Northern California Shaken by Moderate Earthquake: What Residents Need to Know
A magnitude 4.2 earthquake struck near Santa Rosa, California, on Saturday, February 21, 2026, at 9:22 am local time. The United States Geological Survey (USGS) reported the quake occurred at a shallow depth of 5.6 miles, increasing the potential for felt effects across a wider area.
Earthquake Details and Impact
The epicenter was located in Lake County, California. While a magnitude 4.2 earthquake is not typically considered major, it was likely felt by many residents in Sonoma County and surrounding areas. Preliminary reports suggest light shaking was experienced in Cobb, 3 miles from the epicenter and weak shaking in Clearlake (13 miles away) and Windsor (19 miles away).
Larger population centers, including Santa Rosa (27 miles away), Ukiah (32 miles away), Rohnert Park (34 miles away), Agua Caliente (38 miles away), Petaluma (42 miles away), and Napa (45 miles away) may have experienced very weak shaking. The USGS notes that the exact magnitude, epicenter, and depth may be revised as data is analyzed.
Understanding Shallow-Depth Earthquakes
The relatively shallow depth of this earthquake is a key factor in why it was widely felt. Shallower quakes generally cause more intense shaking at the surface compared to deeper earthquakes of the same magnitude. This is due to the fact that the seismic energy has less distance to travel before reaching populated areas.
Aftershocks and Ongoing Monitoring
Following the initial quake, aftershocks are possible. These smaller tremors occur as the Earth’s crust adjusts to the sudden release of energy. Residents should be prepared for potential aftershocks in the coming hours and days. The USGS continues to monitor the situation closely and will provide updates as they turn into available.
Preparing for Earthquakes: A California Reality
California is located in a seismically active region, making earthquakes a recurring natural hazard. Preparedness is crucial for minimizing risk. Here are some essential steps:
- Secure Your Space: Fix items that could fall during shaking, such as bookshelves and televisions.
- Create a Disaster Kit: Include essentials like water, non-perishable food, a first-aid kit, a flashlight, and a radio.
- Develop a Family Plan: Discuss what to do during an earthquake and establish a meeting point.
Volcano Discovery offers an app for both Android and iOS devices that provides fast seismic alerts.
Recent Seismic Activity in Northern California
This event follows a series of smaller earthquakes in the region. On February 20, 2026, a preliminary magnitude 3.3 earthquake was reported near Santa Rosa (NBC Bay Area). A magnitude 3.6 quake was also recorded 22 miles north of Santa Rosa earlier that morning (Volcano Discovery). A magnitude 4.0 earthquake was also reported near Santa Rosa (CBS News, BNO News, San Francisco Chronicle).
FAQ
Q: What should I do during an earthquake?
A: Drop, cover, and hold on. Get under a sturdy table or desk, and hold on until the shaking stops.
Q: What is the difference between magnitude and intensity?
A: Magnitude measures the energy released by an earthquake, while intensity measures the shaking felt at a specific location.
Q: Are aftershocks dangerous?
A: Aftershocks are generally smaller than the main earthquake, but they can still cause damage, especially to structures weakened by the initial quake.
Q: Where can I find more information about earthquakes?
A: The USGS website (https://earthquake.usgs.gov/) is an excellent resource for earthquake information.
Did you feel this earthquake? Report your experience here.
Stay informed and prepared. For the latest updates on seismic activity, visit the USGS website or download the Volcanoes & Earthquakes app.
