M4.0 earthquake 5 km SW of Cobb, California

Magnitude

4.0 (md), light

Local time

Thu, Aug 8, 1985, 12:03 PM PDT

UTC

1985-08-08 19:03:11 UTC

Depth

-1.0 km (-0.6 mi), shallow

Epicenter

38.792° N, 122.778° W

Region

California

Tsunami flag

No

Status

Reviewed by a seismologist

Location uncertainty

About 0.4 km horizontally, 1.1 km in depth

Magnitude uncertainty

±0.27

Depth from

From location

Station coverage gap

34°

Stations used

36

• Cobb, CaliforniaPopulation 1,778. Forecast6 kmSW
• Healdsburg, CaliforniaPopulation 11,742. Forecast22 kmNNE
• Santa Rosa, CaliforniaPopulation 178,127. Forecast39 kmN
• Los Angeles, CaliforniaPopulation 3,820,914. Forecast665 kmNW

After

1. 2.15 km SW of Cobb, CaliforniaThu, Aug 8, 12:07 PM PDT · 15026 days ago · 0 km deep · 0 km away
2. 2.14 km NW of Redwood Valley, CaliforniaThu, Aug 8, 10:38 PM PDT · 15026 days ago · 5 km deep · 69 km away
3. 1.64 km WSW of Cobb, CaliforniaFri, Aug 9, 1:11 AM PDT · 15026 days ago · 1 km deep · 1 km away
4. 2.08 km SSW of Colusa, CaliforniaFri, Aug 9, 2:31 AM PDT · 15026 days ago · 6 km deep · 74 km away
5. 2.16 km W of Cobb, CaliforniaSat, Aug 10, 12:05 AM PDT · 15025 days ago · 3 km deep · 3 km away
6. 1.96 km W of Cobb, CaliforniaSat, Aug 10, 12:34 PM PDT · 15024 days ago · 1 km deep · 4 km away
7. 2.16 km W of Cobb, CaliforniaSat, Aug 10, 12:34 PM PDT · 15024 days ago · 0 km deep · 4 km away
8. 1.58 km WSW of Cobb, CaliforniaSat, Aug 10, 12:40 PM PDT · 15024 days ago · 4 km deep · 3 km away
9. 1.713 km N of Brooktrails, CaliforniaSat, Aug 10, 5:05 PM PDT · 15024 days ago · 6 km deep · 100 km away
10. 1.94 km W of Cobb, CaliforniaSat, Aug 10, 6:22 PM PDT · 15024 days ago · 0 km deep · 3 km away
11. 1.85 km WNW of Cobb, CaliforniaMon, Aug 12, 8:18 AM PDT · 15022 days ago · 2 km deep · 6 km away
12. 2.19 km E of Hidden Valley Lake, CaliforniaMon, Aug 12, 11:04 AM PDT · 15022 days ago · 7 km deep · 28 km away
13. 1.77 km W of Cobb, CaliforniaMon, Aug 12, 10:51 PM PDT · 15022 days ago · 0 km deep · 4 km away
14. 2.19 km WSW of Cobb, CaliforniaTue, Aug 13, 11:29 AM PDT · 15021 days ago · 1 km deep · 4 km away
15. 1.56 km W of Cobb, CaliforniaTue, Aug 13, 5:56 PM PDT · 15021 days ago · 3 km deep · 4 km away
16. 2.67 km WSW of Cobb, CaliforniaWed, Aug 14, 7:00 AM PDT · 15021 days ago · 0 km deep · 3 km away
17. 2.67 km W of Cobb, CaliforniaWed, Aug 14, 9:18 AM PDT · 15020 days ago · 3 km deep · 4 km away
18. 1.67 km WSW of Cobb, CaliforniaWed, Aug 14, 9:33 AM PDT · 15020 days ago · 0 km deep · 3 km away
19. 2.16 km WSW of Cobb, CaliforniaWed, Aug 14, 11:55 AM PDT · 15020 days ago · 4 km deep · 2 km away
20. 1.90 km ESE of Redwood Valley, CaliforniaThu, Aug 15, 12:21 AM PDT · 15020 days ago · 6 km deep · 64 km away
21. 1.69 km NE of Hopland, CaliforniaThu, Aug 15, 6:26 AM PDT · 15020 days ago · 6 km deep · 35 km away
22. 2.05 km SW of Cobb, CaliforniaThu, Aug 15, 1:47 PM PDT · 15019 days ago · 2 km deep · 0 km away
23. 2.08 km WSW of Cobb, CaliforniaFri, Aug 16, 3:32 PM PDT · 15018 days ago · 4 km deep · 3 km away
24. 2.16 km W of Cobb, CaliforniaSat, Aug 17, 12:41 AM PDT · 15018 days ago · 1 km deep · 4 km away
25. 2.022 km WSW of Williams, CaliforniaSat, Aug 17, 12:31 PM PDT · 15017 days ago · 3 km deep · 47 km away
26. 1.613 km ENE of Clearlake Oaks, CaliforniaSat, Aug 17, 6:25 PM PDT · 15017 days ago · 5 km deep · 36 km away
27. 2.03 km W of Cobb, CaliforniaSat, Aug 17, 9:26 PM PDT · 15017 days ago · 0 km deep · 4 km away
28. 1.52 km NNW of Clearlake, CaliforniaSat, Aug 17, 10:16 PM PDT · 15017 days ago · 2 km deep · 24 km away
29. 1.97 km W of Cobb, CaliforniaSun, Aug 18, 10:16 PM PDT · 15016 days ago · 3 km deep · 4 km away
30. 1.910 km SE of Hopland, CaliforniaMon, Aug 19, 12:50 PM PDT · 15015 days ago · 29 km deep · 25 km away
31. 1.87 km W of Cobb, CaliforniaMon, Aug 19, 1:45 PM PDT · 15015 days ago · 3 km deep · 4 km away
32. 1.86 km W of Cobb, CaliforniaMon, Aug 19, 1:53 PM PDT · 15015 days ago · 3 km deep · 4 km away
33. 1.66 km NNE of Cloverdale, CaliforniaMon, Aug 19, 5:12 PM PDT · 15015 days ago · 5 km deep · 19 km away
34. 1.66 km WNW of Cobb, CaliforniaMon, Aug 19, 10:35 PM PDT · 15015 days ago · 1 km deep · 5 km away
35. 2.09 km SSE of Willits, CaliforniaTue, Aug 20, 3:26 PM PDT · 15014 days ago · 6 km deep · 76 km away
36. 2.35 km W of Cobb, CaliforniaTue, Aug 20, 3:32 PM PDT · 15014 days ago · -1 km deep · 4 km away
37. 2.26 km NW of Cobb, CaliforniaTue, Aug 20, 10:19 PM PDT · 15014 days ago · -1 km deep · 8 km away
38. 2.85 km W of Cobb, CaliforniaWed, Aug 21, 1:57 AM PDT · 15014 days ago · 1 km deep · 4 km away
39. 1.65 km WSW of Cobb, CaliforniaWed, Aug 21, 2:12 PM PDT · 15013 days ago · 1 km deep · 2 km away
40. 1.76 km NE of Brooktrails, CaliforniaWed, Aug 21, 11:38 PM PDT · 15013 days ago · 7 km deep · 90 km away
41. 1.55 km SW of Cobb, CaliforniaThu, Aug 22, 3:09 AM PDT · 15013 days ago · 1 km deep · 1 km away
42. 1.55 km WSW of Cobb, CaliforniaThu, Aug 22, 12:14 PM PDT · 15012 days ago · 0 km deep · 0 km away
43. 1.85 km WSW of Cobb, CaliforniaThu, Aug 22, 12:38 PM PDT · 15012 days ago · 0 km deep · 0 km away
44. 2.07 km W of Cobb, CaliforniaThu, Aug 22, 2:22 PM PDT · 15012 days ago · 3 km deep · 4 km away
45. 1.98 km WSW of Cobb, CaliforniaFri, Aug 23, 9:08 PM PDT · 15011 days ago · 3 km deep · 3 km away
46. 2.28 km WSW of Cobb, CaliforniaFri, Aug 23, 9:14 PM PDT · 15011 days ago · 3 km deep · 3 km away
47. 2.93 km NNE of Clearlake, CaliforniaSat, Aug 24, 6:13 AM PDT · 15011 days ago · 1 km deep · 26 km away
48. 1.63 km NNE of Clearlake, CaliforniaSat, Aug 24, 7:55 AM PDT · 15010 days ago · -1 km deep · 26 km away
49. 1.97 km WSW of Cobb, CaliforniaSat, Aug 24, 9:35 AM PDT · 15010 days ago · 4 km deep · 3 km away
50. 2.05 km WNW of Cobb, CaliforniaSat, Aug 24, 6:15 PM PDT · 15010 days ago · 1 km deep · 5 km away
51. 1.96 km WSW of Cobb, CaliforniaSat, Aug 24, 7:01 PM PDT · 15010 days ago · 3 km deep · 2 km away
52. 1.63 km N of Clearlake, CaliforniaSat, Aug 24, 8:59 PM PDT · 15010 days ago · -1 km deep · 26 km away
53. 1.69 km WSW of Cobb, CaliforniaSun, Aug 25, 1:49 AM PDT · 15010 days ago · 1 km deep · 5 km away
54. 1.66 km NNE of Hopland, CaliforniaSun, Aug 25, 5:14 PM PDT · 15009 days ago · 0 km deep · 37 km away
55. 2.19 km NNW of Kenwood, CaliforniaMon, Aug 26, 4:41 AM PDT · 15009 days ago · 6 km deep · 37 km away
56. 1.67 km WSW of Cobb, CaliforniaTue, Aug 27, 1:56 AM PDT · 15008 days ago · 0 km deep · 3 km away
57. 2.113 km NNW of Moskowite Corner, CaliforniaTue, Aug 27, 9:47 AM PDT · 15007 days ago · 0 km deep · 51 km away
58. 1.86 km WSW of Cobb, CaliforniaTue, Aug 27, 6:12 PM PDT · 15007 days ago · 0 km deep · 2 km away
59. 1.86 km WSW of Cobb, CaliforniaTue, Aug 27, 6:13 PM PDT · 15007 days ago · 1 km deep · 2 km away
60. 2.20 km S of Brooktrails, CaliforniaTue, Aug 27, 11:20 PM PDT · 15007 days ago · -1 km deep · 89 km away

The first 60 of 184.

Before

1. 3.25 km SW of Cobb, CaliforniaThu, Aug 8, 12:02 PM PDT · 15026 days ago · 2 km deep · 1 km away
2. 1.66 km SW of Cobb, CaliforniaThu, Aug 8, 6:13 AM PDT · 15027 days ago · 0 km deep · 1 km away
3. 2.34 km NNE of Boonville, CaliforniaThu, Aug 8, 5:29 AM PDT · 15027 days ago · 4 km deep · 57 km away
4. 1.66 km WSW of Cobb, CaliforniaWed, Aug 7, 1:56 PM PDT · 15027 days ago · 0 km deep · 2 km away
5. 1.910 km SW of Williams, CaliforniaWed, Aug 7, 11:27 AM PDT · 15027 days ago · 15 km deep · 57 km away
6. 2.14 km WSW of Cobb, CaliforniaWed, Aug 7, 7:13 AM PDT · 15028 days ago · 1 km deep · 1 km away
7. 3.27 km W of Cobb, CaliforniaTue, Aug 6, 11:36 AM PDT · 15028 days ago · 1 km deep · 4 km away
8. 2.26 km WSW of Cobb, CaliforniaTue, Aug 6, 3:36 AM PDT · 15029 days ago · 0 km deep · 2 km away
9. 2.87 km W of Cobb, CaliforniaSun, Aug 4, 12:08 PM PDT · 15030 days ago · 3 km deep · 4 km away
10. 1.53 km SSW of Cobb, CaliforniaSat, Aug 3, 7:22 PM PDT · 15031 days ago · 1 km deep · 3 km away
11. 1.86 km E of Calpella, CaliforniaSat, Aug 3, 5:55 PM PDT · 15031 days ago · 5 km deep · 59 km away
12. 2.021 km NNE of Upper Lake, CaliforniaSat, Aug 3, 10:27 AM PDT · 15031 days ago · 6 km deep · 63 km away
13. 1.65 km WSW of Hopland, CaliforniaFri, Aug 2, 9:07 AM PDT · 15032 days ago · 5 km deep · 38 km away
14. 1.76 km W of Cobb, CaliforniaThu, Aug 1, 10:49 AM PDT · 15033 days ago · 3 km deep · 3 km away
15. 1.55 km W of Cobb, CaliforniaThu, Aug 1, 10:28 AM PDT · 15033 days ago · 0 km deep · 4 km away
16. 1.50 km SW of Redwood Valley, CaliforniaThu, Aug 1, 8:02 AM PDT · 15033 days ago · 4 km deep · 64 km away
17. 2.80 km NNE of Redwood Valley, CaliforniaThu, Aug 1, 7:57 AM PDT · 15033 days ago · 6 km deep · 64 km away
18. 1.60 km WSW of Redwood Valley, CaliforniaThu, Aug 1, 7:55 AM PDT · 15033 days ago · 7 km deep · 64 km away
19. 1.811 km NE of Potter Valley, CaliforniaThu, Aug 1, 7:55 AM PDT · 15033 days ago · 1 km deep · 71 km away
20. 1.70 km SSE of Redwood Valley, CaliforniaThu, Aug 1, 7:15 AM PDT · 15034 days ago · 6 km deep · 64 km away

From the USGS Earthquake Hazards Program and its partner networks, event nc54159. Read Tue, Sep 29, 2026, 1:59 AM UTC.