California earthquakes

M1.8 earthquake 6 km W of Cobb, California

A magnitude 1.8 earthquake struck 6 km W of Cobb, California on Mon, Mar 21, 1977, 1:48 AM PST (09:48 UTC), 3 km (2 mi) below the surface.

A larger quake followed: M3.3 3 km W of Moskowite Corner, California. This one was a foreshock.

Cobb forecastMore 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
UTC
1977-03-21 09:48:27 UTC
Depth
3.3 km (2.1 mi), shallow
Epicenter
38.822° N, 122.797° 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 0.2 km horizontally, 0.5 km in depth
Magnitude uncertainty
±0.15
Depth from
From location
Station coverage gap
47°
Stations used
20

Nearest places

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

Nearby

Within 100 km, magnitude 1.5 and up: 36 in the 60 days after this one and 40 in the 30 days before it.

After

  1. 1.75 km WSW of Cobb, California · 18092 days ago · 4 km deep · 2 km away
  2. 2.18 km WSW of Cobb, California · 18091 days ago · 4 km deep · 3 km away
  3. 2.06 km S of Calistoga, California · 18091 days ago · 5 km deep · 38 km away
  4. 2.421 km NNE of Upper Lake, California · 18090 days ago · 8 km deep · 58 km away
  5. 2.46 km W of Cobb, California · 18090 days ago · 3 km deep · 1 km away
  6. 2.26 km S of Moskowite Corner, California · 18090 days ago · 12 km deep · 71 km away
  7. 1.68 km WSW of Cobb, California · 18089 days ago · 3 km deep · 3 km away
  8. 2.22 km ENE of Calpella, California · 18089 days ago · 5 km deep · 57 km away
  9. 3.33 km W of Moskowite Corner, California · 18088 days ago · 7 km deep · 65 km away
  10. 2.95 km NNE of Penngrove, California · 18087 days ago · 7 km deep · 55 km away
  11. 2.32 km ESE of Boonville, California · 18087 days ago · 8 km deep · 51 km away
  12. 2.42 km ESE of Princeton, California · 18086 days ago · 22 km deep · 94 km away
  13. 1.54 km WSW of Cobb, California · 18085 days ago · 1 km deep · 3 km away
  14. 1.77 km W of Cobb, California · 18085 days ago · 1 km deep · 1 km away
  15. 2.13 km ENE of Windsor, California · 18085 days ago · 5 km deep · 29 km away
  16. 1.87 km ESE of Geyserville, California · 18085 days ago · 6 km deep · 16 km away
  17. 2.58 km W of Cobb, California · 18085 days ago · 0 km deep · 3 km away
  18. 3.026 km N of Potter Valley, California · 18080 days ago · 11 km deep · 86 km away
  19. 1.86 km W of Cobb, California · 18080 days ago · 3 km deep · 0 km away
  20. 1.66 km W of Cobb, California · 18077 days ago · 3 km deep · 1 km away
  21. 1.97 km WSW of Kenwood, California · 18075 days ago · 9 km deep · 50 km away
  22. 2.07 km WSW of Kenwood, California · 18075 days ago · 10 km deep · 50 km away
  23. 1.74 km WSW of Cobb, California · 18074 days ago · 3 km deep · 2 km away
  24. 2.37 km WSW of Cobb, California · 18073 days ago · -1 km deep · 2 km away
  25. 1.78 km WSW of Cobb, California · 18072 days ago · 3 km deep · 3 km away
  26. 2.38 km ESE of Hopland, California · 18070 days ago · 7 km deep · 24 km away
  27. 2.04 km WNW of Cobb, California · 18066 days ago · 3 km deep · 2 km away
  28. 1.53 km N of Healdsburg, California · 18064 days ago · 5 km deep · 21 km away
  29. 1.93 km ESE of Hopland, California · 18059 days ago · 5 km deep · 28 km away
  30. 2.56 km W of Cobb, California · 18057 days ago · 4 km deep · 0 km away
  31. 1.94 km WSW of Cobb, California · 18057 days ago · 2 km deep · 3 km away
  32. 1.64 km WSW of Cobb, California · 18052 days ago · 1 km deep · 3 km away
  33. 1.62 km SE of Clear Lake Riviera, California · 18051 days ago · 1 km deep · 16 km away
  34. 1.84 km WSW of Cobb, California · 18051 days ago · 1 km deep · 2 km away
  35. 1.61 km NNW of Geyserville, California · 18046 days ago · 5 km deep · 15 km away
  36. 1.68 km WSW of Cobb, California · 18037 days ago · 3 km deep · 3 km away

Before

  1. 1.96 km W of Cobb, California · 18093 days ago · 2 km deep · 1 km away
  2. 2.40 km WSW of Larkfield-Wikiup, California · 18095 days ago · 2 km deep · 35 km away
  3. 2.721 km NNE of Upper Lake, California · 18095 days ago · 10 km deep · 56 km away
  4. 1.96 km W of Cobb, California · 18096 days ago · 3 km deep · 1 km away
  5. 1.98 km W of Saint Helena, California · 18096 days ago · 7 km deep · 41 km away
  6. 1.84 km WSW of Cobb, California · 18098 days ago · 1 km deep · 3 km away
  7. 1.74 km WSW of Cobb, California · 18098 days ago · 1 km deep · 3 km away
  8. 1.74 km WSW of Cobb, California · 18098 days ago · 1 km deep · 3 km away
  9. 2.910 km NNE of Brooktrails, California · 18098 days ago · 3 km deep · 90 km away
  10. 2.118 km NE of Nice, California · 18101 days ago · 8 km deep · 47 km away
  11. 1.72 km SE of North Lakeport, California · 18102 days ago · 1 km deep · 29 km away
  12. 1.62 km ESE of Boonville, California · 18103 days ago · 5 km deep · 51 km away
  13. 1.7Northern California · 18104 days ago · 1 km deep · 3 km away
  14. 2.38 km WSW of Cobb, California · 18104 days ago · 0 km deep · 3 km away
  15. 1.63 km ESE of Cloverdale, California · 18105 days ago · 6 km deep · 16 km away
  16. 2.13 km ESE of Cloverdale, California · 18107 days ago · 6 km deep · 16 km away
  17. 2.43 km NNE of Santa Rosa, California · 18107 days ago · 8 km deep · 40 km away
  18. 2.07 km W of Cobb, California · 18108 days ago · 4 km deep · 1 km away
  19. 1.54 km WSW of Cobb, California · 18109 days ago · 1 km deep · 3 km away
  20. 2.711 km ESE of Hidden Valley Lake, California · 18109 days ago · 6 km deep · 32 km away

Earthquakes todayCalifornia earthquakesLive radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event nc1034479. Read Sat, Oct 3, 2026, 6:55 AM UTC.