Baja Quake Portends 'Big One' for California

The 7.2-magnitude earthquake that shook Baja California in April may have set the stage for a far more powerful quake in the not-too-distant future, according to seismologists. The quake revealed several previously unknown fault lines, and triggered big moves in others—including the Big Three of San Andreas, San Jacinto, and Elsinore, the Christian Science Monitor reports. “This earthquake was a special event,” says one researcher.

Computer models suggest the quake will precipitate a large quake along one of those Big Three lines within 3 to 30 years—it’s believed to have caused July’s 5.4-magnitude San Jacinto quake already. It was also a fascinating quake in its own right. “The surface rupture did something very weird,” the seismologist says. “It dropped the high mountains of the Sierra Cucapah down. I can’t name another example where a surface rupture is actually lowering the local topography.”