A top seismology expert this week reminded Southern California that a major earthquake on the southern San Andreas fault is long overdue. But exactly what kind of quake, of course, is impossible to know. Speaking at an earthquake conference this week in Long Beach, Thomas Jordan, director of the Southern California Earthquake Center, said the infamous fault was “locked, loaded and ready to roll.”

Here is what we know on what a massive quake might look like. A magnitude-8 earthquake striking the southern San Andreas fault would cause massive shaking across a wide swath of Southern California from Monterey County to beyond the Mexican border. READ MORE