Ralph Archuleta

University of Southern California

Southern California Earthquake Center

USC 572726

4/1/91 - 1/31/98


The Portable Broadband Instrument Center (PBIC)
Southern California Earthquake Center (SCEC)

The Portable Broadband Instrument Center (PBIC) provides seismic instrumentation to SCEC investigators for specialized Center research in southern California. Having control of instruments allows for rapid redeployment of the equipment in the event of a significant southern California earthquake. Past aftershock deployments have used PBIC equipment to supplement Southern California Seismic Network (SCSN) coverage and to obtain digital records at existing strong ground motion sites. PBIC instrumentation is compatible with Incorporated Research Institutes for Seismology (IRIS) PASSCAL equipment and has been used in several cooperative projects. In addition, the PBIC develops calibration and other quality control methods for use with the recording equipment and performs routine maintenance and repairs on seismic instrumentation for other SCEC institutions

The vast majority of the PBIC equipment was used the entire year. The seismic hazard assessment phase of the Campus Laboratory Collaborative (CLC) project finished in early March freeing up the equipment for the Los Angeles Basin Passive Seismic Experiment (LABPSE) run out of UCLA by Dr. Monica Kohler. This experiment, consisting of eighteen seismic stations distributed from Seal Beach to the base of the San Gabriel Canyon, collected data to supplement the active source data collected by the LARSE project in late 1994.

Dr. Jamison Steidl of the Institute for Crustal Studies (UCSB) began his portable borehole study in January 1998. This study will investigate site responses using earthquake data recorded from sensors installed in 100m boreholes at several sites in the Los Angeles Basin.

The PBIC instruments were used by Javier Favella of Caltech to acquire data for a project that involved shaking the Millikan library, on the Caltech campus, with a large mechanical shaker mounted to the roof of the building.

Outreach programs continue to play an important role in the PBIC. Development of the PBIC World Wide Web (WWW) page has continued this past year including the addition of a java applet for calculating data collection rates and expanded vendor and equipment information. ICS researchers and the PBIC participated in seismological demonstrations at several local schools, including Isla Vista Elementary, Adams Elementary and La Colina Jr. High.