California earthquakes

M1.8 earthquake 8km NNE of Black Point-Green Point, CA

A magnitude 1.8 earthquake struck 8km NNE of Black Point-Green Point, CA on Tue, Aug 31, 2021, 2:32 PM PDT (21:32 UTC), 8 km (5 mi) below the surface.

A larger quake followed: M3.4 3km N of San Leandro, CA. This one was a foreshock.

Black Point-Green Point forecast More 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: 1.8 (Md, duration), micro
Magnitude from: Northern California Seismic System
Local time: Tue, Aug 31, 2021, 2:32 PM PDT
UTC: 2021-08-31 21:32:39 UTC
Depth: 7.8 km (4.9 mi), shallow
Epicenter: 38.176° N, 122.472° W
Region: California
Tsunami flag: No
Status: Reviewed by a seismologist

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, 0.3 km in depth
Magnitude uncertainty: ±0.22
Depth from: From location
Station coverage gap: 58°
Stations used: 33

Nearest places

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

Nearby

Within 100 km, magnitude 1.5 and up: 178 in the 60 days after this one and 73 in the 30 days before it.

After

The first 60 of 178.

Before

Earthquakes today California earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event nc73618521. Read Sun, Oct 4, 2026, 4:39 AM UTC.