M 3.4 Earthquake Recorded 6 km West of Cobb, California

Source: USGS · Northern California

Areazine synthesizes this USGS earthquake report directly from USGS's official public data feed. See our methodology for full source attribution and refresh cadence.

A minor magnitude 3.4 earthquake occurred near Cobb, California, on March 18, 2026. The shallow tremor was felt by 16 residents but did not trigger any tsunami advisories.

What this USGS earthquake report tells you, and what most readers miss

This notice was issued by USGS on April 6, 2026 and geographically references Northern California. Its severity classification of "low" signals how the issuing agency weighs the risk of harm if no action is taken - "critical" and "high" tier alerts typically carry direct consumer actions, while "medium" and "low" tend toward informational guidance or monitoring advisories. The category it belongs to - Earthquakes - determines the monitoring protocol behind it, which shapes what follow-up action (checking for structural damage, watching for aftershocks, reviewing local building codes) is relevant and which agency holds authority over the assessment.

Most readers skim a notice like this, check whether they are personally affected, and move on. The more useful lens is to verify its scope, source, and timestamp, then compare related notices without assuming that one record proves a broader trend.

Areazine pairs this record with the original agency URL so you can check the primary source before acting. Its related labels are earthquake, seismic, usgs, California.

What Happened

A minor earthquake with a magnitude of 3.36 (ml) was detected 6 km West of Cobb, California. The seismic event occurred at 05:25:32 UTC on March 18, 2026, which corresponds to 10:25:32 PM PDT on March 17 local time.

Location Details

The earthquake's epicenter was located at coordinates 38.8268°N, 122.7953°W. The tremor originated at a depth of 3.3 km, which is categorized as a shallow earthquake. Shallow events, occurring at depths of less than 20 km, are typically felt more intensely by those in the immediate vicinity than deeper seismic activity.

Impact Assessment

As of the latest report, 16 people have submitted felt reports to the USGS. There is no tsunami advisory, watch, or warning associated with this event. No specific alert level color has been issued for this tremor.

What You Should Know

Earthquakes with magnitudes between 2.5 and 3.9 are considered minor. These events are often felt by residents but rarely result in damage to buildings or infrastructure. Residents in the area should be mindful of the potential for minor aftershocks, which are common following seismic activity in this region.

Source

Data provided by the USGS Earthquake Hazards Program.

Original source: USGS Official Notice ↗

All Earthquakes →

Frequently Asked Questions

Common questions about this USGS earthquake report.

What is this USGS earthquake report about?
A minor magnitude 3.4 earthquake occurred near Cobb, California, on March 18, 2026. The shallow tremor was felt by 16 residents but did not trigger any tsunami advisories.
Which agency issued this alert?
This alert was issued by USGS. The original notice is available at the source link at the bottom of this article.
How severe is this alert?
This alert is classified as "low" severity. No immediate action required, but stay aware.
What area is affected?
This alert affects Northern California. Check with USGS for the most current geographic scope.
Where can I find more Earthquakes updates?
Browse the full Earthquakes feed on Areazine at areazine.com/earthquakes/ for the latest updates from USGS and other agencies.