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Borehole velocity measurements at five sites that recorded the Cape Mendocino, California earthquake of 25 April, 1992

Open-File Report 2002-203

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Abstract

The U.S. Geological Survey (USGS), as part of an ongoing program to acquire seismic velocity and geologic data at locations that recorded strong-ground motions during earthquakes, has investigated five sites in the Fortuna, California region (Figure 1). We selected drill sites at strong-motion stations that recorded high accelerations (Table 1) from the Cape Mendocino earthquake (M 7.0) of 25 April 1992 (Oppenheimer et al., 1993). The boreholes were drilled to a nominal depth of 95 meters (310 ft) and cased with schedule 80 pvc-casing grouted in place at each location. S-wave and P-wave data were acquired at each site using a surface source and a borehole three-component geophone. This report contains the velocity models interpreted from the borehole data and gives reference to locations and peak accelerations at the selected strong-motion stations.

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Additional Publication Details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
Borehole velocity measurements at five sites that recorded the Cape Mendocino, California earthquake of 25 April, 1992
Series title:
Open-File Report
Series number:
2002-203
Year Published:
2002
Language:
English
Publisher:
U.S. Geological Survey
Publisher location:
Reston, VA
Contributing office(s):
Earthquake Science Center
Description:
48 p.
Country:
United States
State:
California
Additional Online Files(Y/N):
N