An offshore earthquake with a preliminary magnitude of 3.8 rattled the Lompoc Valley area at 4:22 a.m. Thursday.

The earthquake was described by the U.S. Geological Survey as located about six miles northwest of Point Conception, nine miles southwest of Lompoc and 29 miles southwest of Santa Maria, according to a 6 a.m. report from The Associated Press.

On its Web site that maps all quakes in California and Nevada, the USGS noted that the Thursday incident originated six miles below the Earth’s surface.

The quake registered with this Noozhawk reporter as a sharp jolt that lasted about 15 seconds and caused walls to creak.

More than 200 reports from people who felt the quake came into the USGS center in Colorado, according to USGS physicist Randy Baldwin.

Noozhawk staff writer Laurie Jervis can be reached at ljervis@noozhawk.com.