Publications
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Postglacial eruptive history, geochemistry, and recent seismicity of Aniakchak volcano, Alaska Peninsula
Aniakchak is a Pleistocene to Holocene composite volcano of the Alaska–Aleutian arc that suffered at least one caldera-forming eruption in postglacial time and last erupted in 1931. The oldest recognized postglacial eruption, Aniakchak I, produced andesite ignimbrite ca. 9,500–7,500 14C yr B.P. Subsequently, a vent northeast of the summit issued dacite–rhyodacite magma ca. 7,000 14C yr B.P. mainly
Authors
Charles R. Bacon, Christina A. Neal, Thomas P. Miller, Robert G. McGimsey, Christopher J. Nye
Digital data for preliminary geologic map of the Mount Hood 30- by 60-minute quadrangle, northern Cascade Range, Oregon
The Mount Hood 30- by 60-minute quadrangle covers the axis and east flank of the Cascade Range in northern Oregon. Its namesake, Mount Hood volcano, dominates the view in the northwest quarter of the quadrangle, but the entire area is underlain by Oligocene and younger volcanic and volcaniclastic rocks of the Cascade Range. Since the time of the Columbia River Basalt Group about 15 million years (
Authors
Lina Ma, David R. Sherrod, William E. Scott
Characteristics of Hawaiian volcanoes
Founded in 1912 at the edge of the caldera of Kīlauea Volcano, HVO was the vision of Thomas A. Jaggar, Jr., a geologist from the Massachusetts Institute of Technology, whose studies of natural disasters around the world had convinced him that systematic, continuous observations of seismic and volcanic activity were needed to better understand—and potentially predict—earthquakes and volcanic erupti
Significance of a near-source tephra-stratigraphic sequence to the eruptive history of Hayes Volcano, south-central Alaska
Bluffs along the Hayes River valley, 31 km northeast and 40 km downstream from Hayes Volcano, reveal volcanic deposits that shed new light on its eruptive history. Three thick (>10 cm) and five thin (<10 cm) tephra-fall deposits are dacitic in whole rock composition and contain high proportions of amphibole to pyroxene and minor biotite and broadly correlate to Hayes tephra set H defined by earlie
Authors
Kristi L. Wallace, Michelle L. Coombs, Leslie A. Hayden, Christopher F. Waythomas
A sight "fearfully grand": eruptions of Lassen Peak, California, 1914 to 1917
On May 22, 1915, a large explosive eruption at the summit of Lassen Peak, California, the southernmost active volcano in the Cascade Range, devastated nearby areas and rained volcanic ash as far away as 280 miles to the east. This explosion was the most powerful in a series of eruptions during 1914–17 that were the last to occur in the Cascade Range before the 1980 eruption of Mount St. Helens, Wa
Authors
Michael A. Clynne, Robert L. Christiansen, Peter H. Stauffer, James W. Hendley, Heather A. Bleick
The California Volcano Observatory: Monitoring the state's restless volcanoes
Volcanic eruptions happen in the State of California about as frequently as the largest earthquakes on the San Andreas Fault Zone. At least 10 eruptions have taken place in California in the past 1,000 years—most recently at Lassen Peak in Lassen Volcanic National Park (1914 to 1917) in the northern part of the State—and future volcanic eruptions are inevitable. The U.S. Geological Survey Californ
Authors
Wendy K. Stovall, Mae Marcaida, Margaret T. Mangan
Discussion and Review of “Seismology of the Oso-Steelhead landslide” by Hibert, Stark, and Ekstrom
In this study, Hibert et al. use the seismic waves generated by the disastrous 22 March 2014 landslide near Oso, Washington to investigate the dynamics of the event by combining long-period source inversions and short period analysis. Overall the paper is concise and well written and takes an innovative approach by integrating both high- and low-frequency seismic data together in the interpretatio
Authors
Kate E. Allstadt
Debris flow from 2012 failure of moraine-dammed lake, Three Fingered Jack volcano, Mount Jefferson Wilderness, Oregon
In the late spring or early summer of 2012, a flood emanated from a small moraine-dammed lake on the northeast flank of Three Fingered Jack in the Mount Jefferson Wilderness. Channel erosion or slope collapse breached the natural dam of the lake, leading to a sudden lowering of lake level by 2.8 m and discharge of 12,700 cubic meters (m3) of water. The resulting debris flow formed a bouldery depos
Authors
David R. Sherrod, Barton B. Wills
Gravity changes and deformation at Kīlauea Volcano, Hawaii, associated with summit eruptive activity, 2009-2012
Analysis of microgravity and surface displacement data collected at the summit of Kīlauea Volcano, Hawaii (USA), between December 2009 and November 2012 suggests a net mass accumulation at ~1.5 km depth beneath the northeast margin of Halema‘uma‘u Crater, within Kīlauea Caldera. Although residual gravity increases and decreases are accompanied by periods of uplift and subsidence of the surface, re
Authors
Marco Bagnardi, Michael P. Poland, Daniele Carbone, Scott Baker, Maurizio Battaglia, Falk Amelung
Localized rejuvenation of a crystal mush recorded in zircon temporal and compositional variation at the Lassen Volcanic Center, northern California
Zircon ages and trace element compositions from recent silicic eruptions in the Lassen Volcanic Center (LVC) allow for an evaluation of the timing and conditions of rejuvenation (reheating and mobilization of crystals) within the LVC magmatic system. The LVC is the southernmost active Cascade volcano and, prior to the 1980 eruption of Mount St. Helens, was the site of the only eruption in the Casc
Authors
Erik W. Klemetti, Michael A. Clynne
Magma-ice-sediment interactions and the origin of lava/hyaloclastite sequences in the Síða formation, South Iceland
Products of subglacial volcanism can illuminate reconstructions of paleo-environmental conditions on both local and regional scales. Competing interpretations of Pleistocene conditions in south Iceland have been proposed based on an extensive sequence of repeating lava-and-hyaloclastite deposits in the Síða district. We propose here a new eruptive model and refine the glacial environment during er
Authors
Tenley J. Banik, Paul J. Wallace, Ármann Höskuldsson, Calvin F. Miller, Charles R. Bacon, David J. Furbish
238U-230Th dating of chevkinite in high-silica rhyolites from La Primavera and Yellowstone calderas
Application of 238U-230Th disequilibrium dating of accessory minerals with contrasting stabilities and compositions can provide a unique perspective on magmatic evolution by placing the thermochemical evolution of magma within the framework of absolute time. Chevkinite, a Th-rich accessory mineral that occurs in peralkaline and metaluminous rhyolites, may be particularly useful as a chronometer of
Authors
Jorge A. Vazquez, Noel O. Velasco, Axel K. Schmitt, Heather A. Bleick, Mark E. Stelten