Publications
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Increased pressure from rising bubbles as a mechanism for remotely triggered seismicity
Aftershocks of large earthquakes tend to occur close to the main rupture zone, and can be used to constrain its dimensions. But following the 1992 Landers earthquake (magnitude M(w) = 7.3) in southern California, many aftershocks were reported in areas remote from the mainshock. Intriguingly, this remote seismicity occurred in small clusters near active volcanic and geothermal systems. For one of
Authors
A. T. Linde, I. S. Sacks, M.J.S. Johnston, D. P. Hill, R.G. Bilham
Rapid geomorphic change caused by glacial outburst floods and debris flows along Tahoma Creek, Mount Rainier, Washington, USA
As part of a hazards-assessment study, we examined the nature and rate of geomorphic change caused by outburst floods and debris flows along Tahoma Creek. Mount Rainier, since 1967. Archival aerial photographs of the area proved to be a rich source of qualitative geomorphic information. On the basis of limited direct evidence and considerations of stream hydrology, we conclude that nearly all of t
Authors
J. S. Walder, C. L. Driedger
Rare earth element contents and multiple mantle sources of the transform-related Mount Edgecumbe basalts, southeastern Alaska
Pleistocene basalt of the Mount Edgecumbe volcanic field (MEF) is subdivided into a plagioclase type and an olivine type. Olivine basalt crops out farther inboard from the nearby Fairweather transform than plagioclase basalt. Th/La ratios of plagioclase basalt are similar to those of mid-ocean-ridge basalt (MORB), whereas those of olivine basalt are of continental affinity. The olivine basalt has
Authors
J.R. Riehle, J. R. Budahn, M. A. Lanphere, D. A. Brew
Eruptive activity at Mount St Helens, Washington, USA, 1984-1988: a gas geochemistry perspective
The results from two different types of gas measurement, telemetered in situ monitoring of reducing gases on the dome and airborne measurements of sulfur dioxide emission rates in the plume by correlation spectrometry, suggest that the combination of these two methods is particularly effective in detecting periods of enhanced degassing that intermittently punctuate the normal background leakage of
Authors
K.A. McGee, A. J. Sutton
Potassium-argon geochronology of a basalt-andesite-dacite arc system: the Mount Adams volcanic field, Cascade Range of southern Washington
High-precision K-Ar dating and detailed mapping have established an eruptive chronology for a Cascade stratovolcano and its surrounding array of coeval basaltic centers. The time-volume-composition data bear upon several fundamental questions concerning the long-term behavior of arc volcanoes. -from Authors
Authors
W. Hildreth, M. A. Lanphere
Six years of change in Lake Nyos, Cameroon, yield clues to the past and cautions for the future
The catastrophic release of gas from Lake Nyos, Cameroon, in 1986 caused substantial but incomplete mixing of the stratified water column. The post-release evolution of water-column structure has been monitored through April 1992. Changes began immediately after the event as rainfall and inflow brought dilute fluid into the surface layer. Inflow and surface mixing have gradually deepened the chemo
Authors
William C. Evans, L. D. White, M. L. Tuttle, G.W. Kling, G. Tanyileke, R. L. Michel
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 single flow
Authors
T. C. Pierson, R. J. Janda
Chaotic deposition by a giant wave, Molokai, Hawaii
A coral-basalt breccia-conglomerate is exposed >60m above present sea level and nearly 2km inland from the present shoreline on the southwest side of East Molokai Volcano. This deposits was apparently laid down by a giant wave that broke over an outer reef, similar to the present fringing reef, and advanced as a turbulent bore over the back-reef flat, picking up a slurry of carbonate-rich debris a
Authors
J. G. Moore, W.B. Bryan, K. R. Ludwig
Correlation of gold in siliceous sinters with 3He 4He in hot spring waters of Yellowstone National Park
Opaline sinter samples collected at Yellowstone National Park (YNP) were analyzed for gold by neutron activation and for other trace elements by the inductively coupled plasma optical emission spectroscopy (ICP-OES) method. No correlation was found between Au and As, Sb, or total Fe in the sinters, although the sample containing the highest Au also contains the highest Sb. There also was no correl
Authors
R.O. Fournier, B. M. Kennedy, M. Aoki, J. M. Thompson
Dissolved volatile concentrations in an ore-forming magma
Infrared spectroscopic measurements of glass inclusions within quartz phenocrysts from the Plinian fallout of the 22 Ma tuff of Pine Grove show that the trapped silicate melt contained high concentrations of H2O and CO2. Intrusive porphyries from the Pine Grove system are nearly identical in age, composition, and mineralogy to the tephra, and some contain high-grade Mo mineralization. Assuming tha
Authors
J. B. Lowenstern
Uranium-Series Ages of Travertines and Timing of the Last Glaciation in the Northern Yellowstone Area, Wyoming-Montana
Uranium-series age determinations by mass spectrometric methods were done for travertines and associated carbonate veins related to clastic deposits of the last glaciation (Pinedale) in the northern Yellowstone area. Dramatic variations in the hydrologic head are inferred from variations in the elevation of travertine deposition with time and are consistent with the expected hydrologic effects of
Authors
N.C. Sturchio, K. L. Pierce, M.T. Murrell, M. L. Sorey
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 also larg
Authors
Manuel Nathenson, Robert H. Mariner, J. Michael Thompson