Publications
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Probabilistic volcanic hazard and risk assessment
[No abstract available]
Authors
W. Marzocchi, A. Neri, C. G. Newhall, P. Papale
Three-dimensional P-wave velocity structure derived from local earthquakes at the Katmai group of volcanoes, Alaska
The three-dimensional P-wave velocity structure beneath the Katmai group of volcanoes is determined by inversion of more than 10,000 rays from over 1000 earthquakes recorded on a local 18 station short-period network between September 1996 and May 2001. The inversion is well constrained from sea level to about 6 km below sea level and encompasses all of the Katmai volcanoes; Martin, Mageik, Triden
Authors
A.D. Jolly, S.C. Moran, S.R. McNutt, D.B. Stone
System for ranking relative threats of U.S. volcanoes
A methodology to systematically rank volcanic threat was developed as the basis for prioritizing volcanoes for long-term hazards evaluations, monitoring, and mitigation activities. A ranking of 169 volcanoes in the United States and the Commonwealth of the Northern Mariana Islands (U.S. volcanoes) is presented based on scores assigned for various hazard and exposure factors. Fifteen factors define
Authors
John W. Ewert
Interferogram formation in the presence of complex and large deformation
Sierra Negra volcano in Isabela island, Galápagos, erupted from October 22 to October 30 in 2005. During the 8 days of eruption, the center of Sierra Negra's caldera subsided about 5.4 meters. Three hours prior to the onset of the eruption, an earthquake (Mw 5.4) occurred, near the caldera. Because of the large and complex phase gradient due to the huge subsidence and the earthquake, it is difficu
Authors
S.-H. Yun, H. Zebker, P. Segall, A. Hooper, Michael P. Poland
Spatial and temporal geochemical trends in the hydrothermal system of Yellowstone National Park: Inferences from river solute fluxes
We present and analyze a chemical dataset that includes the concentrations and fluxes of HCO3−, SO42−, Cl−, and F− in the major rivers draining Yellowstone National Park (YNP) for the 2002–2004 water years (1 October 2001 – 30 September 2004). The total (molar) flux in all rivers decreases in the following order, HCO3− > Cl− > SO42− > F−, but each river is characterized by a distinct chemical comp
Authors
Shaul Hurwitz, Jacob B. Lowenstern, Henry Heasler
ASAR images a diverse set of deformation patterns at Kilauea volcano, Hawai'i
Since 2003, 27 independent look angles have been acquired by ENVISAT’s Advanced Synthetic Aperture Radar (ASAR) instrument over the island of Hawai`i, allowing for the formation of thousands of interferograms showing deformation of the ground surface. On Kīlauea volcano, a transition from minor to broad-scale summit inflation was observed by interferograms that span 2003 to 2006. In addition, rada
Authors
Michael P. Poland
A multiple-approach radiometric age estimate for the Rotoiti and Earthquake Flat eruptions, New Zealand, with implications for the MIS 4/3 boundary
Pyroclastic fall deposits of the paired Rotoiti and Earthquake Flat eruptions from the Taupo Volcanic Zone (New Zealand) combine to form a widespread isochronous horizon over much of northern New Zealand and the southwest Pacific. This horizon is important for correlating climatic and environmental changes during the Last Glacial period, but has been the subject of numerous disparate age estimates
Authors
C. J. N. Wilson, D.A. Rhoades, M. A. Lanphere, A.T. Calvert, Bruce F. Houghton, S.D. Weaver, J. W. Cole
Development of the California Current during the past 12,000 yr based on diatoms and silicoflagellates
Detailed diatom and silicoflagellates records in three cores from the offshore region of southern Oregon to central California reveal the evolution of the northern part of the California Current during the past 12,000 yr. The early Holocene, prior to ∼ 9 ka, was characterized by relatively warm sea surface temperatures (SST), owing to enhanced northerly flow of the subtropical waters comparable to
Authors
John A. Barron, David Bukry
New K-Ar ages for calculating end-of-shield extrusion rates at West Maui volcano, Hawaiian island chain
Thirty-seven new K–Ar ages from West Maui volcano, Hawai‘i, are used to define the waning stages of shield growth and a brief episode of postshield volcanism. All but two samples from shield-stage strata have reversed polarity magnetization, so conceivably the exposed shield is not much older than the Olduvai Normal-Polarity subchron, or about 1.8 Ma. The oldest ages obtained are in the range 1.9–
Authors
David R. Sherrod, T. Murai, Takahiro Tagami
Compositional zoning of the Bishop Tuff
Compositional data for >400 pumice clasts, organized according to eruptive sequence, crystal content, and texture, provide new perspectives on eruption and pre-eruptive evolution of the >600 km3 of zoned rhyolitic magma ejected as the Bishop Tuff during formation of Long Valley caldera. Proportions and compositions of different pumice types are given for each ignimbrite package and for the interca
Authors
W. Hildreth, C. J. N. Wilson
Electrical activity during the 2006 Mount St. Augustine volcanic eruptions
By using a combination of radio frequency time-of-arrival and interferometer measurements, we observed a sequence of lightning and electrical activity during one of Mount St. Augustine's eruptions. The observations indicate that the electrical activity had two modes or phases. First, there was an explosive phase in which the ejecta from the explosion appeared to be highly charged upon exiting the
Authors
Ronald J. Thomas, Paul R. Krehbiel, William Rison, H. E. Edens, G. D. Aulich, S.R. McNutt, Guy Tytgat, E. Clark
Discussion of The mantle plume debate in undergraduate geoscience education: Overview, history, and recommendations
No abstract available.
Authors
Robert I. Tilling