California earthquakes

M3.4 earthquake 10km ESE of Willits, CA

A magnitude 3.4 earthquake struck 10km ESE of Willits, CA on Mon, Oct 19, 2020, 6:59 PM PDT (01:59 UTC), 7 km (4 mi) below the surface.

A larger quake followed: M4.4 13km W of Lakeport, CA. This one was a foreshock.

Willits forecastMore in California

Map

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

Open the live map with earthquakes

The earthquake

Magnitude
3.4 (Mw, moment), minor
Magnitude from
Northern California Seismic System
Local time
UTC
2020-10-20 01:59:46 UTC
Depth
7.0 km (4.4 mi), shallow
Epicenter
39.364° N, 123.252° W
Felt reports
19
Strongest shaking
V, moderate 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.ScaleComputed byNotes
3.43Mw, momentNorthern California Seismic SystemPreferred · Final · 3 stations
3.4Mwr, regional momentUSGS National Earthquake Information CenterReviewed · 3 stations

Shaking

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

Strongest estimated
V, moderate shaking
Peak ground acceleration
1039.0% of gravity
Peak ground velocity
2.3 cm/s
Map
Automatic
USGS ShakeMap: estimated shaking intensity around the epicenter
Estimated shaking intensity. Map: USGS ShakeMap.

Did you feel it?

19 people reported to the USGS what they felt; the strongest reported shaking was VI, strong shaking.

Did You Feel It? map: shaking reported by the public
Shaking reported by the public, by area. Map: USGS Did You Feel It?

Fault motion and ground failure

How the rock slipped, from the moment tensor, and the USGS estimate of landslides and liquefaction.

Moment magnitude
3.4 Mw

How well it is located

Reviewed by a seismologist.

Location uncertainty
About 0.1 km horizontally, 0.3 km in depth
Depth from
From location
Station coverage gap
87°
Stations used
53

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 199 in the 60 days after this one and 104 in the 30 days before it.

After

The first 60 of at least 199.

Before

Earthquakes todayCalifornia earthquakesLive radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event nc73472891 (also filed as us6000c9sf). Read Mon, Oct 5, 2026, 9:42 AM UTC.