Deformation from 1973 through 1991 in the epicentral area of the 1992 Landers, California, Earthquake (Ms = 7.5)

Journal of Geophysical Research B: Solid Earth
By: , and 

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Abstract

Deformation of a 50 × 60 km trilateration network that spans the epicenter of the 1992 Landers earthquake(Ms = 7.5) was measured by seven surveys over the 19 years preceding the earthquake. Three moderate earthquakes (1979 Homestead Valley, Ms = 5.6; 1986 North Palm Springs, Ms = 6.0; and 1992 Joshua Tree, Ms = 6.1) occurred within the network during those 19 years. Here we use geodetic and seismic data to construct a dislocation model for each of the three moderate earthquakes. Coseismic changes due to these three moderate earthquakes as predicted by the dislocation models are then removed from the trilateration data. The residual geodetic changes appear to be uniform in time. We take those changes to represent secular strain accumulation. This strain accumulation clearly shows right‐lateral shear across the San Andreas fault but also suggests a northwest‐southeast extension northeast of the eastern end of the “Big Bend” of the San Andreas fault. The Landers earthquake ruptured along a north‐northwest trend across this region of northwest‐southeast extension.

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Publication type Article
Publication Subtype Journal Article
Title Deformation from 1973 through 1991 in the epicentral area of the 1992 Landers, California, Earthquake (Ms = 7.5)
Series title Journal of Geophysical Research B: Solid Earth
DOI 10.1029/93JB02029
Volume 98
Issue B11
Year Published 1993
Language English
Publisher American Geophysical Union
Contributing office(s) Earthquake Science Center
Description 8 p.
First page 19951
Last page 19958
Country United States
State California
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