California earthquakes

M1.9 earthquake 9 km W of Cobb, California

A magnitude 1.9 earthquake struck 9 km W of Cobb, California on Thu, Sep 20, 1984, 4:32 PM PDT (23:32 UTC), 1 km (1 mi) below the surface.

A larger quake followed: M4.3 11 km ENE of Clearlake, 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.

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The earthquake

Magnitude
1.9 (Md, duration), micro
Magnitude from
Northern California Seismic System
Local time
UTC
1984-09-20 23:32:50 UTC
Depth
0.9 km (0.6 mi), shallow
Epicenter
38.818° N, 122.827° 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 0.3 km horizontally, 0.7 km in depth
Magnitude uncertainty
±0.12
Depth from
From location
Station coverage gap
98°
Stations used
8

Nearest places

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

Nearby

Within 100 km, magnitude 1.5 and up: 166 in the 60 days after this one and 86 in the 30 days before it.

After

  1. 1.711 km SW of Hopland, California · 15353 days ago · 4 km deep · 35 km away
  2. 1.64 km SW of Cobb, California · 15352 days ago · 1 km deep · 7 km away
  3. 2.64 km NNE of Geyserville, California · 15352 days ago · 4 km deep · 10 km away
  4. 4.09 km WSW of Cobb, California · 15352 days ago · 2 km deep · 2 km away
  5. 2.07 km W of Cobb, California · 15352 days ago · -1 km deep · 1 km away
  6. 1.88 km W of Cobb, California · 15352 days ago · -1 km deep · 1 km away
  7. 2.18 km WSW of Cobb, California · 15352 days ago · 1 km deep · 2 km away
  8. 1.77 km WSW of Cobb, California · 15352 days ago · 0 km deep · 2 km away
  9. 2.24 km S of Cobb, California · 15351 days ago · 2 km deep · 10 km away
  10. 2.319 km SW of Elk Creek, California · 15351 days ago · -1 km deep · 76 km away
  11. 1.821 km ENE of Potter Valley, California · 15351 days ago · 12 km deep · 67 km away
  12. 1.54 km S of Cobb, California · 15351 days ago · 2 km deep · 10 km away
  13. 1.64 km S of Cobb, California · 15351 days ago · 1 km deep · 10 km away
  14. 1.58 km W of Cobb, California · 15351 days ago · 1 km deep · 1 km away
  15. 1.83 km SSW of Cobb, California · 15350 days ago · 1 km deep · 7 km away
  16. 1.74 km S of Cobb, California · 15350 days ago · 1 km deep · 10 km away
  17. 4.311 km ENE of Clearlake, California · 15350 days ago · 4 km deep · 34 km away
  18. 1.73 km SW of Cobb, California · 15349 days ago · 1 km deep · 7 km away
  19. 1.72 km NNE of Napa, California · 15348 days ago · 1 km deep · 74 km away
  20. 2.45 km WSW of Glen Ellen, California · 15348 days ago · 5 km deep · 56 km away
  21. 1.95 km WSW of Glen Ellen, California · 15347 days ago · 3 km deep · 57 km away
  22. 2.47 km E of Cloverdale, California · 15347 days ago · 3 km deep · 9 km away
  23. 1.713 km ESE of Hidden Valley Lake, California · 15346 days ago · 0 km deep · 36 km away
  24. 2.012 km ESE of Hidden Valley Lake, California · 15346 days ago · 12 km deep · 35 km away
  25. 1.811 km ESE of Hidden Valley Lake, California · 15346 days ago · 4 km deep · 35 km away
  26. 1.67 km E of Hidden Valley Lake, California · 15346 days ago · 6 km deep · 31 km away
  27. 1.67 km ESE of Hidden Valley Lake, California · 15346 days ago · 5 km deep · 30 km away
  28. 2.25 km ESE of Comptche, California · 15346 days ago · 0 km deep · 78 km away
  29. 1.711 km ESE of Hidden Valley Lake, California · 15346 days ago · 0 km deep · 34 km away
  30. 1.87 km ESE of Hidden Valley Lake, California · 15346 days ago · 5 km deep · 31 km away
  31. 1.815 km ESE of Hidden Valley Lake, California · 15346 days ago · 5 km deep · 38 km away
  32. 2.17 km WSW of Cobb, California · 15346 days ago · 3 km deep · 3 km away
  33. 2.04 km N of Clearlake, California · 15345 days ago · -1 km deep · 26 km away
  34. 2.07 km W of Cobb, California · 15345 days ago · 3 km deep · 1 km away
  35. 1.96 km W of Cobb, California · 15345 days ago · 3 km deep · 3 km away
  36. 2.07 km ESE of Hidden Valley Lake, California · 15345 days ago · 4 km deep · 31 km away
  37. 1.57 km SW of Calistoga, California · 15344 days ago · 5 km deep · 36 km away
  38. 1.96 km WSW of Cobb, California · 15343 days ago · 3 km deep · 3 km away
  39. 2.47 km W of Cobb, California · 15343 days ago · -1 km deep · 1 km away
  40. 1.54 km W of Cobb, California · 15343 days ago · 0 km deep · 4 km away
  41. 2.86 km W of Cobb, California · 15343 days ago · 3 km deep · 3 km away
  42. 2.45 km NW of Montalvin, California · 15341 days ago · 6 km deep · 96 km away
  43. 1.88 km NE of Hopland, California · 15340 days ago · 2 km deep · 31 km away
  44. 1.97 km W of Cobb, California · 15340 days ago · -1 km deep · 2 km away
  45. 2.94 km W of Cobb, California · 15340 days ago · 2 km deep · 5 km away
  46. 1.717 km NE of Upper Lake, California · 15339 days ago · 10 km deep · 52 km away
  47. 1.85 km SW of Cobb, California · 15339 days ago · -1 km deep · 5 km away
  48. 2.25 km SW of Cobb, California · 15339 days ago · -1 km deep · 5 km away
  49. 1.74 km WSW of Cobb, California · 15339 days ago · 1 km deep · 5 km away
  50. 2.220 km NNE of Potter Valley, California · 15338 days ago · 6 km deep · 76 km away
  51. 1.84 km S of Cobb, California · 15338 days ago · 1 km deep · 10 km away
  52. 2.32 km NE of Clear Lake Riviera, California · 15338 days ago · 0 km deep · 20 km away
  53. 1.93 km NE of Clear Lake Riviera, California · 15337 days ago · 1 km deep · 21 km away
  54. 1.82 km ENE of Clear Lake Riviera, California · 15337 days ago · 1 km deep · 20 km away
  55. 1.83 km NE of Clear Lake Riviera, California · 15337 days ago · 1 km deep · 21 km away
  56. 1.96 km W of Cobb, California · 15337 days ago · 3 km deep · 3 km away
  57. 1.97 km WSW of Cobb, California · 15337 days ago · 2 km deep · 2 km away
  58. 2.018 km ENE of Sea Ranch, California · 15336 days ago · 5 km deep · 37 km away
  59. 2.13 km NNW of Moskowite Corner, California · 15335 days ago · 0 km deep · 65 km away
  60. 1.85 km WSW of Cobb, California · 15335 days ago · 1 km deep · 4 km away

The first 60 of 166.

Before

  1. 1.68 km WSW of Cobb, California · 15354 days ago · 4 km deep · 4 km away
  2. 1.77 km SW of Calistoga, California · 15354 days ago · 5 km deep · 36 km away
  3. 1.96 km WSW of Cobb, California · 15354 days ago · 0 km deep · 5 km away
  4. 1.58 km W of Cobb, California · 15355 days ago · 0 km deep · 1 km away
  5. 1.825 km SE of Covelo, California · 15355 days ago · 5 km deep · 91 km away
  6. 1.64 km SSE of Clear Lake Riviera, California · 15355 days ago · -1 km deep · 16 km away
  7. 1.70 km WNW of Kelseyville, California · 15355 days ago · -1 km deep · 18 km away
  8. 1.724 km NNE of Potter Valley, California · 15356 days ago · 3 km deep · 79 km away
  9. 2.24 km SE of Clearlake Oaks, California · 15356 days ago · -1 km deep · 26 km away
  10. 1.55 km W of Cobb, California · 15357 days ago · 1 km deep · 4 km away
  11. 1.912 km W of Cobb, California · 15357 days ago · -1 km deep · 4 km away
  12. 2.16 km ENE of Rohnert Park, California · 15357 days ago · 4 km deep · 54 km away
  13. 1.66 km SW of Eldridge, California · 15358 days ago · 5 km deep · 60 km away
  14. 1.77 km W of Cobb, California · 15358 days ago · 2 km deep · 2 km away
  15. 1.87 km W of Cobb, California · 15358 days ago · 3 km deep · 2 km away
  16. 1.56 km WSW of Cobb, California · 15359 days ago · 3 km deep · 3 km away
  17. 2.24 km W of Vallejo, California · 15360 days ago · 8 km deep · 91 km away
  18. 4.110 km W of Philo, California · 15360 days ago · 14 km deep · 69 km away
  19. 2.1Northern California · 15360 days ago · 11 km deep · 38 km away
  20. 1.92 km ESE of Deer Park, California · 15361 days ago · 0 km deep · 47 km away

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Sources

From the USGS Earthquake Hazards Program and its partner networks, event nc28359. Read Sun, Oct 4, 2026, 6:39 AM UTC.