The Geysers, California – A magnitude 4.0 earthquake struck 6 kilometers northwest of The Geysers just before 1 a.m. Thursday, part of a sharp increase in seismic activity that rattled parts of Northern California in the early morning hours.
According to the U.S. Geological Survey, at least six measurable earthquakes hit the region between 12:48 a.m. and 2 a.m., all centered near The Geysers in Lake County. Magnitudes ranged from 2.6 to 4.0, with shallow depths averaging around 3 kilometers. The 4.0 quake was the largest of the sequence, and its shallow depth likely made it more noticeable to residents. At least four people submitted “Did You Feel It?” reports as of early Thursday.
The Geysers, home to one of the world’s largest geothermal fields, is known for frequent seismic activity. However, a tightly clustered swarm like this could signal increased movement along nearby fault structures. No damage has been reported, but state geologists are monitoring for signs of escalation.
Residents near Middletown, Cobb, and Mercuryville are advised to secure heavy furniture, check emergency kits, and stay tuned for alerts. While small swarms are common, experts warn that occasional moderate quakes in this area can precede larger events.
Seismic monitors will remain active through the weekend. No official earthquake warning has been issued, but local agencies are urging awareness in case activity continues.
