Publications
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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
An updated numerical simulation of the ground-water flow system for the Castle Lake debris dam, Mount St. Helens, Washington, and implications for dam stability against heave An updated numerical simulation of the ground-water flow system for the Castle Lake debris dam, Mount St. Helens, Washington, and implications for dam stability against heave
A numerical simulation of the ground-water flow system in the Castle Lake debris dam, calibrated to data from the 1991 and 1992 water years, was used to estimate factors of safety against heave and internal erosion. The Castle Lake debris dam, 5 miles northwest of the summit of Mount St. Helens, impounds 19,000 acre-ft of water that could pose a flood hazard in the event of a lake...
Authors
Evelyn A. Roeloffs
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
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
Convective heat discharge of Wood River group of springs in the vicinity of Crater Lake, Oregon Convective heat discharge of Wood River group of springs in the vicinity of Crater Lake, Oregon
Data sets for spring and stream chemistry are combined to estimate convective heat discharge and discharge anomalous amounts of sodium and chloride for the Wood River group of springs south of Crater Lake. The best estimate of heat discharge is 87 MWt based on chloride inventory; this value is 3-5 times the heat input to Crater Lake itself. Anomalous discharges of sodium and chloride are...
Authors
Manuel Nathenson, Robert H. Mariner, J. Michael Thompson
Disruption of Drift glacier and origin of floods during the 1989-1990 eruptions of Redoubt Volcano, Alaska Disruption of Drift glacier and origin of floods during the 1989-1990 eruptions of Redoubt Volcano, Alaska
Melting of snow and glacier ice during the 1989–1990 eruption of Redoubt Volcano caused winter flooding of the Drift River. Drift glacier was beheaded when 113 to 121 × 106 m3 of perennial snow and ice were mechanically entrained in hot-rock avalanches and pyroclastic flows initiated by the four largest eruptions between 14 December 1989 and 14 March 1990. The disruption of Drift glacier...
Authors
D.C. Trabant, R. B. Waitt, J. J. Major
Late Quaternary normal faulting of the Hat Creek basalt, northern California Late Quaternary normal faulting of the Hat Creek basalt, northern California
The Hat Creek fault is a major, young, north-striking, normal fault along the western boundary of extensional Basin and Range deformation in the Lessen region of northeastern California. Volcanic rocks of Quaternary and late Pliocene age are displaced a total of >500 m down to the west along west-facing, en echelon scarps now retreated to ∼35° slopes. Fresh, young scarps as much as 30 m...
Authors
L.I.P. Muffler, M.A. Clynne, D.E. Champion
Measurements of thermal-water discharge outside Lassen Volcanic National Park, California, 1983-94 Measurements of thermal-water discharge outside Lassen Volcanic National Park, California, 1983-94
No abstract available.
Authors
Michael L. Sorey, Elizabeth M. Colvard, S. E. Ingebritsen
Chemistry of spring and well waters on Kilauea Volcano, Hawaii, and vicinity Chemistry of spring and well waters on Kilauea Volcano, Hawaii, and vicinity
Published and new data for chemical and isotopic samples from wells and springs on Kilauea Volcano and vicinity are presented. These data are used to understand processes that determine the chemistry of dilute meteoric water, mixtures with sea water, and thermal water. Data for well and spring samples of non-thermal water indicate that mixing with sea water and dissolution of rock from...
Authors
Cathy J. Janik, Manuel Nathenson, M. A. Scholl
Volcanic activity and ground deformation hazard analysis for the Hawaii Geothermal Project environmental impact statement Volcanic activity and ground deformation hazard analysis for the Hawaii Geothermal Project environmental impact statement
No abstract available
Authors
James P. Kauahikaua, Richard B. Moore, Paul T. Delaney
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