New System Will Yield Quick Data on Quakes : Seismology: With CUBE, it will take minutes to measure a temblor and pinpoint its epicenter. Response time of rescue agencies will be trimmed.

It used to be when an earthquake struck Southern California, it once took half an hour or more for seismological authorities to pinpoint its epicenter and give a preliminary magnitude. Rescue agencies, public utilities with vulnerable transmission facilities and the news media were all kept waiting.

That is changing. In the past year, a system developed by Caltech and the U. S. Geological Survey has enabled scientists to pinpoint earthquakes within five minutes. Magnitudes have usually been measured within about 13 minutes.

With recent adjustments, the magnitude, or strength, of the next big quake, is expected to be disclosed in two to four minutes, said Egill Hauksson, a Caltech seismologist. By 1994, Hauksson says, the areas of strongest shaking and greatest potential damage--which can be miles from the epicenter--may become quickly available.

The system, called CUBE, for Caltech-USGS Broadcast of Earthquakes, has been financed by several major utilities and the U. S. Naval Weapons Center at China Lake. It enables scientists and clients to get data directly on a map of Southern California, which shows up on their computer terminals and displays where the earthquake has occurred and how strong it is.

Tom Heaton, head of the Geological Survey’s Pasadena office who with Hauksson is one of several people responsible for the system, says it “has to be made more reliable” before news agencies are given access to it. But in recent weeks, improvements have been occurring quickly.

Now, only the originating agencies, and those clients each putting up $25,000 a year to enhance the system and perform other seismological work, have the terminals that receive the information. However, the information has often been quickly relayed to the media by Caltech and the Geological Survey.

Eventually, Heaton said, for an investment of about $1,000 any interested party may be able to obtain the equipment necessary to receive the data directly.

The clients sponsoring the project are Southern California Gas Co., Metropolitan Water District, Los Angeles Department of Water and Power, Southern California Edison and the Santa Fe Railroad and the Navy.

Phil Bernal, emergency preparedness manager for the gas company, said the utility and Santa Fe have placed overlays of their transmission lines and rail lines over the computer maps, showing how quakes could affect their facilities.

“This allows us to allocate our resources to the impacted point rather than waiting around to figure out where to do it,” Bernal said. “I think the future holds a lot of promise.”

Caltech and the USGS, he added, have promised to provide data on the force and shaking intensities of each quake. “If we know we have a magnitude 6.0 quake with (half the force of) gravity, we’ll know very precisely where we have problems.”

As early as the Sierra Madre earthquake of last June 28, Santa Fe used information provided on its terminal to quickly shut down its lines in the quake area, pinpoint its inspections and bring its entire system back into service about two hours earlier than otherwise would have been possible.

Heaton and Hauksson said the new system relies on 220 seismographic stations scattered throughout Southern California that record the thousands of earthquakes, most of them tiny, that strike the area each year.

Each station is connected to Caltech by either a telephone line, microwave link or radio link. Once received, the signals are digitized and put into a computer, which analyzes them and determines the location and magnitude of the seismic event.

Then, Hauksson said, the computer sends a page via radio to Pacific Bell Paging, which broadcasts the message. The message can be picked up by pagers throughout the state.

Computer terminals of the system’s clients are connected to the pagers. When signals are received, the terminals display information on a map that shows Southern California and various fault lines. Meanwhile, the terminal will blink and sound a buzzer, alerting the owner.

The system’s problems have mainly related to measuring magnitude of quakes. Until a few weeks ago, only 64 of the 220 seismographic stations were attached to the Caltech computer, and the system could not automatically convey information about a quake stronger than 4.0.

When the April 22 Joshua Tree earthquake struck, its magnitude could not be calculated for almost 13 minutes, and then it was initially assessed as magnitude 6.3, rather than a 6.1.

Since then, a second computer has been connected to the first and all stations have been hooked up. It is able to analyze quake signals in a more sophisticated way and, Hauksson said, will be capable of transmitting a proper preliminary magnitude in the next quake, no matter how large, within two to four minutes.

Tracking Quakes

Under a new system that speeds information on the location and magnitude of Southern California earthquakes, 220 seismographic stations placed throughout Southern California by Caltech and the U.S. Geological Survey are connected to a Caltech computer by dedicated telephone lines, a microwave link or a radio link.

When a quake occurs, the data they collect is quickly analyzed and sent out to clients equipped with special computer screens within a few minutes, thus facilitating quick dispatch of damage control teams.