Westside Quakes Rattle Nerves : Seismology: Temblors of magnitude 3.7 and 3.0 are centered offshore. No major injuries or damage are reported.

A magnitude 3.7 earthquake centered in the Pacific Ocean two miles south of Santa Monica shook parts of Los Angeles on Sunday, setting off car alarms, rattling glasses and startling residents but causing no serious damage.

The offshore temblor, recorded at 3:01 p.m., was the strongest to shake the Los Angeles Basin since a 3.9-magnitude quake centered in Pasadena on June 29, 1992, one day after the Landers earthquake, said Kate Hutton, a seismologist with Caltech in Pasadena.

Residents felt two quick jolts along the coast from Malibu to Manhattan Beach, and as far inland as Van Nuys, Silver Lake and Gardena.

An aftershock at 10:12 p.m. registered a magnitude 3.0, according to a Caltech seismologist.

Seismologists described the first jolt as “a vertical movement.”

“It was a little shaky and then it went real big, for a good five seconds,” said Gloria Schoenwetter, who was visiting her mother in a second-floor apartment at La Cienega and Olympic boulevards. “A lot of the car alarms went off on the street. It was really shaking. It felt like the floor was going to collapse and then it stopped.”

The basin has been experiencing a period of “seismic quiet” for several years, and Sunday’s 3.7 temblor, designated as mild, did little to change that, seismologists said.

“It does not bring us out of that. It’s a little too mild,” said Caltech seismologist Egill Hauksson. An earthquake would have to measure “somewhere in the 5 to 6 range” to end the quiet period, he added.

“We had a number of big quakes from 1987 through June 20, 1991. Then, the Landers earthquake happened on June 28, 1992. Since then, things have been rather quiet. . . . Periods of lesser activity will come and go,” he said.

The Landers quake, followed by the 6.7 Big Bear Lake aftershock several hours later, measured at magnitudes ranging from 7.3 to 7.6. The quakes killed a child, injured 400 people, and damaged more than 4,000 homes and 175 businesses.

Hauksson said Sunday’s quake was probably on a Westwood extension of the Elysian Park fault system, which stretches from Whittier Narrows through Downtown Los Angeles and along the Santa Monica Mountains to the ocean.

At a Starbucks coffee shop on 7th Street and Montana Avenue in Santa Monica, the jolt sent coffee spilling onto patio tables as customers ran into the street and agitated dogs whined and tugged on their leashes.

Mike Young, a reservations agent for the J. Paul Getty Museum, was perched in his 10th-floor office in Santa Monica.

“Dust was coming down from the ceiling. There were two quick, fierce jolts and then it was all over,” Young said.

At the museum in Malibu, engineers and security guards checked the facility immediately.

“Everything was intact, so we didn’t have to freak out too much. It’s scary because it was a little close this time,” said security officer Roger Balabanow.

“We thought it was a garbage truck banging into something. Boom!” said Monica Beauford, a waitress at the Firehouse in Venice.

*

The Los Angeles City Fire Department went into earthquake emergency mode seven minutes after the temblor, sending out helicopters and fire engines to search for damage. They found none, said Fire Department spokesman Brian Humphrey.

By 4 p.m., operations had returned to normal.

To some, the quake came in fierce jolts. Others flooded the Los Angeles Fire Department with 911 calls, mistaking it for an explosion, Humphrey said.

It was one of a flurry of quakes in the Santa Monica Bay in recent years, Hutton said, although most have been of lesser magnitude.

The temblor was the strongest centered near the bay since Feb. 24, 1989, when a 3.9-magnitude quake centered offshore shook the region. Five weeks earlier, a magnitude 5.0 quake in the same region broke windows, cut off power to 100,000 people and caused three minor injuries.

Times staff writer Ken Reich contributed to this story.