Fault Runs Through Downtown L.A.

By ROBERT JABLON

Associated Press Writer

LOS ANGELES (AP) -- An earthquake fault that runs under Dodger Stadium, Central Library and thousands of buildings could create more havoc than the 1994 Northridge quake that killed 72 people and caused $25 billion in damage.

The fault could generate an earthquake of magnitude 6.5 to 6.8 but there is no way of knowing whether one is imminent, geologists said Tuesday in presenting a new study at a Geological Society of America meeting.

``It doesn't increase the overall hazard for all of downtown,'' geologist and study co-author Kerry Sieh said of the findings. ``This is simply adding detail to a hazard we already knew existed but only in very general form.''

The fault the geologists studied runs from Hollywood through East Los Angeles. It could cause more damage than the 6.7 magnitude Northridge quake because there are more older buildings in the area.

``I think this could best be called a wake-up call for downtown Los Angeles,'' said Tom Henyey, director of the Southern California Earthquake Center, which helped fund the research.

One of about two dozen in the Los Angeles region, the fault runs below the surface to as deep as 10 miles. Part of what is known as the Elysian Park system, it is 11 miles long and several miles wide.

The 1987 Whittier Narrows quake, a magnitude-5.9 temblor east of downtown, first drew attention to the fault system and alerted city residents that there are active faults ``underneath our feet,'' Sieh said.

Sieh, a geology professor at the California Institute of Technology, and Caltech graduate student Michael Oskin tried to determine the fault's level of activity by examining the growth of ``wrinkles'' in a sedimentary fold of earth that covers it like a rug.

The fold was being pushed upward at a rate of about an inch every 25 years. Using that rate and other calculations, the researchers concluded that the fault is capable of producing a quake of magnitude 6.5 to 6.8 and that the quakes could occur every 1,000 to 3,000 years.

Scientists don't know when the last one occurred, so they don't know when another large quake may come. Also unknown was whether the fault might affect nearby faults.

Previous researchers have suggested, but haven't confirmed, that such linkage might produce a magnitude-7.5 quake, releasing 30 times the energy of a Northridge-sized temblor.

Copyright 1998 Associated Press. All rights reserved.