MENLO PARK (KCBS) – Despite the many seismic improvements throughout Bay Area since Loma Prieta, most Californians remain woefully underinsured against damage from a major quake, according to a leading earthquake expert.

“From the point of view of infrastructure, and I’m talking about highways, power delivery systems, water delivery systems, we’ve really done a great job,” said Jack Boatwright, a geophysicist with the US Geological Survey.

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But the money that will be needed to rebuild after a large earthquake is effectively not there, he said.

“California is critically underinsured right now. There’s only ten percent insurance in California.”

Boatwright reflected on the strengths and weaknesses of the state’s earthquake readiness ahead of the Loma Prieta 25th anniversary later this year. That jolt 25 years that toppled freeways and a section of the Bay Bridge was a wake-up call in the Bay Area.

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“East Bay MUD, San Francisco PUC, PG&E, Caltrans and BART took all the lessons,” Boatwright said.

Now he believes the insurance industry and the California Earthquake Authority need to promote quake insurance products, given that only ten percent of Californians have some form of earthquake insurance.

“The infrastructure has done its job. The insurance industry or CEA still has to step up to the mark,” he said.

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Boatwright noted that seismologists’ models for predicting where the strongest ground shaking might occur have improved dramatically, and the cost to retrofit most homes would fall somewhere between $4,000 and $10,000.