A 4.6-magnitude earthquake jolted central California shortly before dawn Saturday, the latest in a series of quakes that have rattled the most populous US state, the US Geological Survey reported. The temblor struck at 5:32 am local time (1232 GMT) about halfway between the cities of Los Angeles and San Francisco, and 22 kilometers (14 miles) east of the town of San Simeon, site of the historic Hearst Castle built by media magnate William Randolph Hearst. The quake registered at a depth of six kilometers. A 4.7-magnitude earthquake shook the region May 23, less than a week after a pair of similar temblors rattled the highly populated southern part of the state. Geologists say an earthquake capable of causing widespread destruction is 99 percent certain of hitting California within the next 30 years. 