A strong earthquake jolted Northern California on Monday, causing San Francisco skyscrapers to sway and briefly halting commuter trains, but there were no immediate reports of damage or injury. The state Office of Emergency Services in Sacramento said the quake hit 5.2 on the Richter scale, while the U.S. Geological Survey office in Menlo Park said the quake registered 5.0. The epicenter, USGS spokeswoman Pat Jorgenson said, was about 16 miles south of San Jose, along the San Andreas Fault. The time was set at 11:43 a.m., she added. There were no indications of injury or damage, San Jose police said. The quake was felt over a large area, extending from Santa Rosa, about 60 miles north of San Francisco, to the Santa Cruz area 70 miles to the south. The temblor lasted up to 10 seconds in many areas. The 38 trains running on Bay Area Rapid Transit lines were halted briefly to allow a check for track damage and then allowed to resume operation. ``It hit real hard like something going into the side of the building. Nothing fell, but light standards swayed back and forth,'' said Tom Honig, city editor of the Santa Cruz Sentinel. Walt Glines, news editor of The Dispatch in Gilroy, said half the workers in the newspaper's city room ``didn't even notice'' the rolling quake, which he said seemed to hit that area in two waves. ``The first time, I thought it was a caffeine rush. But when the second one hit, I knew,'' he said. A South San Francisco police dispatcher, who identified herself only as Pat, said her department had received a few calls, but none reporting damage. ``I sure felt it,'' she said. ``There were two shocks.'' The Richter scale is a gauge of the energey released by an earthquake, as measured by ground motion recorded on a seismograph. Each increase of one number means the ground motion was 10 times greater. On Sunday, a moderate earthquake shook a wide area of Southern California, but there were no reports of serious damage. At least four people were treated for minor injuries. The temblor was felt in downtown Los Angeles and as far away as Saugus, some 70 miles northwest of the epicenter, and Palm Springs, about 70 miles to the east. It was followed by several aftershocks. The quake in Southern California, centered 3 miles north-northwest of Upland, struck at 8:04 a.m. and registered 4.5 on the Richter scale, according to Robert Finn of the California Institute of Technology Seismology Lab in Pasadena. Instruments at the U.S. Geological Survey in Golden, Colo., recorded a slightly higher reading of 4.7. Upland, in San Bernardino County, is a city of about 50,000 people located 40 miles east of Los Angeles.
