Publications
Filter Total Items: 3049
Volcanic mixed avalanches: A distinct eruption-triggered mass-flow process at snow-clad volcanoes Volcanic mixed avalanches: A distinct eruption-triggered mass-flow process at snow-clad volcanoes
A generally unrecognized type of pyroclastic deposit was produced by rapid avalanches of intimately mixed snow and hot pyroclastic debris during eruptions at Mount St. Helens, Nevado del Ruiz, and Redoubt Volcano between 1982 and 1989. These "mixed avalanches" traveled as far as 14 km at velocities up to ∼27 m/s, involved as much as 107 m3 of rock and ice, and left unmelted deposits of...
Authors
T.C. Pierson, R. J. Janda
Precursory swarms of long-period events at Redoubt Volcano (1989-1990), Alaska: Their origin and use as a forecasting tool Precursory swarms of long-period events at Redoubt Volcano (1989-1990), Alaska: Their origin and use as a forecasting tool
During the eruption of Redoubt Volcano from December 1989 through April 1990, the Alaska Volcano Observatory issued advance warnings of several tephra eruptions based on changes in seismic activity related to the occurrence of precursory swarms of long-period (LP) seismic events (dominant period of about 0.5 s). The initial eruption on December 14 occurred after 23 years of quiescence...
Authors
B. A. Chouet, R.A. Page, C.D. Stephens, J.C. Lahr, J.A. Power
Measurements of heat and mass flow from thermal areas in Lassen Volcanic National Park, California, 1984-93 Measurements of heat and mass flow from thermal areas in Lassen Volcanic National Park, California, 1984-93
Rates of heat loss from eight steam-heated thermal areas and one conductively heated thermal area in Lassen Volcanic National Park have been determined from measurements made during the period 1984-93. Total heat discharge at the steam-heated areas is assumed proportional to the rate of steam upflow from underlying reservoirs. The dominant mode of heat loss differs among the areas...
Authors
Michael L. Sorey, Elizabeth M. Colvard
GPS measurements on the island of Hawaii in 1992 GPS measurements on the island of Hawaii in 1992
No abstract available.
Authors
Asta Miklius, E.Y. Iwatsubo, R.P. Denlinger, A.T. Okamura, M. K. Sako, K.M. Yamashita
Preparing for the next eruption in the Cascades Preparing for the next eruption in the Cascades
No abstract available.
Authors
J.W. Ewert, B.M. Myers, S.R. Brantley
Analysis of deep seismic reflection and other data from the southern Washington Cascades Analysis of deep seismic reflection and other data from the southern Washington Cascades
No abstract available.
Authors
W. D. Stanley, S. Y. Johnson, V. F. Nuccio
Campground talk and slide show on volcanoes for Chiricahua National Monument Campground talk and slide show on volcanoes for Chiricahua National Monument
The slides and the accompanying script presented here are based on a campground presentation at Chiricahua National Monument in 1994. Examples of eruptions at active volcanoes are used to help the audience visualize events that took place in the National Monument 27 million years ago. This presentation stresses the following themes: 1) The National Monument lies on the flank of an...
Authors
J.S. Pallister, E. A. Du Bray
Major-element, trace-element, and volatile concentrations in silicate melt inclusions from the tuff of Pine Grove, Wah Wah Mountains, Utah Major-element, trace-element, and volatile concentrations in silicate melt inclusions from the tuff of Pine Grove, Wah Wah Mountains, Utah
No abstract available.
Authors
Jacob B. Lowenstern, Charles R. Bacon, L. C. Calk, R.L. Hervig, R.D. Aines
A compilation of sulfur dioxide and carbon dioxide emission-rate data from Mount St. Helens during 1980-88 A compilation of sulfur dioxide and carbon dioxide emission-rate data from Mount St. Helens during 1980-88
Airborne monitoring of Mount St. Helens by the USGS began inMay 1980 for sulfur dioxide emissions and in July 1980 forcarbon dioxide emissions. A correlation spectrometer, orCOSPEC, was used to measure sulfur dioxide in Mount St.Helens' plume. The upward-looking COSPEC was mounted in afixed-wing aircraft and flown below and at right angles to theplume. Typically, three to six traverses...
Authors
Kenneth A. McGee, Thomas J. Casadevall
Abstracts of the eighth international conference on Geochronology, cosmochronology, and isotope geology Abstracts of the eighth international conference on Geochronology, cosmochronology, and isotope geology
No abstract available.
Authors
Marvin A. Lanphere, G. Brent Dalrymple, Brent D. Turrin
The 1989-1990 eruption of Redoubt Volcano, Alaska: impacts on aircraft operations The 1989-1990 eruption of Redoubt Volcano, Alaska: impacts on aircraft operations
The December 1989–June 1990 eruption of Redoubt Volcano affected commercial and military air operations in the vicinity of Anchorage, Alaska. These effects were due to the direct impact of volcanic ash on jet aircraft, as well as to the rerouting and cancellations of flight operations owing to eruptive activity. Between December and February, five commercial jetliners were damaged from...
Authors
T. J. Casadevall
Hornblende-melt trace-element partitioning measured by ion microprobe Hornblende-melt trace-element partitioning measured by ion microprobe
Trace-element abundances were measured in situ by ion microprobe in five samples of hornblende and melt ranging from basaltic andesite to high-silica rhyolite. Except for one sample, for which quench overgrowth or disequilibrium is suspected, the abundance ratios show systematic inter-element and inter-sample variations, and probably approach true partition coefficients. Apparent...
Authors
T. W. Sisson