M1.7 earthquake 9 km SSE of Copperopolis, California
A magnitude 1.7 earthquake struck 9 km SSE of Copperopolis, California on Thu, Oct 6, 1983, 12:00 PM PDT (19:00 UTC), 7 km (4 mi) below the surface.
A larger quake followed: M2.6 11 km S of Yosemite Valley, California. This one was a foreshock.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 1.7 (Md, duration), micro
- Magnitude from
- Northern California Seismic System
- Local time
- UTC
- 1983-10-06 19:00:57 UTC
- Depth
- 7.2 km (4.5 mi), shallow
- Epicenter
- 37.903° N, 120.590° 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 1.5 km horizontally, 2.1 km in depth
- Magnitude uncertainty
- ±0.05
- Depth from
- From location
- Station coverage gap
- 243°, poorly surrounded by stations
- 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: 9 in the 60 days after this one and 2 in the 30 days before it.
After
- 1.99 km W of Volta, California · 15700 days ago · 6 km deep · 98 km away
- 1.57 km NE of Livermore, California · 15698 days ago · 9 km deep · 99 km away
- 1.88 km ENE of Livermore, California · 15698 days ago · 8 km deep · 99 km away
- 2.314 km S of Mountain House, California · 15695 days ago · 9 km deep · 91 km away
- 1.91 km ESE of Catheys Valley, California · 15679 days ago · 6 km deep · 69 km away
- 2.611 km S of Yosemite Valley, California · 15668 days ago · 3 km deep · 93 km away
- 1.56 km SE of Chinese Camp, California · 15653 days ago · 0 km deep · 20 km away
- 2.317 km W of Volta, California · 15647 days ago · 0 km deep · 98 km away
- 1.612 km NW of Diablo Grande, California · 15641 days ago · 3 km deep · 84 km away
Before
Earthquakes todayCalifornia earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event nc1104444. Read Thu, Oct 1, 2026, 8:10 PM UTC.