Publications
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Volatile emissions and gas geochemistry of Hot Spring Basin, Yellowstone National Park, USA
We characterize and quantify volatile emissions at Hot Spring Basin (HSB), a large acid-sulfate region that lies just outside the northeastern edge of the 640 ka Yellowstone Caldera. Relative to other thermal areas in Yellowstone, HSB gases are rich in He and H2, and mildly enriched in CH4 and H2S. Gas compositions are consistent with boiling directly off a deep geothermal liquid at depth as it mi
Authors
C. Werner, S. Hurwitz, William C. Evans, J. B. Lowenstern, D. Bergfeld, H. Heasler, C. Jaworowski, A. Hunt
Multiple plagioclase crystal populations identified by crystal size distribution and in situ chemical data: Implications for timescales of magma chamber processes associated with the 1915 eruption of Lassen Peak, CA
Products of the 1915 Lassen Peak eruption reveal evidence for a magma recharge–magma mixing event that may have catalyzed the eruption and from which four compositional members were identified: light dacite, black dacite, andesitic inclusion, and dark andesite. Crystal size distribution, textural, and in situ chemical (major and trace element and Sr isotope) data for plagioclase from these composi
Authors
M.J. Salisbury, W. A. Bohrson, M.A. Clynne, F.C. Ramos, P. Hoskin
4D volcano gravimetry
Time-dependent gravimetric measurements can detect subsurface processes long before magma flow leads to earthquakes or other eruption precursors. The ability of gravity measurements to detect subsurface mass flow is greatly enhanced if gravity measurements are analyzed and modeled with ground-deformation data. Obtaining the maximum information from microgravity studies requires careful evaluation
Authors
Maurizio Battaglia, J. Gottsmann, D. Carbone, J. Fernandez
Evolution of CO2 in Lakes Monoun and Nyos, Cameroon, before and during controlled degassing
Evolution of CO2 in Lakes Monoun and Nyos (Cameroon) before and during controlled degassing is described using results of regular monitoring obtained during the last 21 years. The CO2(aq) profiles soon after the limnic eruptions were estimated for Lakes Monoun and Nyos using the CTD data obtained in October and November 1986, respectively. Based on the CO2(aq)profiles through time, the CO2 content
Authors
M. Kusakabe, T. Ohba, Issa, Y. Yoshida, H. Satake, T. Ohizumi, William C. Evans, G. Tanyileke, G.W. Kling
Oxygen isotope geochemistry of the lassen volcanic center, California: Resolving crustal and mantle contributions to continental Arc magmatism
This study reports oxygen isotope ratios determined by laser fluorination of mineral separates (mainly plagioclase) from basaltic andesitic to rhyolitic composition volcanic rocks erupted from the Lassen Volcanic Center (LVC), northern California. Plagioclase separates from nearly all rocks have δ18O values (6·1–8·4‰) higher than expected for production of the magmas by partial melting of little e
Authors
T.C. Feeley, M.A. Clynne, G.S. Winer, W.C. Grice
Initial fluvial response to the removal of Oregon's Marmot Dam
A temporary, 14‐meter‐high earthen cofferdam standing in place of Marmot Dam was breached on 19 October 2007, allowing the 80‐ kilometer‐long Sandy River to flow freely from Mount Hood, Oreg., to the Columbia River for the first time in nearly 100 years. Marmot Dam is one of the largest dams in the western United States (in terms of height and volume of stored sediment) to have been removed in the
Authors
Jon J. Major, Kurt R. Spicer, Abagail Rhode, J. E. O'Connor, Heather M. Bragg, Dwight Q. Tanner, Chauncey W. Anderson, J. Rose Wallick, Gordon E. Grant
Characteristics, extent and origin of hydrothermal alteration at Mount Rainier Volcano, Cascades Arc, USA: Implications for debris-flow hazards and mineral deposits
Hydrothermal alteration at Mount Rainier waxed and waned over the 500,000-year episodic growth of the edifice. Hydrothermal minerals and their stable-isotope compositions in samples collected from outcrop and as clasts from Holocene debris-flow deposits identify three distinct hypogene argillic/advanced argillic hydrothermal environments: magmatic-hydrothermal, steam-heated, and magmatic steam (fu
Authors
D. A. John, T. W. Sisson, G. N. Breit, R. O. Rye, J.W. Vallance
Pre-1991 sulfur transfer between mafic injections and dacite magma in the Mt. Pinatubo reservoir
Before the 1991–1992 activity, a large andesite lava dome belonging to the penultimate Pinatubo eruptive period (Buag ∼ 500 BP) formed the volcano summit. Buag porphyritic andesite contains abundant amphibole-bearing microgranular enclaves of basaltic–andesite composition. Buag enclaves have lower K2O and incompatible trace element (LREE, U, Th) contents than mafic pulses injected in the Pinatubo
Authors
Muro A. Di, John S. Pallister, B. Villemant, Chris Newhall, M. Semet, M. Martinez, C. Mariet
Volcanic tsunamis and prehistoric cultural transitions in Cook Inlet, Alaska
The 1883 eruption of Augustine Volcano produced a tsunami when a debris avalanche traveled into the waters of Cook Inlet. Older debris avalanches and coeval paleotsunami deposits from sites around Cook Inlet record several older volcanic tsunamis. A debris avalanche into the sea on the west side of Augustine Island ca. 450 years ago produced a wave that affected areas 17 m above high tide on Augus
Authors
J. Beget, Cynthia A. Gardner, K. Davis
A volcano rekindled: The renewed eruption of Mount St. Helens, 2004-2006
Mount St. Helens began a dome-building eruption in September 2004 after nearly two decades of quiescence. Dome growth was initially robust, became more sluggish with time, and ceased completely in late January 2008. The volcano has been quiet again since January 2008.
Professional Paper 1750 describes the first 1 1/2 years of this eruptive activity, chiefly from September 2004 until December 2
Authors
David R. Sherrod, William E. Scott, Peter H. Stauffer
Hydrologic investigations concerning lead mining issues in southeastern Missouri
Good stewardship of our Nation's natural resources demands that the extraction of exploitable, minable ore deposits be conducted in harmony with the protection of the environment, a dilemma faced by many land and water management agencies in the Nation's mining areas. As ore is mined, milled, and sent to the smelter, it leaves footprints where it has been in the form of residual trace metals. Ofte
Authors
Cheryl M. Seeger, Michael J. Kleeschulte, Lopaka Lee, Gary W. Krizanich, Suzanne R. Femmer, John G. Schumacher
2006 volcanic activity in Alaska, Kamchatka, and the Kurile Islands: Summary of events and response of the Alaska Volcano Observatory
The Alaska Volcano Observatory (AVO) responded to eruptions, possible eruptions, and volcanic unrest at or near nine separate volcanic centers in Alaska during 2006. A significant explosive eruption at Augustine Volcano in Cook Inlet marked the first eruption within several hundred kilometers of principal population centers in Alaska since 1992. Glaciated Fourpeaked Mountain, a volcano thought to
Authors
Christina A. Neal, Robert G. McGimsey, James P. Dixon, Alexander Manevich, Alexander Rybin