Southern California could be overdue for a major earthquake along the Grapevine north of Los Angeles, according to a sobering new study by the U.S. Geological Survey. The research found earthquakes happen there on average every 100 years.

—

The last major temblor occurred 160 years ago, a catastrophic geological event that ruptured an astonishing 185 miles of the San Andreas fault.

The land on either side of the fault has been pushing against the other at a rate of more than 1 inch a year since 1857, the researchers said, accumulating energy that will be suddenly released in a major earthquake, when the land along the fault would move by many feet. “So you expect that amount of accumulation of …