(Our happy-hour fact to amaze your drinking buddies with.)

There is a 99.7 percent chance that California will be hit by an earthquake of at least magnitude 6.7 within 30 years.

The chance of a magnitude 7.5 quake is also high, at around 46 percent, according to a three-year study just released by the U.S. Geological Survey.

The numbers are derived from close studies of earlier quakes, fault lines and satellite information.

Southern California is due for a big quake, and is at more risk than the north. But San Fransisco is at risk, too, with a 63 percent chance of a 6.7 magnitude quake hitting there before 2037.

Anyone worried by the study could always head to the hills for cover. But then you'll have to deal with the wolves... Instead, it's probably best to read up on safety information from the American Red Cross, which you can find here.