Contra Costa County

Earthquakes Near Antioch, California

Real-time earthquake monitoring for Antioch and surrounding areas within 25 miles. Located in the Vallejo / Benicia / Martinez region along the Concord/Green Valley Fault.

Within 25mi

5,540

total earthquakes

30-Day Activity

162

recent earthquakes

Avg Magnitude

1.37

Max Recorded

4.5

Recent Activity Near Antioch

162 earthquakes recorded within 25 miles of Antioch in the last 30 days. The largest was M4.2.

Earthquake Risk in Antioch

Antioch is located in Contra Costa County, California, one of the most seismically active regions in the United States. The city sits within the San Francisco Bay Area, which is traversed by several major fault systems.

The nearest major fault to Antioch is the Concord/Green Valley Fault. This fault system is capable of producing earthquakes that could cause significant ground shaking in the area. Residents are encouraged to be prepared with emergency supplies and an earthquake plan.

Antioch Earthquake FAQ

Is Antioch at risk for earthquakes?

Yes, Antioch is located in Contra Costa County within the seismically active San Francisco Bay Area. The region sits near several major fault systems, including the Concord/Green Valley Fault. Scientists estimate a 72% probability of a magnitude 6.7 or greater earthquake in the Bay Area within the next 30 years.

What should I do if I feel an earthquake in Antioch?

If you feel shaking in Antioch, remember "Drop, Cover, and Hold On." Drop to your hands and knees, take cover under a sturdy desk or table, and hold on until the shaking stops. Stay away from windows, exterior walls, and anything that could fall. If you're outdoors, move away from buildings, power lines, and trees.

How do I report feeling an earthquake in Antioch?

You can report feeling an earthquake in Antioch using Bay Tremor's "Did You Feel It?" feature or through the USGS website. Your reports help scientists understand earthquake intensity distribution and improve hazard assessments for Contra Costa County.

What is the nearest fault line to Antioch?

The nearest major fault to Antioch is the Concord/Green Valley Fault. This fault is part of the San Andreas Fault system and is capable of producing significant earthquakes. Residents should maintain emergency supplies and have an earthquake preparedness plan.

How often do earthquakes occur near Antioch?

The Bay Area, including areas near Antioch, experiences hundreds of small earthquakes each year. Most are too small to feel (below magnitude 2.0), but noticeable earthquakes occur regularly. Larger earthquakes (magnitude 4.0+) that are widely felt happen several times per year across the Bay Area.

What earthquake supplies should Antioch residents have?

Antioch residents should prepare an earthquake kit containing: 3-7 days of water (1 gallon per person per day), non-perishable food, flashlight, batteries, first aid kit, medications, important documents, cash, and a battery-powered radio. Also secure heavy furniture to walls and know how to shut off gas and electricity.