Publications
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Short-period volcanic gas precursors to phreatic eruptions: Insights from Poás Volcano, Costa Rica
Volcanic eruptions involving interaction with water are amongst the most violent and unpredictable geologic phenomena on Earth. Phreatic eruptions are exceptionally difficult to forecast by traditional geophysical techniques. Here we report on short-term precursory variations in gas emissions related to phreatic blasts at Poás volcano, Costa Rica, as measured with an in situ multiple gas analyzer
Authors
Maarten de Moor, Alessandro Aiuppa, Javier Pacheco, Geoffroy Avard, Christoph Kern, Marco Liuzzo, Maria Martinez, Gaetano Giudice, Tobias P. Fischer
Mihi Breccia: A stack of lacustrine sediments and subaqueous pyroclastic flows within the Taupo Volcanic Zone, New Zealand
The Taupo Volcanic Zone (TVZ), New Zealand, encompasses a wide variety of arc-related strata, although most of its small-volume (non-caldera-forming) eruptions are poorly-exposed and extensively hydrothermally altered. The Mihi Breccia is a stratigraphic sequence consisting of interbedded rhyolitic pyroclastic flows and lacustrine sediments with eruption ages of 281 ± 18 to at least 239 ± 6 ka (un
Authors
Drew T. Downs
Origin of the pulse-like signature of shallow long-period volcano seismicity
Short-duration, pulse-like long-period (LP) events are a characteristic type of seismicity accompanying eruptive activity at Mount Etna in Italy in 2004 and 2008 and at Turrialba Volcano in Costa Rica and Ubinas Volcano in Peru in 2009. We use the discrete wave number method to compute the free surface response in the near field of a rectangular tensile crack embedded in a homogeneous elastic half
Authors
Bernard A. Chouet, Phillip B. Dawson
Geochemistry, petrologic evolution, and ore deposits of the Miocene Bodie Hills Volcanic Field, California and Nevada
The southern segment of the ancestral Cascades magmatic arc includes numerous volcanic fields; among these, the Bodie Hills volcanic field (BHVF), astride the California-Nevada border north of Mono Lake, is one of the largest (>700 km2) and most well studied. Episodic magmatism in the BHVF spanned about 9 million years between about 15 and 6 Ma; magmatic output was greatest between ca. 15.0 to 12.
Authors
Edward A. du Bray, David John, Brian L. Cousens, Leslie A. Hayden, Peter G. Vikre
Soil data for a vegetation gradient located at Bonanza Creek Long Term Ecological Research Site, interior Alaska
Boreal soils play an important role in the global carbon cycle owing to the large amount of carbon stored within this northern region. To understand how carbon and nitrogen storage varied among different ecosystems, a vegetation gradient was established in the Bonanza Creek Long Term Ecological Research (LTER) site, located in interior Alaska. The ecosystems represented are a black spruce (Picea m
Authors
Kristen L. Manies, Jennifer W. Harden, Christopher C. Fuller, Xiaomei Xu, John P. McGeehin
Operational thermal remote sensing and lava flow monitoring at the Hawaiian Volcano Observatory
Hawaiian volcanoes are highly accessible and well monitored by ground instruments. Nevertheless, observational gaps remain and thermal satellite imagery has proven useful in Hawai‘i for providing synoptic views of activity during intervals between field visits. Here we describe the beginning of a thermal remote sensing programme at the US Geological Survey Hawaiian Volcano Observatory (HVO). Where
Authors
Matthew R. Patrick, James P. Kauahikaua, Tim R. Orr, Ashley G. Davies, Michael S. Ramsey
U.S. Geological Survey Volcano Hazards Program—Assess, forecast, prepare, engage
At least 170 volcanoes in 12 States and 2 territories have erupted in the past 12,000 years and have the potential to erupt again. Consequences of eruptions from U.S. volcanoes can extend far beyond the volcano’s immediate area. Many aspects of our daily life are vulnerable to volcano hazards, including air travel, regional power generation and transmission infrastructure, interstate transportatio
Authors
Wendy K. Stovall, Aleeza M. Wilkins, Charlie Mandeville, Carolyn L. Driedger
Eruptive history of Mammoth Mountain and its mafic periphery, California
This report and accompanying geologic map portray the eruptive history of Mammoth Mountain and a surrounding array of contemporaneous volcanic units that erupted in its near periphery. The moderately alkaline Mammoth eruptive suite, basaltic to rhyodacitic, represents a discrete new magmatic system, less than 250,000 years old, that followed decline of the subalkaline rhyolitic system active benea
Authors
Wes Hildreth, Judy Fierstein
Extraordinary sediment delivery and rapid geomorphic response following the 2008–2009 eruption of Chaitén Volcano, Chile
The 10 day explosive phase of the 2008–2009 eruption of Chaitén volcano, Chile, draped adjacent watersheds with a few cm to >1 m of tephra. Subsequent lava-dome collapses generated pyroclastic flows that delivered additional sediment. During the waning phase of explosive activity, modest rainfall triggered an extraordinary sediment flush which swiftly aggraded multiple channels by many meters. Ten
Authors
Jon J. Major, Daniel Bertin, Thomas C. Pierson, Alvaro Amigo, Andres Iroume, Hector Ulloa, Jonathan M. Castro
A large refined catalog of earthquake relocations and focal mechanisms for the Island of Hawai'i and its seismotectonic implications
We present high-quality focal mechanisms based on a refined earthquake location catalog for the Island of Hawai'i, focusing on Mauna Loa and Kīlauea volcanoes. The relocation catalog is based on first-arrival times and waveform data of both compressional and shear waves for about 180,000 events on and near the Island of Hawai'i between 1986 and 2009 recorded by the seismic stations at the Hawaiian
Authors
Guoqing Lin, Paul G. Okubo
Slab melting and magma formation beneath the southern Cascade arc
The processes that drive magma formation beneath the Cascade arc and other warm-slab subduction zones have been debated because young oceanic crust is predicted to largely dehydrate beneath the forearc during subduction. In addition, geochemical variability along strike in the Cascades has led to contrasting interpretations about the role of volatiles in magma generation. Here, we focus on the Las
Authors
Kristina J. Walowski, Paul J. Wallace, Michael A. Clynne, D.J. Rasmussen, D. Weis
Potential carbon emissions dominated by carbon dioxide from thawed permafrost soils
Increasing temperatures in northern high latitudes are causing permafrost to thaw, making large amounts of previously frozen organic matter vulnerable to microbial decomposition. Permafrost thaw also creates a fragmented landscape of drier and wetter soil conditions that determine the amount and form (carbon dioxide (CO2), or methane (CH4)) of carbon (C) released to the atmosphere. The rate and fo
Authors
Christina Schädel, Martin K.-F. Bader, Edward A.G. Schuur, Christina Biasi, Rosvel Bracho, Petr Čapek, Sarah De Baets, Kateřina Diáková, Jessica Ernakovich, Cristian Estop-Aragones, David E. Graham, Iain P. Hartley, Colleen M. Iversen, Evan S. Kane, Christian Knoblauch, Massimo Lupascu, Pertti J. Martikainen, Susan M. Natali, Richard J. Norby, Jonathan A. O'Donnell, Taniya Roy Chowdhury, Hana Šantrůčková, Gaius Shaver, Victoria L. Sloan, Claire C. Treat, Merritt R. Turetsky, Mark P. Waldrop, Kimberly P. Wickland