CHINO HILLS--An unmapped fault is suspected of causing Tuesday’s earthquake nine miles beneath the Los Serranos Golf Course.

The initial epicenter was near a complex of four faults. Seismologist Tom Heaton says the epicenters are shifting around beneath the Chino Hills.

“No one should be shocked over a magnitude-4 yet to come. But, generally speaking, this is a typical aftershock sequence.”

There have been more than a hundred aftershocks, most too weak to be felt.

There has been no additional damage.

Story Date: August 4, 2008