Publications
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Seismicity, gas emission and deformation from 18 July to 25 September 1995 during the initial phreatic phase of the eruption of Soufrière Hills Volcano, Montserrat
On 18 July 1995, after more than three years of irregularly increasing seismicity, phreatic explosions opened a new vent on Soufrière Hills Volcano, about 4 km east of the capital city of Plymouth, Montserrat. By early August 1995, the volcano was monitored by a nine-station seismic network, three telemetered electronic tiltmeters, and daily correlation spectroscopy (COSPEC) flights to measure SO2
Authors
Cynthia A. Gardner, Randall A. White
Paleoenvironments of sedimentary interbeds in the Pliocene and Quaternary Big Lost Trough, eastern Snake River Plain, Idaho
No abstract available.
Authors
Erick A. Bestland, Paul K. Link, Marvin A. Lanphere, Duane E. Champion
Accumulation and subsidence of the Pleistocene basaltic lava flows of the eastern Snake River Plain, Idaho
No abstract available.
Authors
Duane E. Champion, Marvin A. Lanphere, Steven R. Anderson, Mel A. Kuntz
Publications of the Volcano Hazards Program 2001
The Volcano Hazards Program of the U.S. Geological Survey (USGS) is part of the Geologic Hazards Assessments subactivity as funded by Congressional appropriation. Investigations are carried out in the Geology and Hydrology Disciplines of the USGS and with cooperators at the Alaska Division of Geological and Geophysical Surveys, University of Alaska Fairbanks Geophysical Institute, University of Ha
Authors
Manuel Nathenson
Sulfur dioxide emission rates from Kīlauea Volcano, Hawai‘i, an update: 1998-2001
Introduction Sulfur dioxide (SO2) emission rates from Kilauea Volcano were first measured by Stoiber and Malone (1975) and have been measured on a regular basis since 1979 (Greenland and others, 1985; Casadevall and others, 1987; Elias and others, 1998; Sutton and others, 2001). A compilation of SO2 emission-rate and wind-vector data from 1979 through 1997 is available as Open-File Report 98-462 (
Authors
Tamar Elias, A. Jefferson Sutton
Preliminary volcano-hazard assessment for Kanaga Volcano, Alaska
Kanaga Volcano is a steep-sided, symmetrical, cone-shaped, 1307 meter high, andesitic stratovolcano on the north end of Kanaga Island (51°55’ N latitude, 177°10’ W longitude) in the western Aleutian Islands of Alaska. Kanaga Island is an elongated, low-relief (except for the volcano) island, located about 35 kilometers west of the community of Adak on Adak Island and is part of the Andreanof Islan
Authors
Christopher F. Waythomas, Thomas P. Miller, Christopher J. Nye
Steady subsidence of Medicine Lake volcano, northern California, revealed by repeated leveling surveys
Leveling surveys of a 193‐km circuit across Medicine Lake volcano (MLV) in 1954 and 1989 show that the summit area subsided by as much as 302 ± 30 mm (−8.6 ± 0.9 mm/yr) with respect to a datum point near Bartle, California, 40 km to the southwest. This result corrects an error in the earlier analysis of the same data by Dzurisin et al. [1991], who reported the subsidence rate as −11.1 ± 1.2 mm/yr.
Authors
Daniel Dzurisin, Michael P. Poland, Roland Burgmann
Source mechanism of very-long-period signals accompanying dome growth activity at Merapi volcano, Indonesia
Very-long-period (VLP) pulses with period of 6–7s, displaying similar waveforms, were identified in 1998 from broadband seismographs around the summit crater. These pulses accompanied most of multiphase (MP) earthquakes, a type of long-period event locally defined at Merapi Volcano. Source mechanisms for several VLP pulses were examined by applying moment tensor inversion to the waveform data. Sol
Authors
D. Hidayat, B. Chouet, B. Voight, P. Dawson, Antonius Ratdomopurbo
North-central Oregon Cascades; exploring petrologic and tectonic intimacy in a propagating intra-arc rift
No abstract available.
Authors
Richard M. Conrey, Edward M. Taylor, Julie M. Donnelly-Nolan, David R. Sherrod
Morphology, volcanism, and mass wasting in Crater Lake, Oregon
Crater Lake was surveyed nearly to its shoreline by high-resolution multibeam echo sounding in order to define its geologic history and provide an accurate base map for research and monitoring surveys. The bathymetry and acoustic backscatter reveal the character of landforms and lead to a chronology for the concurrent filling of the lake and volcanism within the ca. 7700 calibrated yr B.P. caldera
Authors
C. R. Bacon, J.V. Gardner, L. A. Mayer, M. W. Buktenica, P. Dartnell, D.W. Ramsey, J.E. Robinson
A Holocene paleosecular variation from 14C-dated volcanic rocks in western North America
A paleosecular variation (PSV) curve for western North America is presented on the basis of 94 virtual geomagnetic poles (VGPs) from dated volcanic rocks sampled at 446 sites. Approximately 60% of the paleomagnetic database has been previously published. A curve defined by “spherical smoothed splines” is fitted to the VGPs, ranked by the quality of the age determinations, where the data density is
Authors
Jonathan T. Hagstrum, Duane E. Champion
Ancient and modern subduction zone contributions to the mantle sources of lavas from the Lassen region of California inferred from Lu-Hf isotopic systematics
Hafnium isotopic compositions have been determined on a suite of calc-alkaline and high-alumina-olivine tholeiitic lavas from the Lassen region of California and are used, in conjunction with previously published mineralogical, geochemical, and isotopic data, to constrain their petrogenesis. Positive correlation between εHf values and geochemical indices of the modern subduction component indicate
Authors
L. E. Borg, Janne Blichert-Toft, Michael A. Clynne