Overview

• Since just after midnight on August 14, at least 131 earthquakes have struck near The Geysers, with the largest measuring magnitude 4.0.
• Seismologists have documented over 85 aftershocks concentrated at depths of 2–4 kilometers consistent with the geothermal reservoir.
• USGS scientists describe the activity as a swarming sequence and warn that disturbing local faults raises the odds of more tremors.
• Nearby residents reported light shaking and no significant damage or injuries have been recorded.
• The Geysers field’s long history of induced seismicity stems from steam extraction and water reinjection while major regional faults remain the primary long-term hazard.