California earthquakes

M3.7 earthquake 14km WNW of Pinnacles, CA

A magnitude 3.7 earthquake struck 14km WNW of Pinnacles, CA on Mon, Oct 4, 2021, 4:07 PM PDT (23:07 UTC), 6 km (4 mi) below the surface.

A larger quake followed: M4.7 18km NW of San Simeon, CA. This one was a foreshock.

Gonzales 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: 3.7 (ML, local (Richter)), minor
Magnitude from: Northern California Seismic System
Local time: Mon, Oct 4, 2021, 4:07 PM PDT
UTC: 2021-10-04 23:07:48 UTC
Depth: 6.4 km (4.0 mi), shallow
Epicenter: 36.589° N, 121.289° W
Region: California
Felt reports: 531
Strongest shaking: IV, light shaking
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
3.66	ML, local (Richter)	Northern California Seismic System	Preferred · Final · ±0.165 · 115 stations
3.3	ML, local (Richter)	USGS National Earthquake Information Center	Reviewed · ±0.029 · 158 stations
4.0	Mw, moment	EW	Preliminary · ±0.4 · 4 stations

Shaking

The USGS ShakeMap: shaking estimated from seismic stations and the quake’s size, on the Modified Mercalli intensity scale.

Strongest estimated: IV, light shaking
Peak ground acceleration: 6.8% of gravity
Peak ground velocity: 0.4 cm/s
Map: Automatic

USGS ShakeMap: estimated shaking intensity around the epicenter — Estimated shaking intensity. Map: USGS ShakeMap.

Did you feel it?

531 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 0.1 km horizontally, 0.4 km in depth
Magnitude uncertainty: ±0.17
Depth from: From location
Station coverage gap: 59°
Stations used: 82

Nearest places

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

Nearby

Within 100 km, magnitude 1.5 and up: 146 in the 60 days after this one and 52 in the 30 days before it.

After

The first 60 of 146.

Before

Earthquakes today California earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event nc73633396 (also filed as ew1633388870, us6000frqd). Read Sun, Oct 4, 2026, 6:34 AM UTC.