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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 1993, AVO ma
Authors
Christina A. Neal, Robert G. McGimsey, Michael P. Doukas

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 lengths up
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

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 evaluation
Authors
J. L. Doebrich

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 volume. Swarms
Authors
J.P. Benoit, S.R. McNutt

The Topography of Asteroid Ida: A Comparison between Photogrammetric and Shape­Form-Shading Image Analysis

We derived high resolution Digital Terrain Models from stereo images of the asteroid Ida that were obtained by the Galileo spacecraft during the flyby in August 1993 and compared these results with terrain models derived from two-dimensional photoclinometry. The comparison shows that there are striking discrepancies between the results from the two models depending on the spatial scale length of s
Authors
Bernd Giese, Juergen Oberst, Randolph L. Kirk, W. Zeitler

Seismology, geology, and geotechnical issues

The Hyogoken-Nanbu (Kobe) earthquake of January 17, 1995 (5:46:52 JST) occurred in an area of complex faulting located near Awaji Island and the Hanshin area of Japan (34.607 N, 135.043 E, depth 14.3 km; Japan Meteorological Agency, JMA). The area which is near the urban centers of Kobe City and Osaka is located about 250 km from the Nankai trough, which forms the boundary between the Philippine S
Authors
Roger D. Borcherdt, Thomas L. Holzer

Overview of landslide problems, research, and mitigation, Cincinnati, Ohio, area

Landslides cause much damage to property throughout the metropolitan area of Cincinnati, Ohio. Most landslides occur in unconsolidated deposits, including colluvium, till, glacial lake clays, and man-made fill derived from colluvium and glacial deposits. Landslides in thin colluvium are widespread on steeper slopes that wall the valleys of the Ohio River and its tributaries. Abundant landslides al
Authors
Rex L. Baum, Arvid M. Johnson

Hydrothermal alteration mineralogy of SOH drill holes, Kilauea East Rift Zone geothermal area, Hawaii

Thirty-eight hydrothermal minerals were identified from 356 drill-core specimens that were obtained from three Scientific Observation Holes (SOH-1, SOH-2, and SOH-4) drilled along the lower East Rift Zone (ERZ) of Kilauea Volcano, Hawaii. The minerals formed during alteration of basaltic rocks and glass by hot, circulating, waters in aquifers consisting of variable mixtures of meteoric water and s
Authors
Keith E. Bargar, Terry E.C. Keith, Frank A. Trusdell, S.R. Evans, M.L. Sykes

Pre-1980 tephra-fall deposits erupted from Mount St. Helens, Washington

More than 100 tephra-fall deposits erupted from Mount St. Helens within about the last 40,000 years are grouped into tephra sets and layers distinguished from each other chiefly by differences in mineral composition and age. The tephra deposits record a complex history of the volcano, form important time-stratigraphic markers, and provide information about probable kinds, frequencies, and magnitud
Authors
Donal R. Mullineaux

Modeling of fluidized ejecta emplacement over digital topography on Venus

The FLOW computer model of McEwen and Malin (1989) modified for application to the study of Venus fluidized ejecta blankets (FEBs) demonstrates that relatively low viscosities, yield strengths, and initial velocities are required to duplicate the observed flow paths of the outflow materials. The model calculates the velocities and simulated flow paths of gravity flows over Magellan topography. The
Authors
Jeffrey R. Johnson, Lisa R. Gaddis