California earthquakes

M1.6 earthquake 4 km SSE of Rocklin, California

A magnitude 1.6 earthquake struck 4 km SSE of Rocklin, California on Tue, Dec 31, 1985, 3:52 AM PST (11:52 UTC), 11 km (7 mi) below the surface.

A larger quake followed: M2.5 6 km ENE of Williams, California. This one was a foreshock.

Rocklin forecastMore in California

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

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The earthquake

Magnitude
1.6 (Md, duration), micro
Magnitude from
Northern California Seismic System
Local time
UTC
1985-12-31 11:52:04 UTC
Depth
11.2 km (6.9 mi), shallow
Epicenter
38.751° N, 121.219° W
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 0.5 km horizontally, 0.7 km in depth
Magnitude uncertainty
±0.39
Depth from
From location
Station coverage gap
157°
Stations used
15

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 3 in the 30 days before it.

After

  1. 1.612 km NE of Angwin, California · 14880 days ago · 11 km deep · 100 km away
  2. 1.92 km W of Country Club, California · 14879 days ago · 16 km deep · 88 km away
  3. 1.810 km NW of Moskowite Corner, California · 14870 days ago · 4 km deep · 96 km away
  4. 2.012 km N of Pittsburg, California · 14858 days ago · 16 km deep · 88 km away
  5. 2.09 km SSE of Guinda, California · 14849 days ago · 4 km deep · 80 km away
  6. 2.214 km S of Guinda, California · 14849 days ago · 11 km deep · 85 km away
  7. 2.56 km ENE of Williams, California · 14832 days ago · 4 km deep · 88 km away
  8. 1.78 km NNE of Bay Point, California · 14831 days ago · 5 km deep · 95 km away
  9. 1.85 km S of Moskowite Corner, California · 14830 days ago · 2 km deep · 94 km away

Before

  1. 4.610 km SSE of Sierra City, California · 14889 days ago · 6 km deep · 99 km away
  2. 2.03 km N of Pittsburg, California · 14897 days ago · 18 km deep · 97 km away
  3. 2.614 km NNW of Moskowite Corner, California · 14910 days ago · 3 km deep · 93 km away

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Sources

From the USGS Earthquake Hazards Program and its partner networks, event nc62498. Read Sat, Oct 3, 2026, 2:51 PM UTC.