M 3.3 Earthquake Reported 5 km East of Colusa, California
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A minor 3.3 magnitude earthquake occurred near Colusa, California, on March 20, 2026. The tremor was recorded at a depth of 29.9 km with no tsunami threat reported.
What this USGS earthquake report tells you, and what most readers miss
This notice was issued by USGS on April 3, 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 3.28 ml occurred on March 20, 2026, at 5:26 PM UTC (10:26 AM local time). The seismic event was recorded at a depth of 29.9 km.
Location Details
The earthquake was centered at coordinates 39.2208°N, 121.9532°W, approximately 5 km east of Colusa, California. With a depth of 29.9 km, this event is classified as an intermediate-depth earthquake (20-70 km), which typically results in less intense surface shaking than shallower events.
Impact Assessment
As of the latest report, the USGS has received 14 felt reports from the public. The event registered a maximum Community Decimal Intensity (CDI) of 3.4. There is no tsunami advisory, watch, or warning in effect. No alert level color has been assigned to this event by the USGS.
What You Should Know
Earthquakes with magnitudes between 2.5 and 3.9 are classified as minor. While they are often felt by people near the epicenter, they rarely cause structural damage. Residents should remain aware of the possibility of aftershocks, which are common following seismic activity, though they are typically smaller than the initial event.
Source
Data provided by the USGS.
Original source: USGS Official Notice ↗
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