SAN BERNARDINO--At least six aftershocks have been recorded in the wake of Thursday night’s M4.5 earthquake. The strongest at M3.3 was felt over a more limited area. But, there was no additional damage.

An underground natural gas line outside the Arrowhead Regional Medical Center in Colton is being repaired after it ruptured. The sharp jolt knocked items from store shelves and brought down some ceiling tiles.

The jolt was centered on a section of the San Jacinto Fault. Susan Potter at the USGS says it initially was measured at M5.0.

“It takes more time to calculate its intensity which had a moment magnitude of 4.5.”

San Bernardino police say the GPS coordinates placed the exact epicenter beneath the parking lot of their ‘E’ Street station at a depth of 8.8 miles.

The quake was not related to last July’s M5.4 temblor in the Chino Hills. It was centered on a branch of the Lake Elsinore Fault known as the Yorba Linda Trend.

Story Date: January 12, 2009