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Scientists Still Can't Predict the Next Loma Prieta

Two decades after the Bay Area shook for 15 seconds, scientists say they still can't predict the future

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    NEWSLETTERS

    TK
    AP
    In this Oct. 19, 1989 file photo, Workers check the damage to Interstate 880 in Oakland, Calif., after it collapsed during the Loma Prieta earthquake two days earlier. Oct. 19, 2009, marks the 20th anniversary of the Loma Prieta earthquake.

    This weekend it will have been 20 years since the Loma Prieta earthquake. In the two decades since, seismologists have seen their technology take some tremendous leaps. Especially when it comes to earthquake detection but prediction is a whole other matter.

    Some experts say the ability to accurately predict earthquakes may never become reality.

    It's remarkable that in 1989 Dr. David Oppenheimer, a United States Geological seismologist,was no more privy to what happened initially than the rest of us.

    He too had to turn to the news to get his information about the quake, unaware that the epicenter was actually miles away from San Francisco and closer to Santa Cruz.

    "That was a big problem after Loma Prieta," he said. "If you remember, there was a complete information blackout. So it took a couple days for the scope of the disaster to be understood."

    Now because of more reliable digital instruments in the field the USGS can pinpoint and post online the epicenter and magnitude of a quake within minutes of the event for anyone to see.

    Earthquake simulation technology has also seen startling advances. Today a computer can spit out a three-dimensional real time simulation of how hard the ground will shake.

    Twenty years ago it would take scientists months of number crunching to come up with a model that didn't look anything like this.

    "I think it was just a dream in 1989," Oppenheimer said. "This is what's gonna happen. You need to retrofit these buildings, tear em down, put up new buildings that can withstand this kind of shaking."

    Seismologists however don't think they'll ever be able to predict when the ground will shake.

    "We thought we'd collect enough data, we'll be able to find the precursory signals," Oppenheimer said. "We never found them. There are obviously people that feel it is possible to predict earthquakes. The mainstream field has given up."

    One prediction he will make is that Bay Area seismologists will agree when asked what keeps them up at night.

    "That's the thing that probably scares most seismologists is the Hayward fault," he said.

    The Hayward fault produces severe quakes every 140 years. It has been 141 since its last 7.0 shaker, which means it is well overdue.