01/16/1997 08:00:00

State-of-the-Art Seismic Network Receives New Funding

PASADENA—Real-time earthquake monitoring, a boon to seismic study and public safety, took a significant step forward with the recent announcement that funding had been approved for the TriNet Project, a state-of-the-art seismic monitoring network for Southern California.

The TriNet Project, a collaboration between Caltech, the United States Geological Survey, and the Division of Mines and Geology of the state Department of Conservation (DOC), gets the bulk of its $20.75 million funding from the Federal Emergency Management Agency through the Governor's Office of Emergency Services.

The TriNet agencies, together with private-sector partners, are developing this new seismic network, which combines real-time earthquake data processing and advanced computer communications technology. The TriNet Project will help save lives and mitigate the social impact of major earthquakes in Southern California.

The total cost of the project is $20.75 million. FEMA will provide $12.75 million, the USGS has provided $4.0 million, and the balance is to be matched by Caltech ($2.5 million) and the DOC ($1.75 million). Several private-sector partners, including GTE and Pacific Bell, are assisting Caltech with matching funds for its portion of the TriNet balance.

The TriNet Project will produce several new products and will distribute them through the Internet and other electronic communication channels. These products will include a

o Quick map of potentially damaging ground shaking (ShakeMap) from up to 650 instruments

o Data base needed for improvement of building codes. A central benefit of the TriNet Project will be the improvement of seismic provisions of building codes and standards. In addition, the TriNet Project is the first step towards a prototype earthquake early warning system for Southern California. Ground motion information will be rapidly recorded and communicated almost instantaneously through electronic communication channels.

Seismic waves travel at the speed of a few kilometers per second, so the rapid determination of earthquake information can serve as an early warning to distant locations in the Los Angeles area that an earthquake is on the way. This is the situation for Los Angeles with respect to the San Andreas fault where a 30-to-60-second warning could be given before the heavy shaking from a San Andreas earthquake begins in Los Angeles.

The TriNet Project is being built upon existing networks and collaborations. Southern California's first digital network began with the group of seismographs known as TERRAscope, and was made possible by a grant from the L.K. Whittier Foundation and the ARCO Foundation. Also, Pacific Bell through its CalREN Program has provided new frame-relay digital communications technology.

A major step in modernization came in response to the Northridge earthquake, when the USGS received $4.0 million from funds appropriated by Congress for the National Earthquake Hazard Reduction Program. This money constituted the first step in the TriNet project, and the USGS has been working with Caltech for the last 27 months to begin design and implementation. Significant progress has already been made, and new instrumentation is now operational.

o Thirty state-of-the-art digital seismic stations are operating with continuous communication with Caltech/USGS.

o Twenty strong-motion sites are installed near critical structures.

o Two high-rise buildings have been instrumented.

o Alarm and processing software have been designed and implemented.

o Automated contour maps of ground shaking are available on the Web within a few minutes after earthquakes (http://www-socal.wr.usgs.gov).

DOC's strong-motion network in Southern California is a key component of the TriNet Project, contributing 400 of the network's 650 sensing stations. DOC's network expansion and upgrade through the funding of this project will allow much better information about strong shaking than was possible for the Northridge earthquake. This data is the key to improving building codes for earthquake-resistant structures.

Written by Robert Tindol