at Kīlauea Volcano in mid-2007, coincident with dramatic changes in the volcano's activity. Prior to this time period, Pu'u 'Ō'ō crater produced near-continuous infrasonic tremor and was the primary source of degassing and lava effusion at Kīlauea. Collapse and draining of Pu'u 'Ō'ō crater in mid-June produced impulsive infrasonic signals and fluctuations in
Authors
D. Fee, M. Garces, T. Orr, Michael P. Poland
Brittle and ductile friction and the physics of tectonic tremor
Observations of nonvolcanic tremor provide a unique window into the mechanisms of deformation and failure in the lower crust. At increasing depths, rock deformation gradually transitions from brittle, where earthquakes occur, to ductile, with tremor occurring in the transitional region. The physics of deformation in the transition region remain poorly constrained, limiting our basic understanding
Authors
Eric G. Daub, David R. Shelly, Robert A. Guyer, P.A. Johnson
Positive feedback and momentum growth during debris-flow entrainment of wet bed sediment
Debris flows typically occur when intense rainfall or snowmelt triggers landslides or extensive erosion on steep, debris-mantled slopes. The flows can then grow dramatically in size and speed as they entrain material from their beds and banks, but the mechanism of this growth is unclear. Indeed, momentum conservation implies that entrainment of static material should retard the motion of the flows
Authors
Richard M. Iverson, Mark E. Reid, Matthew Logan, Richard G. Lahusen, Jonathan W. Godt, Julia P. Griswold
Pigeonholing pyroclasts: Insights from the 19 March 2008 explosive eruption of Kīlauea volcano
We think, conventionally, of volcanic explosive eruptions as being triggered in one of two ways: by release and expansion of volatiles dissolved in the ejected magma (magmatic explosions) or by transfer of heat from magma into an external source of water (phreatic or phreatomagmatic explosions). We document here an event where neither magma nor an external water source was involved in explosive ac
Authors
Bruce F. Houghton, Don Swanson, R.J. Carey, J. Rausch, Andrew Sutton
Episodic intrusion, internal differentiation, and hydrothermal alteration of the Miocene Tatoosh intrusive suite south of Mount Rainier, Washington
The Miocene Tatoosh intrusive suite south of Mount Rainier is composed of three broadly granodioritic plutons that are manifestations of ancestral Cascades arc magmatism. Tatoosh intrusive suite plutons have individually diagnostic characteristics, including texture, mineralogy, and geochemistry, and apparently lack internal contacts. New ion-microprobe U-Pb zircon ages indicate crystallization of
Authors
Edward A. du Bray, Charles R. Bacon, David John, Joseph L. Wooden, Frank K. Mazdab
Deep long-period earthquakes beneath Washington and Oregon volcanoes
Deep long-period (DLP) earthquakes are an enigmatic type of seismicity occurring near or beneath volcanoes. They are commonly associated with the presence of magma, and found in some cases to correlate with eruptive activity. To more thoroughly understand and characterize DLP occurrence near volcanoes in Washington and Oregon, we systematically searched the Pacific Northwest Seismic Network (PNSN)
Authors
M.L. Nichols, S. D. Malone, Seth C. Moran, Weston A. Thelen, J.E. Vidale