Publications
Filter Total Items: 7538
Geology of the United States' seafloor: the view from GLORIA Geology of the United States' seafloor: the view from GLORIA
No abstract available.
Authors
James V. Gardner, Michael E. Field, David C. Twichell
Reflected seismic waves and their effect on strong shaking during the 1989 Loma Prieta, California, earthquake Reflected seismic waves and their effect on strong shaking during the 1989 Loma Prieta, California, earthquake
Our data indicate that critical and postcritical reflections from crustal layers and the Moho produced increased shaking at discrete distances along the San Francisco Peninsula during the 1989 Loma Prieta earthquake. These reflections may have produced an increase in amplitude that is as much as 10 times greater than that of the direct arrival. Peak amplitude-distance patterns measured...
Authors
Rufus D. Catchings, W.M. Kohler
Airborne hunt for faults in the Portland-Vancouver area Airborne hunt for faults in the Portland-Vancouver area
Geologic hazards in the Portland-Vancouver area include faults entirely hidden by river sediments, vegetation, and urban development. A recent aerial geophysical survey revealed patterns in the Earth's magnetic field that confirm the existence of a previously suspected fault running through Portland. It also indicated that this fault may pose a significant seismic threat. This discovery...
Authors
Richard J. Blakely, Ray E. Wells, Thomas S. Yelin, Peter H. Stauffer, James W. Hendley
Comparison and contrast of processes of soil formation in the San Timoteo Badlands with chronosequences in California Comparison and contrast of processes of soil formation in the San Timoteo Badlands with chronosequences in California
The degree of soil development associated with geomorphic surfaces in the San Timoteo Badlands area (STB), California allows correlation of the surfaces. Soil development indices, based on field descriptions and laboratory analysis, provide a basis for comparison of these soils to each other and to dated soil chronosequences at Cajon Pass, Merced, and Anza, California. The soils in this...
Authors
Katherine J. Kendrick, Leslie D. McFadden
Preliminary estimates of ground-motion amplification for the Northridge and Hyogo-ken Earthquakes of January 17, 1994 and 1995 Preliminary estimates of ground-motion amplification for the Northridge and Hyogo-ken Earthquakes of January 17, 1994 and 1995
No abstract available.
Authors
Roger D. Borcherdt
Descriptions, photographs, and coordinates for Global Positioning System stations at Aniakchak Crater, Alaska Descriptions, photographs, and coordinates for Global Positioning System stations at Aniakchak Crater, Alaska
No abstract available.
Authors
K.M. Yamashita, E.Y. Iwatsubo, J.J. Dvorak
Direct temperature measurements of deposits, Mount St. Helens, Washington, 1980-1981 Direct temperature measurements of deposits, Mount St. Helens, Washington, 1980-1981
A program of temperature studies of the eruptive products of Mount St. Helens was established May 20, 1980, 2 days after the catastrophic eruption of May 18. Temperature-depth profiles were measured by thermocouple to determine the emplacement temperatures of deposits of the debris avalanche and blast of May 18 and of deposits of the pyroclastic flows of May 18, May 25, June 12, July 22...
Authors
Norman G. Banks, Richard P. Hoblitt
Field test of two single-frequency GPS receivers Field test of two single-frequency GPS receivers
The U.S. Geological Survey's Cascades Volcano Observatory (CVO) has been testing low-cost, low-power Global Positioning System (GPS) receivers for use in the monitoring of restless volcanoes. Field tests of two single-frequency (L1 only) receivers, the Ashtech SCA-12S and the Leica SR261 show that these units can measure positions precisely enough to meet our monitoring needs. For line...
Authors
E.Y. Iwatsubo
Resource assessment of the Bureau of Land Management's Winnemucca District and Surprise Resource Area, Northwest Nevada and Northeast California; geology and its relation to resource genesis Resource assessment of the Bureau of Land Management's Winnemucca District and Surprise Resource Area, Northwest Nevada and Northeast California; geology and its relation to resource genesis
The U.S. Geological Survey (USGS) is a party to joint interagency Memorandum of Understandings (MOUs) with the Bureau of Land Management (BLM) and the U.S. Bureau of Mines (USBM) to coordinate resource assessments and evaluations of BLM administered lands. Resource assessments of BLM Resource Areas, that are conducted by the USGS under these MOUs, assist the BLM in meeting inventory and...
Authors
J. L. Doebrich
Electron microprobe analyses of zeolite minerals from Neogene volcanic rocks in the Breitenbush-Austen Hot Springs area, Oregon Electron microprobe analyses of zeolite minerals from Neogene volcanic rocks in the Breitenbush-Austen Hot Springs area, Oregon
No abstract available.
Authors
R.L. Oscarson, K.E. Bargar
Global volcanic earthquake swarm database 1979-1989 Global volcanic earthquake swarm database 1979-1989
Earthquake swarms are pervasive at volcanoes, but have seldom been studied systematically. Most swarms that are described in the literature are those that occurred in association with eruptions; indeed, earthquake swarms are the most reliable method of forecasting eruptions. For the purpose of this report, a swarm is defined as many earthquakes of the same size occurring in a small...
Authors
J.P. Benoit, S.R. McNutt
Volcanic activity in Alaska: Summary of events and response of the Alaska Volcano Observatory 1993 Volcanic activity in Alaska: Summary of events and response of the Alaska Volcano Observatory 1993
During 1993, the Alaska Volcano Observatory (AVO) responded to episodes of eruptive activity or false alarms at nine volcanic centers in the state of Alaska. Additionally, as part of a formal role in KVERT (the Kamchatkan Volcano Eruption Response Team), AVO staff also responded to eruptions on the Kamchatka Peninsula, details of which are summarized in Miller and Kurianov (1993). In...
Authors
Christina A. Neal, Robert G. McGimsey, Michael P. Doukas