Publications
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Shear wave velocity variation across the Taupo Volcanic Zone, New Zealand, from receiver function inversion
The Taupo Volcanic Zone (TVZ), New Zealand is a region characterized by very high magma eruption rates and extremely high heat flow, which is manifest in high-temperature geothermal waters. The shear wave velocity structure across the region is inferred using non-linear inversion of receiver functions, which were derived from teleseismic earthquake data. Results from the non-linear inversion, and
Authors
S. Bannister, C.J. Bryan, H.M. Bibby
Geochemical constraints on possible subduction components in lavas of Mayon and Taal Volcanoes, Southern Luzon, Philippines
Mayon is the most active volcano along the east margin of southern Luzon, Philippines. Petrographic and major element data indicate that Mayon has produced a basaltic to andesitic lava series by fractional crystallization and magma mixing. Trace element data indicate that the parental basalts came from a heterogeneous mantle source. The unmodified composition of the mantle wedge is similar to that
Authors
P.R. Castillo, C. G. Newhall
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 in the proc
Authors
W. Marzocchi, L. Sandri, P. Gasparini, C. Newhall, Enzo Boschi
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 brief pause in
Authors
P. Dawson, D. Whilldin, B. Chouet
Earthquake triggering at Alaskan volcanoes following the 3 November 2002 Denali fault earthquake
The 3 November 2002 Mw 7.9 Denali fault earthquake provided an excellent opportunity to investigate triggered earthquakes at Alaskan volcanoes. The Alaska Volcano Observatory operates short-period seismic networks on 24 historically active volcanoes in Alaska, 247-2159 km distant from the mainshock epicenter. We searched for evidence of triggered seismicity by examining the unfiltered waveforms fo
Authors
S.C. Moran, J.A. Power, S.D. Stihler, J.J. Sanchez, J. Caplan-Auerbach
Migration and rearing histories of chinook salmon (Oncorhynchus tshawytscha) determined by ion microprobe Sr isotope and Sr/Ca transects of otoliths
Strontium isotope and Sr/Ca ratios measured in situ by ion microprobe along radial transects of otoliths of juvenile chinook salmon (Oncorhynchus tshawytscha) vary between watersheds with contrasting geology. Otoliths from ocean-type chinook from Skagit River estuary, Washington, had prehatch regions with 87Sr/86Sr ratios of ~0.709, suggesting a maternally inherited marine signature, extensive fre
Authors
C. R. Bacon, P.K. Weber, K.A. Larsen, R. Reisenbichler, J.A. Fitzpatrick, J. L. Wooden
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 on borehole
Authors
M.J.S. Johnston, S. G. Prejean, D. P. Hill
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 Yunnan Prov
Authors
Kevin M. Scott, Wang Yuyi
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
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. Predictions genera
Authors
Timothy Masterlark, Zhong Lu
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 of 26 × 1
Authors
J.L. Macias, L. Capra, K. M. Scott, J.M. Espindola, A. Garcia-Palomo, J. E. Costa
Hawaiian submarine manganese-iron oxide crusts - A dating tool?
Black manganese-iron oxide crusts form on most exposed rock on the ocean floor. Such crusts are well developed on the steep lava slopes of the Hawaiian Ridge and have been sampled during dredging and submersible dives. The crusts also occur on fragments detached from bedrock by mass wasting, on submerged coral reefs, and on poorly lithified sedimentary rocks. The thickness of the crusts was measur
Authors
J. G. Moore, D. A. Clague