By Bridget Johnson, your guide to Journalism

We Californians always have quakes on our mind to some degree or another: Retrofitting. Pinning down breakables with quake putty. Not hanging heavy paintings above the bed. And with some regularity, we’re told by scientists when, and with what probability, the next big temblor is going to strike. Such was the report yesterday:

“New calculations reveal there is a 99.7 percent chance a magnitude 6.7 quake or larger will strike in the next 30 years. The odds of such an event are higher in Southern California than Northern California, 97 percent versus 93 percent.


…California is one of the world’s most seismically active regions. More than 300 faults crisscross the state, which sits atop two of Earth’s major tectonic plates, the Pacific and North American plates. About 10,000 quakes each year rattle Southern California alone, although most of them are too small to be felt.


The analysis is the first comprehensive effort by the USGS, Southern California Earthquake Center and California Geological Survey to calculate earthquake probabilities for the entire state using newly available data. Previous quake probabilities focused on specific regions and used various methodologies that made it difficult to compare.


For example, a 2003 report found the San Francisco Bay Area faced a 62 percent chance of being struck by a magnitude 6.7 quake by 2032. The new study increased the likelihood slightly to 63 percent by 2037. For the Los Angeles Basin, the probability is higher at 67 percent. There is no past comparison for the Los Angeles area.”

As the story notes, that doesn’t mean a major metropolitan area will be hit, such as 1994’s Northridge quake in the San Fernando Valley. (If you ever go past the Interstate 5/Highway 14 crossing and see the sign for the Clarence Wayne Dean Memorial Interchange, that’s dedicated to a motorcycle cop who flew off the end of the broken freeway.) California’s myriad faults — if you’ve ever traced the route of the infamous San Andreas — go through a lot of desolate areas.

Want to track the latest quakes around the world? Go to the USGS’s Earthquake Hazards Program for real-time info, and a place to report shaking if you felt it.

(1906 San Francisco quake photo from private collection)