6.8-magnitude quake rattles northern California

An earthquake with a preliminary magnitude of 6.8 struck about 100 miles off the coast of Northern California Thursday morning, according to the U.S. Geological Survey.

The quake struck at 6:50 a.m. about 104 miles off the coast of Eureka. USGS initially registered the earthquake as magnitude-6.9, but downgraded it about 15 minutes later.

There were no immediate reports of damage or injuries.