Why is California less vulnerable to tsunami? San Andreas fault

Sacramento BeeMarch 11, 2011 

Much of California is less vulnerable to the kind of tsunami wreckage caused Friday in Japan because the state's coastline is generally steeper, a University of California quake expert said.

Steven Ward, a research geophysicist at UC Santa Cruz, said there are exceptions to that statement, including the Los Angeles coastal plain, many harbor areas, and any place where a major river enters the sea, such as the Moss Landing area at Monterey Bay.

But in general, he said California's steep bluff-encrusted shore would block the kind of broad waves that swept buildings and ships far inland in Sendai, the Japanese city of 1 million people near the epicenter of today's quake.

Ironically, he said it is the San Andreas earthquake fault that keeps California's coast so steep.

"Even big waves typically can't go very far inland because you have bluffs and whatnot," said Ward. "So the actual inundation zones are fairly limited. We're lucky that way."

Even so, the 8.9-magnitude quake, which struck at 9:46 p.m. Pacific time Thursday, has caused damage in several California coastal communities as tsunami waves swept ashore today.

Crescent City experienced an 8.1-foot wave swell from the tsunami at 11:44 a.m. Friday, the largest reported so far in California. Officials evacuated about 6,000 people hours before that wave. The Associated Press reported one dead and three people missing, with lots of damage to boats and marina infrastructure.

The U.S. Coast Guard is currently searching for a man who was swept out to sea near the Klamath River in Del Norte County after he and a friend went to the coast to take pictures of incoming tsunami waves.

Read more of this story at SacBee.com

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