While an earthquake in San Francisco would be catastrophic, its effects on the nation would be comparatively limited relative to one in Los Angeles. Because the Port of Los Angeles is our major Pacific import/export port, 65% of all interstate truck traffic originates from the Los Angeles area. While diversion is possible, the disruption of the flow of trade would be immensely problematic. On November 13, there is going to be the largest earthquake drill in U.S. history in southern California.

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The Great Southern California Shakeout

Yes. The FEMA report took into account what was most likely. Apparently, they think the Big One is more likely to hit SF than LA.

The BIG one will be the Cascadia subduction zone quake centred just NW of Washington state. Forecast to be 9.75 on the richter scale, affecting Vancouver, Seattle and Portland, and it is supposed to be the most expensive natural disaster in history. Last I heard, they figured there would be a 10% chance of it happening this century.