Publications
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Effects of major storms on Pacific Islands Effects of major storms on Pacific Islands
Tropical storms of various kinds are as much a depositional event as an erosional event. Much attention is given to the destructive aspects of major storms because of the loss of life and property, but little is known about their beneficial effects to coastal accretion. While we can usually measure and map the instantaneous effects of a tropical storm, we can only speculate about the...
Authors
Bruce Richmond
New developments in estimating site response effects on ground motion New developments in estimating site response effects on ground motion
No abstract available.
Authors
Roger D. Borcherdt
Explosive tephra emissions of Mount St. Helens, 1989-1991: the violent escape of magmatic gas following storms? Explosive tephra emissions of Mount St. Helens, 1989-1991: the violent escape of magmatic gas following storms?
From 24 August 1989 until 18 June 1991, Mount St. Helens produced at least 28 shallow, explosion-like seismic events with signatures similar to those produced by gas explosions on the dome during the mid 1980s. At least six were accompanied by violent emission of non-juvenile tephra, ejection of blocks of rock nearly 1 km from the vent, and avalanching of debris off the north side of the...
Authors
L.G. Mastin
An experiment to detect and locate lightning associated with eruptions of Redoubt Volcano An experiment to detect and locate lightning associated with eruptions of Redoubt Volcano
A commercially-available lightning-detection system was temporarily deployed near Cook Inlet, Alaska in an attempt to remotely monitor volcanogenic lightning associated with eruptions of Redoubt Volcano. The system became operational on February 14, 1990; lightning was detected in 11 and located in 9 of the 13 subsequent eruptions. The lightning was generated by ash clouds rising from...
Authors
R. Hoblitt
Stream-channel changes in response to volcanic detritus under natural and augmented discharge, South Coldwater Creek, Washington Stream-channel changes in response to volcanic detritus under natural and augmented discharge, South Coldwater Creek, Washington
No abstract available.
Authors
D. F. Meyer
Dissolved volatile concentrations in an ore-forming magma 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...
Authors
J. B. Lowenstern
Origin of phenocrysts and compositional diversity in pre-Mazama rhyodacite lavas, Crater Lake, Oregon Origin of phenocrysts and compositional diversity in pre-Mazama rhyodacite lavas, Crater Lake, Oregon
Phenocrysts in porphyritic volcanic rocks may originate in a variety of ways in addition to nucleation and growth in the matrix in which they are found. Porphyritic rhyodacite lavas that underlie the eastern half of Mount Mazama, the High Cascade andesite/dacite volcano that contains Crater Lake caldera, contain evidence that bears on the general problem of phenocryst origin. Phenocrysts...
Authors
S. Nakada, C. R. Bacon, A.E. Gartner
Russian volcanic eruption disrupts north pacific air traffic: Alaska Volcano Observatory fact sheet Russian volcanic eruption disrupts north pacific air traffic: Alaska Volcano Observatory fact sheet
No abstract available.
Authors
Thomas P. Miller, Vladimir Yu. Kirianov, H. Lee Kelley
Giant Hawaiian landslides Giant Hawaiian landslides
Sixty-eight landslides more than 20 km long are present along a 2200 km segment of the Hawaiian Ridge from near Midway to Hawaii. Some of the landslides exceed 200 km in length and 5000 km3 in volume, ranking them among the largest on Earth. Most of these giant landslides were discovered during a mapping program of the U.S. Hawaiian Exclusive Economic zone from 1986 to 1991 utilizing the...
Authors
J.G. Moore, W. R. Normark, R. T. Holcomb
Rare earth element contents and multiple mantle sources of the transform-related Mount Edgecumbe basalts, southeastern Alaska 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...
Authors
J.R. Riehle, J. R. Budahn, M. A. Lanphere, D. A. Brew
Large-scale deformation related to the collision of the Aleutian Arc with Kamchatka Large-scale deformation related to the collision of the Aleutian Arc with Kamchatka
The far western Aleutian Island Arc is actively colliding with Kamchatka. Westward motion of the Aleutian Arc is brought about by the tangential relative motion of the Pacific plate transferred to major, right-lateral shear zones north and south of the arc. Early geologic mapping of Cape Kamchatka (a promontory of Kamchatka along strike with the Aleutian Arc) revealed many similarities...
Authors
Eric L. Geist, David W. Scholl