Earthquake fault network found under Los Angeles

A policeman stands on a highway destroyed during the 1994 quake

March 4, 1999
Web posted at: 8:34 p.m. EST (0134 GMT)

From Correspondent Jim Hill

LOS ANGELES (CNN) -- With memories of the 1994 Northridge earthquake still strong, a new study has jangled the nerves of Los Angeles residents.

A research team says it has confirmed the existence of a fault network under the L.A. metro area that had only been guessed at.

"This fault system is active, as it has generated earthquakes in the past," said researcher John Shaw of Harvard University. "As a result, we suspect that it's capable of generating large and perhaps damaging earthquakes in the future."

To confirm the fault's existence, scientists used data from decades of oil well drilling in the Los Angeles area. For the first time, they determined that the fault system caused the powerful Whittier Narrows earthquake in 1987.

However, other scientists say the new findings do not mean increased quake danger for Los Angeles.

"This is a very similar picture to what we've had all along," said David Wald, a seismologist with the U.S. Geological Survey. "So the types of scenario earthquakes that we could expect haven't really changed."

But the study may help predict the strength of potential earthquakes along the fault system. Estimates range from magnitude 6.7, like the Northridge quake, to magnitude 7, more powerful than any quake in modern Los Angeles history.

"It is important to recognize that this fault system is large and capable of destructive events, and its proximity to the L.A. metro area makes it a significant threat," Shaw said.

The research doesn't help scientists answer the big question -- when might a major quake happen? That remains guesswork, which is not very reassuring in a region crisscrossed with underground faults.

Note: Pages will open in a new browser window

External sites are not endorsed by CNN Interactive.