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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
By: , , and 
https://doi.org/10.3133/ofr02203

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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.

Suggested Citation

Gibbs, J., Tinsley, J., and Boore, D.M., 2002, Borehole velocity measurements at five sites that recorded the Cape Mendocino, California earthquake of 25 April, 1992: U.S. Geological Survey Open-File Report 2002-203, 48 p., https://doi.org/10.3133/ofr02203.

ISSN: 2331-1258 (online)

Study Area

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
DOI 10.3133/ofr02203
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
Additional publication details