M1.8 earthquake 7 km WSW of Cobb, California

Magnitude

1.8 (Md, duration), micro

Magnitude from

Northern California Seismic System

Local time

Mon, Apr 4, 1983, 9:41 AM PST

UTC

1983-04-04 17:41:47 UTC

Depth

2.3 km (1.4 mi), shallow

Epicenter

38.802° N, 122.802° W

Region

California

Tsunami flag

No

Status

Reviewed by a seismologist

Location uncertainty

About 0.5 km horizontally, 0.8 km in depth

Magnitude uncertainty

±0.17

Depth from

From location

Station coverage gap

71°

Stations used

12

• Cobb, CaliforniaPopulation 1,778. Forecast7 kmWSW
• Healdsburg, CaliforniaPopulation 11,742. Forecast22 kmNNE
• Santa Rosa, CaliforniaPopulation 178,127. Forecast41 kmN
• Los Angeles, CaliforniaPopulation 3,820,914. Forecast667 kmNW

After

1. 1.96 km W of Cobb, CaliforniaMon, Apr 4, 10:51 AM PST · 15888 days ago · 1 km deep · 1 km away
2. 1.59 km WSW of Cobb, CaliforniaMon, Apr 4, 2:49 PM PST · 15887 days ago · 3 km deep · 2 km away
3. 1.64 km W of Cobb, CaliforniaTue, Apr 5, 2:59 PM PST · 15886 days ago · 0 km deep · 3 km away
4. 1.77 km W of Cobb, CaliforniaWed, Apr 6, 5:22 AM PST · 15886 days ago · 3 km deep · 2 km away
5. 1.57 km W of Cobb, CaliforniaWed, Apr 6, 7:51 AM PST · 15886 days ago · 3 km deep · 2 km away
6. 1.86 km W of Cobb, CaliforniaWed, Apr 6, 12:39 PM PST · 15886 days ago · 3 km deep · 2 km away
7. 2.31 km ESE of Geyserville, CaliforniaWed, Apr 6, 1:15 PM PST · 15886 days ago · 5 km deep · 13 km away
8. 2.26 km NE of Black Point-Green Point, CaliforniaWed, Apr 6, 2:24 PM PST · 15885 days ago · 2 km deep · 78 km away
9. 1.77 km W of Cobb, CaliforniaWed, Apr 6, 6:20 PM PST · 15885 days ago · 1 km deep · 3 km away
10. 2.05 km SW of Cobb, CaliforniaWed, Apr 6, 11:20 PM PST · 15885 days ago · 0 km deep · 3 km away
11. 3.63 km E of Talmage, CaliforniaWed, Apr 6, 11:35 PM PST · 15885 days ago · 7 km deep · 47 km away
12. 1.92 km ENE of Talmage, CaliforniaThu, Apr 7, 12:10 AM PST · 15885 days ago · 4 km deep · 48 km away
13. 1.66 km W of Cobb, CaliforniaThu, Apr 7, 12:52 AM PST · 15885 days ago · 3 km deep · 1 km away
14. 2.427 km N of Potter Valley, CaliforniaThu, Apr 7, 4:16 PM PST · 15884 days ago · 3 km deep · 88 km away
15. 2.56 km W of Cobb, CaliforniaFri, Apr 8, 6:42 AM PST · 15884 days ago · 3 km deep · 2 km away
16. 2.25 km W of Cobb, CaliforniaSat, Apr 9, 9:06 PM PST · 15882 days ago · -1 km deep · 3 km away
17. 2.16 km W of Cobb, CaliforniaSun, Apr 10, 12:14 PM PST · 15882 days ago · 3 km deep · 2 km away
18. 1.68 km WSW of Cobb, CaliforniaSun, Apr 10, 11:41 PM PST · 15881 days ago · 3 km deep · 1 km away
19. 2.27 km W of Cobb, CaliforniaMon, Apr 11, 12:10 AM PST · 15881 days ago · 0 km deep · 1 km away
20. 2.46 km W of Cobb, CaliforniaMon, Apr 11, 11:29 AM PST · 15881 days ago · 3 km deep · 1 km away
21. 2.06 km W of Cobb, CaliforniaMon, Apr 11, 6:56 PM PST · 15880 days ago · 3 km deep · 3 km away
22. 2.56 km W of Cobb, CaliforniaTue, Apr 12, 9:52 AM PST · 15880 days ago · 2 km deep · 1 km away
23. 1.93 km NNE of Willows, CaliforniaWed, Apr 13, 5:50 AM PST · 15879 days ago · 19 km deep · 100 km away
24. 2.75 km SW of Cobb, CaliforniaWed, Apr 13, 6:52 AM PST · 15879 days ago · 0 km deep · 3 km away
25. 1.97 km W of Cobb, CaliforniaWed, Apr 13, 2:12 PM PST · 15878 days ago · 3 km deep · 1 km away
26. 1.68 km NNE of Larkfield-Wikiup, CaliforniaWed, Apr 13, 6:26 PM PST · 15878 days ago · 4 km deep · 26 km away
27. 1.611 km NNE of Brooktrails, CaliforniaWed, Apr 13, 9:09 PM PST · 15878 days ago · 11 km deep · 95 km away
28. 2.26 km SW of Cobb, CaliforniaWed, Apr 13, 11:48 PM PST · 15878 days ago · 1 km deep · 3 km away
29. 3.27 km WSW of Cobb, CaliforniaThu, Apr 14, 4:19 PM PST · 15877 days ago · 3 km deep · 1 km away
30. 3.07 km W of Cobb, CaliforniaThu, Apr 14, 4:21 PM PST · 15877 days ago · 2 km deep · 2 km away
31. 2.28 km WSW of Cobb, CaliforniaThu, Apr 14, 6:02 PM PST · 15877 days ago · 1 km deep · 2 km away
32. 1.95 km SW of Cobb, CaliforniaThu, Apr 14, 9:20 PM PST · 15877 days ago · 0 km deep · 3 km away
33. 2.77 km WSW of Cobb, CaliforniaFri, Apr 15, 2:53 AM PST · 15877 days ago · 2 km deep · 1 km away
34. 1.69 km W of Cobb, CaliforniaFri, Apr 15, 4:58 PM PST · 15876 days ago · 1 km deep · 3 km away
35. 1.67 km WSW of Cobb, CaliforniaSat, Apr 16, 8:01 AM PST · 15876 days ago · 1 km deep · 0 km away
36. 1.67 km WSW of Cobb, CaliforniaSun, Apr 17, 6:13 AM PST · 15875 days ago · 1 km deep · 1 km away
37. 1.922 km NE of Potter Valley, CaliforniaSun, Apr 17, 4:19 PM PST · 15874 days ago · 6 km deep · 75 km away
38. 1.97 km WSW of Cobb, CaliforniaMon, Apr 18, 9:58 AM PST · 15874 days ago · 0 km deep · 1 km away
39. 3.56 km W of Cobb, CaliforniaMon, Apr 18, 8:27 PM PST · 15873 days ago · 3 km deep · 2 km away
40. 1.85 km SW of Kenwood, CaliforniaMon, Apr 18, 10:55 PM PST · 15873 days ago · 11 km deep · 51 km away
41. 1.56 km W of Cobb, CaliforniaTue, Apr 19, 12:13 AM PST · 15873 days ago · 3 km deep · 2 km away
42. 1.94 km S of Cobb, CaliforniaTue, Apr 19, 1:12 AM PST · 15873 days ago · 1 km deep · 7 km away
43. 3.47 km WSW of Cobb, CaliforniaTue, Apr 19, 11:51 AM PST · 15873 days ago · 4 km deep · 1 km away
44. 1.57 km WSW of Cobb, CaliforniaTue, Apr 19, 12:10 PM PST · 15873 days ago · 3 km deep · 1 km away
45. 1.58 km WSW of Cobb, CaliforniaWed, Apr 20, 1:51 AM PST · 15872 days ago · 6 km deep · 1 km away
46. 1.95 km SSW of Cobb, CaliforniaWed, Apr 20, 9:57 PM PST · 15871 days ago · -1 km deep · 6 km away
47. 2.012 km ENE of Hidden Valley Lake, CaliforniaThu, Apr 21, 12:39 AM PST · 15871 days ago · 6 km deep · 33 km away
48. 3.118 km E of Potter Valley, CaliforniaThu, Apr 21, 1:01 AM PST · 15871 days ago · 10 km deep · 61 km away
49. 1.818 km E of Potter Valley, CaliforniaThu, Apr 21, 2:07 AM PST · 15871 days ago · 8 km deep · 61 km away
50. 1.65 km SW of Cobb, CaliforniaThu, Apr 21, 10:59 AM PST · 15871 days ago · 0 km deep · 3 km away
51. 2.14 km SW of Cobb, CaliforniaThu, Apr 21, 12:51 PM PST · 15871 days ago · -1 km deep · 4 km away
52. 2.04 km SSE of Clear Lake Riviera, CaliforniaThu, Apr 21, 11:34 PM PST · 15870 days ago · 3 km deep · 16 km away
53. 1.86 km W of Kenwood, CaliforniaFri, Apr 22, 1:07 AM PST · 15870 days ago · 8 km deep · 47 km away
54. 1.55 km ENE of Willits, CaliforniaFri, Apr 22, 4:29 AM PST · 15870 days ago · 3 km deep · 83 km away
55. 1.69 km ESE of Hidden Valley Lake, CaliforniaFri, Apr 22, 7:07 AM PST · 15870 days ago · 4 km deep · 30 km away
56. 1.84 km S of Cobb, CaliforniaFri, Apr 22, 6:59 PM PST · 15869 days ago · 1 km deep · 7 km away
57. 1.94 km S of Cobb, CaliforniaFri, Apr 22, 7:03 PM PST · 15869 days ago · 2 km deep · 7 km away
58. 2.56 km WSW of Cobb, CaliforniaSat, Apr 23, 11:38 AM PST · 15869 days ago · 0 km deep · 1 km away
59. 1.96 km WSW of Cobb, CaliforniaSat, Apr 23, 6:01 PM PST · 15868 days ago · 1 km deep · 1 km away
60. 1.6near the coast of Northern CaliforniaSat, Apr 23, 6:13 PM PST · 15868 days ago · 3 km deep · 57 km away

The first 60 of 134.

Before

1. 2.47 km W of Cobb, CaliforniaMon, Apr 4, 3:40 AM PST · 15888 days ago · 3 km deep · 1 km away
2. 2.97 km NW of Redwood Valley, CaliforniaMon, Apr 4, 3:26 AM PST · 15888 days ago · 0 km deep · 69 km away
3. 1.92 km ESE of Geyserville, CaliforniaSun, Apr 3, 9:43 PM PST · 15888 days ago · 6 km deep · 13 km away
4. 1.57 km W of Cobb, CaliforniaSun, Apr 3, 10:38 AM PST · 15889 days ago · -1 km deep · 1 km away
5. 1.66 km W of Cobb, CaliforniaSun, Apr 3, 3:13 AM PST · 15889 days ago · 1 km deep · 2 km away
6. 1.97 km W of Cobb, CaliforniaSat, Apr 2, 1:40 PM PST · 15889 days ago · 3 km deep · 2 km away
7. 2.110 km N of Benicia, CaliforniaFri, Apr 1, 11:31 AM PST · 15891 days ago · 12 km deep · 93 km away
8. 1.819 km SW of Cloverdale, CaliforniaTue, Mar 29, 2:27 AM PST · 15894 days ago · -1 km deep · 36 km away
9. 2.68 km ESE of Yountville, CaliforniaTue, Mar 29, 12:51 AM PST · 15894 days ago · 17 km deep · 66 km away
10. 2.13 km N of Healdsburg, CaliforniaMon, Mar 28, 1:09 PM PST · 15895 days ago · 1 km deep · 19 km away
11. 1.67 km WSW of Cobb, CaliforniaMon, Mar 28, 1:04 PM PST · 15895 days ago · 1 km deep · 1 km away
12. 2.42 km SSE of Comptche, CaliforniaSun, Mar 27, 7:27 PM PST · 15895 days ago · 10 km deep · 84 km away
13. 1.57 km W of Cobb, CaliforniaSun, Mar 27, 8:19 AM PST · 15896 days ago · 3 km deep · 2 km away
14. 2.07 km W of Cobb, CaliforniaSun, Mar 27, 4:26 AM PST · 15896 days ago · 3 km deep · 2 km away
15. 1.67 km WSW of Cobb, CaliforniaSun, Mar 27, 4:11 AM PST · 15896 days ago · 2 km deep · 1 km away
16. 2.18 km WSW of Cobb, CaliforniaSun, Mar 27, 2:16 AM PST · 15896 days ago · 7 km deep · 1 km away
17. 1.66 km WSW of Cobb, CaliforniaSun, Mar 27, 12:02 AM PST · 15896 days ago · 1 km deep · 1 km away
18. 1.56 km W of Cobb, CaliforniaFri, Mar 25, 4:55 PM PST · 15897 days ago · 1 km deep · 1 km away
19. 1.75 km E of Calpella, CaliforniaFri, Mar 25, 11:47 AM PST · 15898 days ago · 2 km deep · 56 km away
20. 1.79 km E of Hidden Valley Lake, CaliforniaFri, Mar 25, 1:07 AM PST · 15898 days ago · 1 km deep · 31 km away

From the USGS Earthquake Hazards Program and its partner networks, event nc1089947. Read Sat, Oct 3, 2026, 8:55 AM UTC.