M1.8 earthquake 4 km S of San Andreas, California
A magnitude 1.8 earthquake struck 4 km S of San Andreas, California on Tue, Sep 15, 1981, 11:18 AM PDT (18:18 UTC), 0 km (0 mi) below the surface.
A larger quake followed: M2.5 13 km SW of Markleeville, California. This one was a foreshock.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 1.8 (md), micro
- Local time
- UTC
- 1981-09-15 18:18:57 UTC
- Depth
- -0.4 km (-0.3 mi), shallow
- Epicenter
- 38.153° N, 120.680° 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 2.1 km horizontally, 1.2 km in depth
- Magnitude uncertainty
- ±0.07
- Depth from
- From location
- Station coverage gap
- 168°
- Stations used
- 5
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 1.5 and up: 7 in the 60 days after this one and 2 in the 30 days before it.
After
- 2.513 km SW of Markleeville, California · 16434 days ago · 7 km deep · 86 km away
- 2.011 km ESE of Greeley Hill, California · 16427 days ago · 19 km deep · 77 km away
- 2.93 km ESE of Brentwood, California · 16427 days ago · 9 km deep · 89 km away
- 2.110 km SSW of Tracy, California · 16422 days ago · 9 km deep · 88 km away
- 1.917 km W of Kirkwood, California · 16416 days ago · 14 km deep · 74 km away
- 2.03 km SSE of Brentwood, California · 16412 days ago · 2 km deep · 92 km away
- 1.63 km ENE of Grayson, California · 16405 days ago · -1 km deep · 76 km away
Before
Earthquakes todayCalifornia earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event nc1067648. Read Tue, Sep 22, 2026, 9:33 PM UTC.