Publications
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Long Valley Caldera 2003 through 2014: Overview of low level unrest in the past decade
Long Valley Caldera is located in California along the eastern escarpment of the Sierra Nevada Range. The caldera formed about 760,000 years ago as the eruption of 600 km3 of rhyolite magma (Bishop Tuff) resulted in collapse of the partially evacuated magma chamber. Resurgent doming in the central part of the caldera occurred shortly afterwards, and the most recent eruptions inside the caldera occ
Authors
Stuart K. Wilkinson, David P. Hill, John O. Langbein, Michael Lisowski, Margaret T. Mangan
Attenuation and scattering tomography of the deep plumbing system of Mount St. Helens
We present a combined 3-D P wave attenuation, 2-D S coda attenuation, and 3-D S coda scattering tomography model of fluid pathways, feeding systems, and sediments below Mount St. Helens (MSH) volcano between depths of 0 and 18 km. High-scattering and high-attenuation shallow anomalies are indicative of magma and fluid-rich zones within and below the volcanic edifice down to 6 km depth, where a hig
Authors
Luca De Siena, Christine Thomas, Greg P. Waite, Seth C. Moran, Stefan Klemme
Reducing risk from lahar hazards: Concepts, case studies, and roles for scientists
Lahars are rapid flows of mud-rock slurries that can occur without warning and catastrophically impact areas more than 100 km downstream of source volcanoes. Strategies to mitigate the potential for damage or loss from lahars fall into four basic categories: (1) avoidance of lahar hazards through land-use planning; (2) modification of lahar hazards through engineered protection structures; (3) lah
Authors
Thomas C. Pierson, Nathan J. Wood, Carolyn L. Driedger
Identifying hazards associated with lava deltas
Lava deltas, formed where lava enters the ocean and builds a shelf of new land extending from the coastline, represent a significant local hazard, especially on populated ocean island volcanoes. Such structures are unstable and prone to collapse—events that are often accompanied by small explosions that can deposit boulders and cobbles hundreds of meters inland. Explosions that coincide with colla
Authors
Michael P. Poland, Tim R. Orr
Database for the geologic map of upper Eocene to Holocene volcanic and related rocks in the Cascade Range, Washington
This geospatial database for a geologic map of the Cascades Range in Washington state is one of a series of maps that shows Cascade Range geology by fitting published and unpublished mapping into a province-wide scheme of lithostratigraphic units. Geologic maps of the Eocene to Holocene Cascade Range in California and Oregon complete the series, providing a comprehensive geologic map of the entire
Authors
Andrew D. Barron, David W. Ramsey, James G. Smith
Dynamics of the Yellowstone hydrothermal system
The Yellowstone Plateau Volcanic Field is characterized by extensive seismicity, episodes of uplift and subsidence, and a hydrothermal system that comprises more than 10,000 thermal features, including geysers, fumaroles, mud pots, thermal springs, and hydrothermal explosion craters. The diverse chemical and isotopic compositions of waters and gases derive from mantle, crustal, and meteoric source
Authors
Shaul Hurwitz, Jacob B. Lowenstern
Straddling the tholeiitic/calc-alkaline transition: The effects of modest amounts of water on magmatic differentiation at Newberry Volcano, Oregon
Melting experiments have been performed at 1 bar (anhydrous) and 1- and 2-kbar H2O-saturated conditions to study the effect of water on the differentiation of a basaltic andesite. The starting material was a mafic pumice from the compositionally zoned tuff deposited during the ~75 ka caldera-forming eruption of Newberry Volcano, a rear-arc volcanic center in the central Oregon Cascades. Pumices in
Authors
Ben E. Mandler, Julie M. Donnelly-Nolan, Timothy L. Grove
Chemical complexity and source of the White River Ash, Alaska and Yukon
The White River Ash, a prominent stratigraphic marker bed in Alaska (USA) and Yukon (Canada), consists of multiple compositional units belonging to two geochemical groups. The compositional units are characterized using multiple criteria, with combined glass and ilmenite compositions being the best discriminators. Two compositional units compose the northern group (WRA-Na and WRA-Nb), and two unit
Authors
S.J. Preece, Robert G. McGimsey, J.A. Westgate, N.J.G. Pearce, W.K. Hartmann, W.T. Perkins
Correlations of turbidity to suspended-sediment concentration in the Toutle River Basin, near Mount St. Helens, Washington, 2010-11
Researchers at the U.S. Geological Survey, Cascades Volcano Observatory, investigated alternative methods for the traditional sample-based sediment record procedure in determining suspended-sediment concentration (SSC) and discharge. One such sediment-surrogate technique was developed using turbidity and discharge to estimate SSC for two gaging stations in the Toutle River Basin near Mount St. Hel
Authors
Mark A. Uhrich, Jasna Kolasinac, Pamela L. Booth, Robert L. Fountain, Kurt R. Spicer, Adam R. Mosbrucker
Earthquakes: Hydrogeochemical precursors
Earthquake prediction is a long-sought goal. Changes in groundwater chemistry before earthquakes in Iceland highlight a potential hydrogeochemical precursor, but such signals must be evaluated in the context of long-term, multiparametric data sets.
Authors
Steven E. Ingebritsen, Michael Manga
Provisional maps of thermal areas in Yellowstone National Park, based on satellite thermal infrared imaging and field observations
Maps that define the current distribution of geothermally heated ground are useful toward setting a baseline for thermal activity to better detect and understand future anomalous hydrothermal and (or) volcanic activity. Monitoring changes in the dynamic thermal areas also supports decisions regarding the development of Yellowstone National Park infrastructure, preservation and protection of park r
Authors
R. Greg Vaughan, Henry Heasler, Cheryl Jaworowski, Jacob B. Lowenstern, Laszlo P. Keszthelyi
Understanding heat and groundwater flow through continental flood basalt provinces: insights gained from alternative models of permeability/depth relationships for the Columbia Plateau, USA
Heat-flow mapping of the western USA has identified an apparent low-heat-flow anomaly coincident with the Columbia Plateau Regional Aquifer System, a thick sequence of basalt aquifers within the Columbia River Basalt Group (CRBG). A heat and mass transport model (SUTRA) was used to evaluate the potential impact of groundwater flow on heat flow along two different regional groundwater flow paths. L
Authors
Erick R. Burns, Colin F. Williams, Steven E. Ingebritsen, Clifford I. Voss, Frank A. Spane, Jacob DeAngelo