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Seismic monitoring station, JRSC

The Berkeley Seismology Lab, Stanford Geophysics, U.S. Geological Survey

Summary

The Jasper Ridge seismic station (JRSC) was installed in 1994 by a team from Stanford (Robert Kovach, Geophysics), the USGS, and UC Berkeley. It is part of a network of seismic stations in northern and central California maintained and operated by the Berkeley Seismology Lab (BSL). The station consists of a highly sensitive seismometer that sits on a concrete pad inside a pre-existing cave on the west shore of Searsville Lake. The cave is overlain by 30 vertical feet of bedrock, and is sealed with a steel bulkhead door. Both of these features help make the station seismically quiet. 

JRSC is both a BSL broadband and GPS site. Broadband stations have high dynamic range and are used for earthquake early warning. Broadband seismometers are often collocated with strong-motion accelerometers in installations at or near the earth's surface. BSL also operates a network of permanent, continuously telemetered high-resolution GPS stations. At many BSL sites, including JRSC, other geophysical sensors are monitored to improve our understanding of the earth. 

The seismometer records signals in a digital format over a broad frequency band ranging from 0.008Hz to 50Hz, with an overall dynamic range of 200dB. This means that nearby magnitude 6+ earthquakes will not saturate the system, yet much smaller magnitude earthquakes (ca. M=1) can also be detected.

Data from the station are continuously transmitted to UC Berkeley and the USGS via the Jasper Ridge wireless mesh network infrastructure. The Berkeley Seismology Lab maintains a website where you can create and view seismograms from JRSC and other stations. Data are available at this website one hour after recording.

Section of the JRSC seismogram for the Dec.26, 2004 tsunami earthquake.

Project Location (Sector 30)

Visible from Trail/Road

14 - Lakeside

E - Chaparral Fire Road