A 3.5-magnitude earthquake struck near The Geysers geothermal region early Thursday morning, the U.S. Geological Survey reported.

The 2:57 a.m. quake was centered about a mile northwest of the steamfields, about 13 miles from Healdsburg, the USGS reported.

Seismic activity is common in and around The Geysers, causing minor earthquakes believed to be related to injection of fluids into the dry steamfields.