California earthquakes

M4.2 earthquake 16 km NNE of Mesa, California

A magnitude 4.2 earthquake struck 16 km NNE of Mesa, California on Tue, Jul 29, 1986, 12:11 AM PDT (07:11 UTC), 7 km (5 mi) below the surface.

A larger quake followed: M5.8 10 km NNE of Dixon Lane-Meadow Creek, California. This one was a foreshock.

Dixon Lane-Meadow Creek forecast More in California

Map

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

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The earthquake

Magnitude: 4.2 (ML, local (Richter)), light
Magnitude from: Northern California Seismic System
Local time: Tue, Jul 29, 1986, 12:11 AM PDT
UTC: 1986-07-29 07:11:58 UTC
Depth: 7.5 km (4.6 mi), shallow
Epicenter: 37.547° N, 118.439° W
Region: California
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
4.2	ML, local (Richter)	Northern California Seismic System	Preferred · Final · 2 stations
4.3	ML, local (Richter)	USGS National Earthquake Information Center	Reviewed
4.08	ML, local (Richter)	Southern California Seismic Network	Final · 10 stations

Did you feel it?

No one has reported feeling this quake to the USGS.

How well it is located

Reviewed by a seismologist.

Location uncertainty: About 0.2 km horizontally, 0.5 km in depth
Depth from: From location
Station coverage gap: 58°
Stations used: 43

Nearest places

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

Nearby

Within 100 km, magnitude 1.5 and up: at least 201 in the 60 days after this one and at least 200 in the 30 days before it.

After

The first 60 of at least 201.

Before

Earthquakes today California earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event nc89208 (also filed as ci704918, usp0002wnn). Read Sat, Oct 3, 2026, 12:19 AM UTC.