Cuts Off Gas in Major Quake : Seismic Sensor Rides Wave of Success

A Van Nuys company has installed a novel earthquake-warning device in the Dorothy Chandler Pavilion at the Los Angeles Music Center, where the Academy Awards presentations are often held.

The system does not predict earthquakes. But it is designed to automatically shut off the Pavilion’s gas lines up to 72 seconds before a quake’s major jolt actually hits the building, which might prevent a fire or explosion.

The system was designed by Earthquake Safety Systems, a marketing arm of Earthquake Safety Engineering, a privately held firm that for 18 years has provided earthquake-related engineering services for nuclear power plants and other facilities. The parent firm does about $2.5 million in business a year, said Phillip Campopiano, a director in charge of sales and marketing.

Earthquake Safety is installing six or seven of its earthquake-warning systems after receiving necessary regulatory approvals 2 months ago, he said.

The Pavilion’s system cost $10,600, which includes a 2-by-3-foot control box that reads the earthquake’s signals, and another device that shuts off the gas lines that go through the building, which houses a 3,200-seat auditorium and restaurants.

Other versions of the system can cost thousands of dollars more, depending on whether additional options are ordered and on the size of the structure in which the system is used, Campopiano said.

The system works by tracking the three waves of seismic activity during an earthquake, starting with a “P” wave, which travels faster and has less physical impact than the subsequent “S” and “L” waves that can cause damage, Campopiano said.

In the case of the Pavilion, Earthquake Safety’s system is designed to evaluate the initial “P” wave and, if it indicates a damaging quake, to electronically shut off the building’s gas lines.

Earthquake Safety contends that its system cannot be triggered accidentally or be shut off by mistake.

The system is not programmed to be triggered by a minimum-size earthquake, but rather responds to more precise measures of seismic activity, Campopiano said. Still, he said the system would go off in a quake a magnitude of at least 5.4.

An early morning earthquake Dec. 4 centered in Pasadena measured 5.0. A quake in Whittier on Oct. 1, 1987, was 5.9.

Depending on where the temblor is centered, Earthquake Safety’s system will have up to 72 seconds to respond, Campopiano said. The system can also be designed to shut off other utilities and a building’s computer system, and it can trigger an audio warning that would be played over a public-address system.

The Dorothy Chandler Pavilion didn’t buy the audio-warning option, however, fearing that it could cause panic, said John Dunavent, executive vice president of Music Center Operating Co., the Pavilion’s landlord.