November 28, 2025
THE GEYSERS, CA – Residents in Northern California experienced an unusual Thanksgiving morning as a swarm of at least 13 earthquakes rumbled through the region, centered near the prolific The Geysers geothermal field. The tremors, which began around 4:30 a.m. PT and concluded by 5:47 a.m. PT, ranged in magnitude from a barely perceptible 1.0 to a more noticeable 3.7.
Even as far south as San Francisco, some individuals reported feeling the ground shake, with the strongest recorded quake reaching a magnitude of 3.6. Fortunately, there have been no immediate reports of significant damage or injuries associated with the seismic activity.
The Geysers, a vast geothermal energy hub spanning Sonoma, Lake, and Mendocino counties, is a well-known hotspot for seismic events. The area is home to 18 geothermal power plants that tap into the Earth's natural steam to generate electricity. This very process, however, is often linked to the frequent tremors observed in the region.
According to experts, the extraction of steam from underground reservoirs can lead to the contraction of surrounding rock formations, building up stress. Additionally, the injection of reclaimed water into intensely hot rock to replenish steam production can cause thermal shock, further destabilizing the underground environment and triggering seismic activity.
While the swarm of Thanksgiving quakes was relatively minor, it serves as a reminder of the inherent seismic risk in California, the third-most seismically active state in the U.S., trailing only Hawaii and Alaska. Seismic experts indicate that while moderate earthquakes, like magnitude 5 events, are certainly possible in the broader region, the absence of a major, continuous fault line directly beneath The Geysers makes significantly larger earthquakes less likely.
As of the start of 2025, California has already recorded over 14,000 tremors, a testament to its dynamic geological setting. This number, while substantial, pales in comparison to the nearly 60,000 tremors recorded in Alaska during the same period, underscoring the vast scale of seismic activity across the state. The Thanksgiving morning tremors at The Geysers, while perhaps unsettling for those celebrating, are a common occurrence in a region where the Earth's power is actively harnessed.