Publications
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Application of near real-time radial semblance to locate the shallow magmatic conduit at Kilauea Volcano, Hawaii Application of near real-time radial semblance to locate the shallow magmatic conduit at Kilauea Volcano, Hawaii
Radial Semblance is applied to broadband seismic network data to provide source locations of Very-Long-Period (VLP) seismic energy in near real time. With an efficient algorithm and adequate network coverage, accurate source locations of VLP energy are derived to quickly locate the shallow magmatic conduit system at Kilauea Volcano, Hawaii. During a restart in magma flow following a...
Authors
P. Dawson, D. Whilldin, B. Chouet
Triggered deformation and seismic activity under Mammoth Mountain in Long Valley caldera by the 3 November 2002 Mw 7.9 Denali fault earthquake Triggered deformation and seismic activity under Mammoth Mountain in Long Valley caldera by the 3 November 2002 Mw 7.9 Denali fault earthquake
The 3 November 2002 Mw 7.9 Denali fault earthquake triggered deformational offsets and microseismicity under Mammoth Mountain (MM) on the rim of Long Valley caldera, California, some 3460 km from the earthquake. Such strain offsets and microseismicity were not recorded at other borehole strain sites along the San Andreas fault system in California. The Long Valley offsets were recorded...
Authors
M.J.S. Johnston, S. G. Prejean, D.P. Hill
1999 Volcanic activity in Alaska and Kamchatka: Summary of events and response of the Alaska Volcano Observatory 1999 Volcanic activity in Alaska and Kamchatka: Summary of events and response of the Alaska Volcano Observatory
The Alaska Volcano Observatory (AVO) monitors 41 historically active volcanoes along the Aleutian Arc. Twenty are seismically monitored and for the rest, the AVO monitoring program relies mainly on daily analysis of satellite images, pilot reports, and observations of local residents and ship's crews. In 1999, AVO responded to eruptive activity or suspect volcanic activity at 7 volcanic...
Authors
Robert G. McGimsey, Christina A. Neal, Olga Girina
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
Renewed unrest at Mount Spurr Volcano, Alaska Renewed unrest at Mount Spurr Volcano, Alaska
The Alaska Volcano Observatory (AVO),a cooperative program of the U.S. Geological Survey, the University of Alaska Fairbanks Geophysical Institute, and the Alaska Division of Geological and Geophysical Surveys, has detected unrest at Mount Spurr volcano, located about 125 km west of Anchorage, Alaska, at the northeast end of the Aleutian volcanic arc. This activity consists of increased...
Authors
John A. Power
The 26 May 1982 breakout flows derived from failure of a volcanic dam at El Chichón, Chiapas, Mexico The 26 May 1982 breakout flows derived from failure of a volcanic dam at El Chichón, Chiapas, Mexico
The eruptions of El Chichón between 28 March and 4 April 1982 produced a variety of pyroclastic deposits. The climactic phase, on 3 April at 07:35 (4 April at 01:35 GMT), destroyed the central andesitic dome and fed pyroclastic surges and flows that dammed nearby drainages, including the Magdalena River. By late April, a lake had formed, 4 km long and 300–400 m wide, containing a volume...
Authors
J.L. Macias, L. Capra, K. M. Scott, J.M. Espindola, A. Garcia-Palomo, J. E. Costa
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
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
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
Complex proximal deposition during the Plinian eruptions of 1912 at Novarupta, Alaska Complex proximal deposition during the Plinian eruptions of 1912 at Novarupta, Alaska
Proximal (
Authors
Bruce F. Houghton, C. J. N. Wilson, J. Fierstein, W. Hildreth
Oxidized sulfur-rich mafic magma at Mount Pinatubo, Philippines Oxidized sulfur-rich mafic magma at Mount Pinatubo, Philippines
Basaltic fragments enclosed in andesitic dome lavas and pyroclastic flows erupted during the early stages of the 1991 eruption of Mount Pinatubo, Philippines, contain amphiboles that crystallized during the injection of mafic magma into a dacitic magma body. The amphiboles contain abundant melt inclusions, which recorded the mixing of andesitic melt in the mafic magma and rhyolitic melt...
Authors
J.C.M. de Hoog, K.H. Hattori, R. Hoblitt
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