2 Quakes Hit Near Simi Valley

The strongest aftershock this year of the 1994 Northridge quake, a 3.9, rattled built-up areas of Simi Valley and the northwest San Fernando Valley at 11:51 a.m. Wednesday.

Caltech seismologists said the epicenter of the quake--and that of a magnitude 3.1 foreshock 22 seconds earlier--was two miles north-northeast of Chatsworth, which is the first city east of Simi Valley. It occured at a depth of 3.5 miles.

The quake was felt lightly through much of the Simi and San Fernando valleys and weakly in Santa Monica and northward along the coast. No damage or injuries were reported, although a quake of such magnitude in a built-up area normally would cause some minor breakage.

The Ventura County Fire Department ordered all of its stations to move heavy equipment outside after a Simi Valley firefighter reported feeling strong shaking, a dispatcher said.

Neither the county fire department nor the Simi valley Police Department reported receiving calls for service resulting from the quake.

“We had one phone call this morning from our chief of police and he asked if our building was still standing,” joked Simi Valley Police Sgt. Gary Collins.

A new police station is being built in Simi Valley since nearly half of the current station sunk into the ground during the Northridge quake, Collins said.

Collins described the larger of the two tremors as a “rolling sensation” that lasted about eight to 10 seconds.

It was more like a major headache to Joan Langer of Northridge, who returned home from a morning arts class to find broken glass scattered across the dining room floor of her neatly kept home.

Two glass shelves in the family’s china cabinet had collapsed, loosing a cascade of fragile collectibles and a flood of bad memories.

“Last time, we lost all of the crystal we brought from Ireland,” said Langer, recalling the extensive damage her home sustained in the ’94 shaker. “Two Lladro statuettes that they didn’t get last time, they got this time.

“I guess some people just aren’t meant to have glass.”

Elsewhere in the Chatsworth-Northridge area, residents and merchants reported that the twin temblors rattled more nerves than pottery.

“When the Northridge quake happened, everything was on the floor completely,” said Dana DelBoccio, manager of the Aaron Brothers Art Marts store on Reseda Boulevard, which suffered no damage Wednesday.

“We’re just not looking forward to another one.”

There have been about 14,700 Northridge quake aftershocks, including 63 larger than the strongest one Wednesday, according to Caltech seismologist Kate Hutton.

But, with aftershocks occurring less frequently, Wednesday’s was the largest since a spasm of jolts reaching magnitude 5.0 hit an area between the Simi and Santa Clarita valleys last year on April 26 and 27.

Aftershocks do not diminish over time at a steady rate. There are typically spurts of activity, although fewer and fewer until they end years after the initial quake.

Wednesday’s strongest shake was about twice as powerful as a 3.7 aftershock felt on May 1. That quake was centered in a mountainous area northeast of Simi Valley, so it was not noticed nearly as much.

The Ventura County Fire Department reported a third aftershock Wednesday that registered 3.0. Fire officials said a state-issued beeper that sits in a dispatch center and sounds when an earthquake or tremor occurs went off a few minutes after the 3.9 aftershock.

Although more than four years have passed since the magnitude 6.7 Northridge disaster of Jan. 17, 1994, Hutton said it is not at all surprising that a 3.9 aftershock would occur now.

Times correspondent Holly J. Wolcott contributed to this story.