Skip to main content
U.S. flag

An official website of the United States government

Landers seismogram

1992 (approx.)

Detailed Description

The Landers sequence was recorded by the regional network of permanent seismic stations and by portable seismometers that were installed following the 23 April 1992 Joshua Tree earthquake.  Portable instruments were triggered by the mainshock and continued to record early aftershocks for the first 2000 seconds (~33 minutes) of the sequence.  This figure shows shaking in east-west, north-south, and up-down direction in the town of Morongo Valley.  The instrument additionally recorded on-scale "strong motion" data for all events.  One of the initial large aftershocks was shown to have caused additional surface rupture on the Eureka Peak fault, south of the Landers mainshock.  (Figure: Susah E. Hough, USGS)


Public Domain.