California earthquakes

M3.4 earthquake 8km SW of Devore, CA

A magnitude 3.4 earthquake struck 8km SW of Devore, CA on Tue, Jun 17, 2003, 1:25 PM PDT (20:25 UTC), 3 km (2 mi) below the surface.

A larger quake followed: M4.2 34km NE of Lucerne Valley, 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: 3.4 (ML, local (Richter)), minor
Magnitude from: Southern California Seismic Network
Local time: Tue, Jun 17, 2003, 1:25 PM PDT
UTC: 2003-06-17 20:25:14 UTC
Depth: 3.3 km (2.1 mi), shallow
Epicenter: 34.177° N, 117.474° W
Region: California
Felt reports: 205
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
3.38	ML, local (Richter)	Southern California Seismic Network	Preferred · Final · ±0.363 · 99 stations
3.4	ML, local (Richter)	USGS National Earthquake Information Center	Reviewed

What happened

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

Felt (III) at Colton, Fontana, Ontario, Rancho Cucamonga, Redlands, Rialto and San Bernardino; (II) at Bloomington, Loma Linda and Riverside.

From the USGS event page for ci9923613. U.S. Geological Survey text and figures are in the public domain.

Did you feel it?

205 people reported to the USGS what they felt; the strongest reported shaking was IV, light shaking.

How well it is located

Reviewed by a seismologist.

Location uncertainty: About 0.2 km horizontally, 31.6 km in depth
Magnitude uncertainty: ±0.36
Depth from: Operator assigned
Station coverage gap: 45°
Stations used: 55

Nearest places

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

Nearby

Within 100 km, magnitude 1.5 and up: 156 in the 60 days after this one and 123 in the 30 days before it.

After

The first 60 of 156.

Before

Earthquakes today California earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event ci9923613 (also filed as ci09923613, usp000c03h). Read Mon, Oct 5, 2026, 8:34 AM UTC.