California earthquakes

M3.5 earthquake 10km NE of Milpitas, CA

A magnitude 3.5 earthquake struck 10km NE of Milpitas, CA on Sun, Sep 27, 2020, 10:16 PM PDT (05:16 UTC), 5 km (3 mi) below the surface.

Milpitas forecastMore in California

Map

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

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The earthquake

Magnitude
3.5 (Mw, moment), minor
Magnitude from
Northern California Seismic System
Local time
UTC
2020-09-28 05:16:36 UTC
Depth
4.8 km (3.0 mi), shallow
Epicenter
37.492° N, 121.829° W
Felt reports
1,428
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.ScaleComputed byNotes
3.48Mw, momentNorthern California Seismic SystemPreferred · Final · 5 stations
3.5Mwr, regional momentUSGS National Earthquake Information CenterReviewed · 5 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
726.0% of gravity
Peak ground velocity
1.4 cm/s
Map
Automatic
USGS ShakeMap: estimated shaking intensity around the epicenter
Estimated shaking intensity. Map: USGS ShakeMap.

Did you feel it?

1,428 people reported to the USGS what they felt; the strongest reported shaking was III, weak 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
3.5 Mw

How well it is located

Reviewed by a seismologist.

Location uncertainty
About 0.1 km horizontally, 0.2 km in depth
Depth from
From location
Station coverage gap
28°
Stations used
199

Nearest places

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

Nearby

Within 100 km, magnitude 1.5 and up: 85 in the 60 days after this one and 43 in the 30 days before it.

After

The first 60 of 85.

Before

Earthquakes todayCalifornia earthquakesLive radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event nc73463746 (also filed as us6000c221). Read Sun, Oct 4, 2026, 3:34 PM UTC.