M1.9 earthquake 16 km ESE of Alta, California
A magnitude 1.9 earthquake struck 16 km ESE of Alta, California on Tue, Oct 20, 1981, 12:17 PM PDT (19:17 UTC), 24 km (15 mi) below the surface.
A larger quake followed: M3.3 13 km SSE of Sparks, Nevada. This one was a foreshock.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 1.9 (md), micro
- Local time
- UTC
- 1981-10-20 19:17:53 UTC
- Depth
- 23.6 km (14.7 mi), shallow
- Epicenter
- 39.167° N, 120.624° 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 1.0 km horizontally, 1.1 km in depth
- Magnitude uncertainty
- ±0.07
- Depth from
- From location
- Station coverage gap
- 246°, poorly surrounded by stations
- Stations used
- 14
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 1.5 and up: 10 in the 60 days after this one and 4 in the 30 days before it.
After
- 2.66 km N of Robbins, California · 16405 days ago · 21 km deep · 96 km away
- 3.313 km SSE of Sparks, Nevada · 16400 days ago · 2 km deep · 83 km away
- 1.87 km SSW of Kingvale, California · 16398 days ago · 14 km deep · 18 km away
- 1.95 km SSE of Sierraville, California · 16397 days ago · 4 km deep · 49 km away
- 2.17 km N of Truckee, California · 16394 days ago · 22 km deep · 45 km away
- 1.86 km NNW of Bucks Lake, California · 16389 days ago · 11 km deep · 98 km away
- 1.912 km N of Soda Springs, California · 16384 days ago · 8 km deep · 38 km away
- 1.93 km S of South Oroville, California · 16372 days ago · 11 km deep · 87 km away
- 1.910 km SSW of Markleeville, California · 16368 days ago · 0 km deep · 92 km away
- 2.12 km SE of South Oroville, California · 16362 days ago · 9 km deep · 86 km away
Before
- 1.917 km W of Kirkwood, California · 16422 days ago · 14 km deep · 57 km away
- 1.53 km E of Palermo, California · 16427 days ago · 5 km deep · 81 km away
- 3.49 km S of Dayton, Nevada · 16435 days ago · 8 km deep · 89 km away
- 2.513 km SW of Markleeville, California · 16440 days ago · 7 km deep · 87 km away
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Sources
From the USGS Earthquake Hazards Program and its partner networks, event nc1068790. Read Tue, Sep 29, 2026, 9:44 AM UTC.