Petrolia, Calif. – A magnitude 3.6 earthquake shook off the coast of Northern California on Saturday afternoon, centered about 27 kilometers west of Petrolia in Humboldt County. The offshore quake struck at a depth of roughly 20 kilometers, according to the U.S. Geological Survey.
According to the California Integrated Seismic Network, the tremor was recorded at 9:55 a.m. local time and was felt lightly by residents along the Humboldt coast. At least two people submitted “Did You Feel It?” reports noting mild shaking but no damage.
Communities across Humboldt Bay, including Eureka, Arcata, and Fortuna, reported the quake, though no disruptions to roads or utilities were confirmed. Local emergency officials did not issue any tsunami warnings, as the earthquake’s strength and offshore depth did not pose a coastal flooding threat.
Northern California sits on the seismically active Cascadia Subduction Zone and the Mendocino Triple Junction, where three tectonic plates meet. Small quakes are common in the region, but officials urge residents to keep emergency supplies ready in case a stronger event follows.
Seismologists noted that aftershocks are possible, though none had been reported by early Saturday afternoon. Residents are encouraged to review earthquake safety steps, including securing heavy items and having a communication plan with family members.
More updates will be issued if additional seismic activity occurs along the Humboldt coast.
