Publications
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The perception of volcanic risk in Kona communities from Mauna Loa and Hualālai volcanoes, Hawai'i The perception of volcanic risk in Kona communities from Mauna Loa and Hualālai volcanoes, Hawai'i
Volcanic hazards in Kona (i.e. the western side of the island of Hawai'i) stem primarily from Mauna Loa and Hualālai volcanoes. The former has erupted 39 times since 1832. Lava flows were emplaced in Kona during seven of these eruptions and last impacted Kona in 1950. Hualālai last erupted in ca. 1800. Society's proximity to potential eruptive sources and the potential for relatively...
Authors
Chris E. Gregg, Bruce F. Houghton, David M. Johnston, Douglas Paton, D. A. Swanson
Chemical versus temporal controls on the evolution of tholeiitic and calc-alkaline magmas at two volcanoes in the Alaska-Aleutian arc Chemical versus temporal controls on the evolution of tholeiitic and calc-alkaline magmas at two volcanoes in the Alaska-Aleutian arc
The Alaska-Aleutian island arc is well known for erupting both tholeiitic and calc-alkaline magmas. To investigate the relative roles of chemical and temporal controls in generating these contrasting liquid lines of descent we have undertaken a detailed study of tholeiitic lavas from Akutan volcano in the oceanic A1eutian arc and calc-alkaline products from Aniakchak volcano on the...
Authors
R. George, S. Turner, C. Hawkesworth, C. R. Bacon, C. Nye, P. Stelling, S. Dreher
High-rate real-time GPS network at Parkfield: Utility for detecting fault slip and seismic displacements High-rate real-time GPS network at Parkfield: Utility for detecting fault slip and seismic displacements
A network of 13 continuous GPS stations near Parkfield, California has been converted from 30 second to 1 second sampling with positions of the stations estimated in real-time relative to a master station. Most stations are near the trace of the San Andreas fault, which exhibits creep. The noise spectra of the instantaneous 1 Hz positions show flicker noise at high frequencies and change...
Authors
J. Langbein, Y. Bock
Rear-arc vs. arc-front volcanoes in the Katmai reach of the Alaska Peninsula: A critical appraisal of across-arc compositional variation Rear-arc vs. arc-front volcanoes in the Katmai reach of the Alaska Peninsula: A critical appraisal of across-arc compositional variation
Physical and compositional data and K-Ar ages are reported for 14 rear-arc volcanoes that lic 11-22 km behind the narrowly linear volcanic front defined by the Mount Katmai-to-Devils Desk chain on the Alaska Peninsula. One is a 30-km3 stratocone (Mount Griggs; 51-63% SiO2) active intermittently from 292 ka to Holocene. The others are monogenetic cones, domes, lava flows, plugs, and maars...
Authors
W. Hildreth, J. Fierstein, D. F. Siems, J. R. Budahn, J. Ruiz
2000 volcanic activity in Alaska and Kamchatka: summary of events and response of the Alaska Volcano Observatory 2000 volcanic activity in Alaska and Kamchatka: summary of events and response of the Alaska Volcano Observatory
No abstract available.
Authors
Christina A. Neal, Robert G. McGimsey, Olga Chubarova
Eruptive history and chemical evolution of the precaldera and postcaldera basalt-dacite sequences, Long Valley, California: Implications for magma sources, current seismic unrest, and future volcanism Eruptive history and chemical evolution of the precaldera and postcaldera basalt-dacite sequences, Long Valley, California: Implications for magma sources, current seismic unrest, and future volcanism
The Long Valley Volcanic Field in east-central California straddles the East Sierran frontal fault zone, overlapping the Sierra Nevada and western Basin and Range Provinces. The volcanic field overlies a mature mid-Tertiary erosional surface that truncates a basement composed mainly of Mesozoic plutons and associated roof pendants of Mesozoic metavolcanic and Paleozoic metasedimentary...
Authors
Roy A. Bailey
Volcanological perspectives on Long Valley, Mammoth Mountain, and Mono Craters: Several contiguous but discrete systems Volcanological perspectives on Long Valley, Mammoth Mountain, and Mono Craters: Several contiguous but discrete systems
The volcanic history of the Long Valley region is examined within a framework of six successive (spatially discrete) foci of silicic magmatism, each driven by locally concentrated basaltic intrusion of the deep crust in response to extensional unloading and decompression melting of the upper mantle. A precaldera dacite field (3.5–2.5 Ma) northwest of the later site of Long Valley and the...
Authors
W. Hildreth
Quantifying probabilities of volcanic events: The example of volcanic hazard at Mount Vesuvius Quantifying probabilities of volcanic events: The example of volcanic hazard at Mount Vesuvius
We describe an event tree scheme to quantitatively estimate both long- and short-term volcanic hazard. The procedure is based on a Bayesian approach that produces a probability estimation of any possible event in which we are interested and can make use of all available information including theoretical models, historical and geological data, and monitoring observations. The main steps...
Authors
W. Marzocchi, L. Sandri, P. Gasparini, C. Newhall, Enzo Boschi
Transient volcano deformation sources imaged with interferometric synthetic aperture radar: Application to Seguam Island, Alaska Transient volcano deformation sources imaged with interferometric synthetic aperture radar: Application to Seguam Island, Alaska
Thirty interferometric synthetic aperture radar (InSAR) images, spanning various intervals during 1992–2000, document coeruptive and posteruptive deformation of the 1992–1993 eruption on Seguam Island, Alaska. A procedure that combines standard damped least squares inverse methods and collective surfaces, identifies three dominant amorphous clusters of deformation point sources...
Authors
Timothy Masterlark, Zhong Lu
Debris flows: geologic process and hazard; illustrated by a surge sequence at Jiangjia Ravine, Yunnan, China Debris flows: geologic process and hazard; illustrated by a surge sequence at Jiangjia Ravine, Yunnan, China
Debris flows are slurries of sediment and water that are both an important geologic process and a major hazard. They present large risks to those living in mountainous areas, as well as downstream from volcanoes in the case of the flows known as lahars that may travel 100200 kilometers (62-124 miles). The accompanying video records a series of debris flow surges at Jiangjia Ravine, in...
Authors
Kevin M. Scott, Wang Yuyi
The threat of silent earthquakes The threat of silent earthquakes
Not all earthquakes shake the ground. The so-called silent types are forcing scientists to rethink their understanding of the way quake-prone faults behave. In rare instances, silent earthquakes that occur along the flakes of seaside volcanoes may cascade into monstrous landslides that crash into the sea and trigger towering tsunamis. Silent earthquakes that take place within fault zones...
Authors
Peter Cervelli
Decompression experiments identify kinetic controls on explosive silicic eruptions Decompression experiments identify kinetic controls on explosive silicic eruptions
Eruption intensity is largely controlled by decompression‐induced release of water‐rich gas dissolved in magma. It is not simply the amount of gas that dictates how forcefully magma is propelled upwards during an eruption, but also the rate of degassing, which is partly a function of the supersaturation pressure (ΔPcritical) triggering gas bubble nucleation. High temperature and pressure
Authors
M. T. Mangan, T. W. Sisson, W.B. Hankins