California earthquakes

M3.8 earthquake 12km NNE of Simi Valley, CA

A magnitude 3.8 earthquake struck 12km NNE of Simi Valley, CA on Mon, Jan 28, 2002, 10:08 PM PST (06:08 UTC), 14 km (9 mi) below the surface.

A larger quake followed: M4.6 33km NW of Santa Barbara Is., CA. This one was a foreshock.

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Map

Where this earthquake was located, with the others nearby. Select one for its page.

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The earthquake

Magnitude: 3.8 (ML, local (Richter)), minor
Magnitude from: Southern California Seismic Network
Local time: Mon, Jan 28, 2002, 10:08 PM PST
UTC: 2002-01-29 06:08:01 UTC
Depth: 14.0 km (8.7 mi), shallow
Epicenter: 34.365° N, 118.664° W
Region: California
Felt reports: 241
Tsunami flag: No
Status: Reviewed by a seismologist

Magnitude estimates

Different scales measure different things and differ by a few tenths. The USGS marks one as preferred, and it is the one this page uses.

Mag.	Scale	Computed by	Notes
3.8	ML, local (Richter)	Southern California Seismic Network	Preferred · Final · ±0.275 · 88 stations
3.8	ML, local (Richter)	USGS National Earthquake Information Center	Reviewed

What happened

The USGS’s account of the effects of this earthquake.

Felt (IV) at Simi Valley and Valencia; (III) at Canyon Country, Los Angeles, Santa Clarita and Woodland Hills; (II) at Castaic, Pasadena, Santa Monica and Thousand Oaks. Felt in Los Angeles and Ventura Counties.

From the USGS event page for ci9753497. U.S. Geological Survey text and figures are in the public domain.

Did you feel it?

241 people reported to the USGS what they felt; the strongest reported shaking was V, moderate shaking.

How well it is located

Reviewed by a seismologist.

Location uncertainty: About 0.3 km horizontally, 0.7 km in depth
Magnitude uncertainty: ±0.28
Depth from: From location
Station coverage gap: 22°
Stations used: 74

Nearest places

Distance and direction from each place to the epicenter, with its forecast.

Nearby

Within 100 km, magnitude 1.5 and up: 192 in the 60 days after this one and 52 in the 30 days before it.

After

The first 60 of 192.

Before

Earthquakes today California earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event ci9753497 (also filed as ci09753497, usp000axcj). Read Sun, Oct 4, 2026, 8:24 PM UTC.