California earthquakes

M1.7 earthquake 8 km W of Cobb, California

A magnitude 1.7 earthquake struck 8 km W of Cobb, California on Fri, Oct 21, 1977, 4:05 AM PDT (11:05 UTC), 1 km (0 mi) below the surface.

A larger quake followed: M4.8 8 km E of Willits, 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
1.7 (Md, duration), micro
Magnitude from
Northern California Seismic System
Local time
UTC
1977-10-21 11:05:47 UTC
Depth
0.7 km (0.4 mi), shallow
Epicenter
38.815° N, 122.825° 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, 0.3 km in depth
Magnitude uncertainty
±0.23
Depth from
From location
Station coverage gap
54°
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: 96 in the 60 days after this one and 36 in the 30 days before it.

After

  1. 1.54 km S of Clear Lake Riviera, California · 17880 days ago · 1 km deep · 14 km away
  2. 2.35 km SW of Glen Ellen, California · 17880 days ago · 10 km deep · 58 km away
  3. 2.116 km NE of Lucerne, California · 17878 days ago · 7 km deep · 46 km away
  4. 2.15 km SW of Clearlake, California · 17876 days ago · 3 km deep · 18 km away
  5. 1.56 km W of Cobb, California · 17875 days ago · 0 km deep · 3 km away
  6. 2.17 km W of Cobb, California · 17875 days ago · 0 km deep · 2 km away
  7. 1.57 km WSW of Cobb, California · 17874 days ago · 1 km deep · 2 km away
  8. 2.27 km E of Cloverdale, California · 17872 days ago · 2 km deep · 9 km away
  9. 1.712 km ESE of Angwin, California · 17871 days ago · 9 km deep · 54 km away
  10. 2.14 km S of Willows, California · 17870 days ago · 21 km deep · 92 km away
  11. 1.88 km S of Calistoga, California · 17870 days ago · 6 km deep · 40 km away
  12. 3.58 km S of Green Valley, California · 17870 days ago · 0 km deep · 92 km away
  13. 1.811 km NE of Healdsburg, California · 17870 days ago · 5 km deep · 16 km away
  14. 2.01 km E of Larkfield-Wikiup, California · 17868 days ago · 4 km deep · 34 km away
  15. 2.01 km ESE of Larkfield-Wikiup, California · 17868 days ago · 4 km deep · 35 km away
  16. 1.611 km NE of Healdsburg, California · 17867 days ago · 5 km deep · 16 km away
  17. 2.36 km W of Cobb, California · 17867 days ago · -1 km deep · 2 km away
  18. 2.05 km NE of Ukiah, California · 17866 days ago · 0 km deep · 51 km away
  19. 2.611 km NE of Healdsburg, California · 17863 days ago · 5 km deep · 16 km away
  20. 2.411 km NE of Healdsburg, California · 17863 days ago · 5 km deep · 16 km away
  21. 2.511 km NE of Healdsburg, California · 17863 days ago · 5 km deep · 16 km away
  22. 1.711 km NE of Healdsburg, California · 17863 days ago · 5 km deep · 16 km away
  23. 2.111 km NE of Healdsburg, California · 17863 days ago · 3 km deep · 16 km away
  24. 2.411 km NE of Healdsburg, California · 17863 days ago · 4 km deep · 16 km away
  25. 2.46 km WSW of Cobb, California · 17863 days ago · 0 km deep · 3 km away
  26. 3.19 km SSW of Willows, California · 17862 days ago · 19 km deep · 87 km away
  27. 1.66 km W of Cobb, California · 17861 days ago · 3 km deep · 2 km away
  28. 3.019 km WSW of Stonyford, California · 17860 days ago · 15 km deep · 52 km away
  29. 1.610 km ENE of Healdsburg, California · 17859 days ago · 6 km deep · 18 km away
  30. 2.27 km W of Cobb, California · 17859 days ago · 3 km deep · 2 km away
  31. 2.57 km W of Cobb, California · 17859 days ago · 3 km deep · 2 km away
  32. 2.07 km WSW of Cobb, California · 17858 days ago · 0 km deep · 2 km away
  33. 1.68 km W of Cobb, California · 17858 days ago · 1 km deep · 1 km away
  34. 2.56 km W of Cobb, California · 17857 days ago · -1 km deep · 2 km away
  35. 1.811 km NE of Angwin, California · 17857 days ago · 10 km deep · 46 km away
  36. 1.84 km ESE of Clear Lake Riviera, California · 17857 days ago · 5 km deep · 19 km away
  37. 1.91 km NW of Larkfield-Wikiup, California · 17854 days ago · 2 km deep · 33 km away
  38. 2.47 km W of Cobb, California · 17853 days ago · 3 km deep · 2 km away
  39. 1.90 km ESE of Clear Lake Riviera, California · 17853 days ago · 1 km deep · 18 km away
  40. 2.56 km W of Cobb, California · 17852 days ago · 3 km deep · 2 km away
  41. 1.810 km SE of Boonville, California · 17852 days ago · 5 km deep · 42 km away
  42. 1.62 km NW of Cobb, California · 17850 days ago · 1 km deep · 8 km away
  43. 4.88 km E of Willits, California · 17848 days ago · 15 km deep · 76 km away
  44. 2.24 km WSW of Moskowite Corner, California · 17847 days ago · 8 km deep · 66 km away
  45. 2.55 km ENE of Willits, California · 17847 days ago · -1 km deep · 79 km away
  46. 2.38 km NE of Willits, California · 17847 days ago · 0 km deep · 83 km away
  47. 3.46 km E of Willits, California · 17847 days ago · 11 km deep · 77 km away
  48. 3.55 km ENE of Willits, California · 17847 days ago · 1 km deep · 80 km away
  49. 2.65 km ENE of Willits, California · 17847 days ago · 2 km deep · 80 km away
  50. 3.25 km E of Willits, California · 17847 days ago · 9 km deep · 78 km away
  51. 3.45 km ENE of Willits, California · 17847 days ago · 4 km deep · 79 km away
  52. 3.34 km E of Willits, California · 17847 days ago · 10 km deep · 78 km away
  53. 3.05 km ENE of Willits, California · 17847 days ago · 13 km deep · 79 km away
  54. 2.59 km ESE of Willits, California · 17847 days ago · 0 km deep · 74 km away
  55. 2.46 km ESE of Willits, California · 17847 days ago · 5 km deep · 76 km away
  56. 2.64 km ESE of Willits, California · 17847 days ago · 5 km deep · 77 km away
  57. 3.45 km ENE of Willits, California · 17847 days ago · 2 km deep · 80 km away
  58. 2.55 km ENE of Willits, California · 17846 days ago · 1 km deep · 79 km away
  59. 2.85 km NE of Willits, California · 17845 days ago · 2 km deep · 82 km away
  60. 2.51 km NE of Willits, California · 17845 days ago · 1 km deep · 81 km away

The first 60 of 96.

Before

  1. 1.96 km SW of Glen Ellen, California · 17881 days ago · 7 km deep · 59 km away
  2. 2.56 km W of Cobb, California · 17881 days ago · 3 km deep · 2 km away
  3. 3.35 km WSW of Glen Ellen, California · 17882 days ago · 11 km deep · 57 km away
  4. 2.02 km ESE of Clearlake, California · 17887 days ago · 5 km deep · 24 km away
  5. 1.97 km WSW of Cobb, California · 17887 days ago · 3 km deep · 2 km away
  6. 1.611 km NE of Healdsburg, California · 17887 days ago · 5 km deep · 16 km away
  7. 1.810 km NE of Healdsburg, California · 17888 days ago · 5 km deep · 17 km away
  8. 1.611 km NE of Healdsburg, California · 17889 days ago · 5 km deep · 16 km away
  9. 2.05 km W of Glen Ellen, California · 17891 days ago · 8 km deep · 55 km away
  10. 2.411 km NE of Healdsburg, California · 17892 days ago · 5 km deep · 16 km away
  11. 1.87 km W of Cobb, California · 17893 days ago · 3 km deep · 2 km away
  12. 2.210 km NE of Healdsburg, California · 17893 days ago · 6 km deep · 17 km away
  13. 3.110 km NE of Healdsburg, California · 17893 days ago · 6 km deep · 17 km away
  14. 2.26 km W of Cobb, California · 17894 days ago · 4 km deep · 3 km away
  15. 2.37 km WSW of Cobb, California · 17895 days ago · 1 km deep · 2 km away
  16. 2.06 km W of Cobb, California · 17896 days ago · 0 km deep · 2 km away
  17. 2.0Northern California · 17896 days ago · 8 km deep · 49 km away
  18. 1.58 km W of Cobb, California · 17897 days ago · 0 km deep · 1 km away
  19. 1.66 km W of Cobb, California · 17897 days ago · 4 km deep · 2 km away
  20. 2.86 km W of Cobb, California · 17899 days ago · 0 km deep · 2 km away

Earthquakes todayCalifornia earthquakesLive radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event nc1037355. Read Sun, Oct 4, 2026, 1:53 PM UTC.