M1.8 earthquake 9 km NNE of Brooktrails, California

Magnitude

1.8 (Md, duration), micro

Magnitude from

Northern California Seismic System

Local time

Thu, Apr 28, 1983, 5:02 PM PDT

UTC

1983-04-29 00:02:00 UTC

Depth

8.1 km (5.0 mi), shallow

Epicenter

39.521° N, 123.327° W

Region

California

Tsunami flag

No

Status

Reviewed by a seismologist

Location uncertainty

About 0.3 km horizontally, 0.8 km in depth

Magnitude uncertainty

±0.08

Depth from

From location

Station coverage gap

96°

Stations used

11

• Brooktrails, CaliforniaPopulation 3,235. Forecast10 kmNNE
• Ukiah, CaliforniaPopulation 15,917. Forecast43 kmNNW
• Chico, CaliforniaPopulation 121,345. Forecast130 kmW
• Los Angeles, CaliforniaPopulation 3,820,914. Forecast758 kmNW

After

1. 1.85 km W of Cobb, CaliforniaFri, Apr 29, 2:35 AM PDT · 15861 days ago · 2 km deep · 91 km away
2. 2.17 km W of Cobb, CaliforniaFri, Apr 29, 1:24 PM PDT · 15860 days ago · 3 km deep · 90 km away
3. 1.57 km W of Cobb, CaliforniaFri, Apr 29, 1:37 PM PDT · 15860 days ago · 3 km deep · 90 km away
4. 1.88 km W of Cobb, CaliforniaFri, Apr 29, 8:04 PM PDT · 15860 days ago · 3 km deep · 90 km away
5. 1.618 km NE of Upper Lake, CaliforniaSat, Apr 30, 10:03 AM PDT · 15859 days ago · 10 km deep · 54 km away
6. 1.62 km NE of Clearlake, CaliforniaSat, Apr 30, 12:21 PM PDT · 15859 days ago · -1 km deep · 87 km away
7. 1.74 km SE of Leggett, CaliforniaSat, Apr 30, 9:43 PM PDT · 15859 days ago · 7 km deep · 47 km away
8. 1.64 km SW of Cobb, CaliforniaSat, Apr 30, 10:32 PM PDT · 15859 days ago · -1 km deep · 94 km away
9. 2.032 km WNW of Paskenta, CaliforniaSun, May 1, 1:00 AM PDT · 15859 days ago · 14 km deep · 59 km away
10. 1.67 km WNW of Laytonville, CaliforniaMon, May 2, 4:08 PM PDT · 15857 days ago · 4 km deep · 29 km away
11. 2.09 km WSW of Cobb, CaliforniaTue, May 3, 10:16 PM PDT · 15856 days ago · 2 km deep · 91 km away
12. 2.47 km WSW of Cobb, CaliforniaTue, May 3, 11:44 PM PDT · 15856 days ago · 2 km deep · 91 km away
13. 1.53 km E of Hopland, CaliforniaWed, May 4, 3:28 PM PDT · 15855 days ago · 1 km deep · 65 km away
14. 1.67 km WSW of Cobb, CaliforniaThu, May 5, 6:53 AM PDT · 15855 days ago · 3 km deep · 93 km away
15. 1.67 km WSW of Cobb, CaliforniaThu, May 5, 10:11 PM PDT · 15854 days ago · 3 km deep · 93 km away
16. 1.97 km W of Laytonville, CaliforniaFri, May 6, 3:47 PM PDT · 15853 days ago · 1 km deep · 28 km away
17. 1.91 km SE of Calpella, CaliforniaFri, May 6, 9:27 PM PDT · 15853 days ago · 3 km deep · 35 km away
18. 1.62 km SE of Clear Lake Riviera, CaliforniaSat, May 7, 2:53 AM PDT · 15853 days ago · 1 km deep · 84 km away
19. 2.05 km W of Cobb, CaliforniaSat, May 7, 7:36 AM PDT · 15853 days ago · 0 km deep · 90 km away
20. 2.28 km WSW of Cobb, CaliforniaSat, May 7, 10:36 AM PDT · 15852 days ago · 3 km deep · 91 km away
21. 1.72 km SE of Clear Lake Riviera, CaliforniaSat, May 7, 1:03 PM PDT · 15852 days ago · 0 km deep · 84 km away
22. 1.618 km NE of Sea Ranch, CaliforniaSat, May 7, 9:04 PM PDT · 15852 days ago · 9 km deep · 76 km away
23. 1.77 km W of Cobb, CaliforniaSun, May 8, 9:28 AM PDT · 15851 days ago · 5 km deep · 90 km away
24. 1.922 km NNE of Potter Valley, CaliforniaSun, May 8, 7:28 PM PDT · 15851 days ago · 5 km deep · 29 km away
25. 1.524 km SE of Covelo, CaliforniaMon, May 9, 2:15 PM PDT · 15850 days ago · 5 km deep · 24 km away
26. 1.826 km N of Potter Valley, CaliforniaMon, May 9, 8:57 PM PDT · 15850 days ago · 0 km deep · 21 km away
27. 1.77 km W of Cobb, CaliforniaTue, May 10, 12:02 AM PDT · 15850 days ago · 2 km deep · 90 km away
28. 1.96 km SW of Cobb, CaliforniaThu, May 12, 4:23 AM PDT · 15848 days ago · 1 km deep · 95 km away
29. 1.99 km W of Calpella, CaliforniaSat, May 14, 1:07 AM PDT · 15846 days ago · 14 km deep · 33 km away
30. 1.76 km WSW of Cobb, CaliforniaSun, May 15, 12:47 AM PDT · 15845 days ago · 2 km deep · 93 km away
31. 1.55 km SW of Cobb, CaliforniaMon, May 16, 12:55 AM PDT · 15844 days ago · 1 km deep · 94 km away
32. 2.35 km SW of Cobb, CaliforniaTue, May 17, 9:56 AM PDT · 15842 days ago · 0 km deep · 94 km away
33. 1.65 km W of Cobb, CaliforniaTue, May 17, 12:58 PM PDT · 15842 days ago · 1 km deep · 90 km away
34. 1.87 km W of Cobb, CaliforniaTue, May 17, 11:20 PM PDT · 15842 days ago · 3 km deep · 90 km away
35. 1.86 km SW of Cobb, CaliforniaWed, May 18, 12:54 PM PDT · 15841 days ago · 3 km deep · 95 km away
36. 1.67 km WSW of Cobb, CaliforniaThu, May 19, 8:47 AM PDT · 15840 days ago · 1 km deep · 91 km away
37. 1.714 km WSW of Calpella, CaliforniaFri, May 20, 12:59 AM PDT · 15840 days ago · 2 km deep · 36 km away
38. 2.213 km SW of Willits, CaliforniaFri, May 20, 2:26 PM PDT · 15839 days ago · 0 km deep · 25 km away
39. 2.59 km WSW of Cobb, CaliforniaFri, May 20, 11:04 PM PDT · 15839 days ago · 1 km deep · 91 km away
40. 1.67 km WSW of Cobb, CaliforniaSat, May 21, 6:25 AM PDT · 15839 days ago · 1 km deep · 91 km away
41. 2.515 km N of Laytonville, CaliforniaSat, May 21, 7:57 AM PDT · 15839 days ago · 4 km deep · 37 km away
42. 2.47 km WSW of Cobb, CaliforniaSun, May 22, 7:58 AM PDT · 15838 days ago · 4 km deep · 92 km away
43. 1.67 km W of Cobb, CaliforniaSun, May 22, 12:25 PM PDT · 15837 days ago · 3 km deep · 90 km away
44. 1.66 km WSW of Cobb, CaliforniaSun, May 22, 3:19 PM PDT · 15837 days ago · 3 km deep · 91 km away
45. 1.65 km NNW of Redway, CaliforniaSun, May 22, 7:49 PM PDT · 15837 days ago · 15 km deep · 84 km away
46. 1.65 km W of Cobb, CaliforniaMon, May 23, 5:24 PM PDT · 15836 days ago · 6 km deep · 91 km away
47. 2.22 km SSE of Caspar, CaliforniaMon, May 23, 5:39 PM PDT · 15836 days ago · 6 km deep · 45 km away
48. 2.37 km WSW of Cobb, CaliforniaTue, May 24, 9:45 PM PDT · 15835 days ago · 1 km deep · 91 km away
49. 1.67 km WSW of Cobb, CaliforniaWed, May 25, 1:48 AM PDT · 15835 days ago · 2 km deep · 91 km away
50. 2.08 km WSW of Cobb, CaliforniaWed, May 25, 6:19 PM PDT · 15834 days ago · 4 km deep · 91 km away
51. 1.96 km WSW of Cobb, CaliforniaThu, May 26, 3:23 AM PDT · 15834 days ago · 1 km deep · 91 km away
52. 2.07 km W of Cobb, CaliforniaThu, May 26, 10:07 PM PDT · 15833 days ago · 3 km deep · 90 km away
53. 1.86 km W of Cobb, CaliforniaFri, May 27, 2:16 AM PDT · 15833 days ago · 4 km deep · 91 km away
54. 2.37 km W of Cobb, CaliforniaFri, May 27, 2:18 AM PDT · 15833 days ago · 3 km deep · 90 km away
55. 1.67 km W of Cobb, CaliforniaFri, May 27, 11:54 AM PDT · 15832 days ago · 1 km deep · 91 km away
56. 2.16 km E of Manchester, CaliforniaFri, May 27, 9:58 PM PDT · 15832 days ago · 11 km deep · 66 km away
57. 3.37 km W of Cobb, CaliforniaSat, May 28, 9:11 AM PDT · 15831 days ago · 3 km deep · 90 km away
58. 1.76 km W of Cobb, CaliforniaSat, May 28, 9:21 AM PDT · 15831 days ago · 2 km deep · 91 km away
59. 2.17 km WSW of Cobb, CaliforniaMon, May 30, 7:54 AM PDT · 15830 days ago · 4 km deep · 91 km away
60. 1.99 km WSW of Cobb, CaliforniaMon, May 30, 8:04 AM PDT · 15830 days ago · 2 km deep · 91 km away

The first 60 of 158.

Before

1. 2.06 km WSW of Cobb, CaliforniaThu, Apr 28, 8:19 AM PDT · 15862 days ago · 3 km deep · 92 km away
2. 2.09 km SSE of Laytonville, CaliforniaWed, Apr 27, 8:47 PM PDT · 15862 days ago · 8 km deep · 14 km away
3. 1.920 km NE of Potter Valley, CaliforniaWed, Apr 27, 12:34 PM PDT · 15862 days ago · 13 km deep · 36 km away
4. 2.07 km WSW of Cobb, CaliforniaTue, Apr 26, 11:59 PM PDT · 15863 days ago · 0 km deep · 91 km away
5. 2.110 km ENE of Cloverdale, CaliforniaTue, Apr 26, 7:05 AM PDT · 15864 days ago · 4 km deep · 85 km away
6. 2.26 km SW of Cobb, CaliforniaSun, Apr 24, 12:14 PM PDT · 15865 days ago · 0 km deep · 94 km away
7. 1.77 km WSW of Cobb, CaliforniaSun, Apr 24, 11:32 AM PDT · 15865 days ago · 3 km deep · 91 km away
8. 1.68 km SSE of Laytonville, CaliforniaSun, Apr 24, 12:10 AM PST · 15866 days ago · 9 km deep · 15 km away
9. 1.6near the coast of Northern CaliforniaSat, Apr 23, 6:13 PM PST · 15866 days ago · 3 km deep · 35 km away
10. 1.96 km WSW of Cobb, CaliforniaSat, Apr 23, 6:01 PM PST · 15866 days ago · 1 km deep · 92 km away
11. 2.56 km WSW of Cobb, CaliforniaSat, Apr 23, 11:38 AM PST · 15866 days ago · 0 km deep · 93 km away
12. 1.94 km S of Cobb, CaliforniaFri, Apr 22, 7:03 PM PST · 15867 days ago · 2 km deep · 98 km away
13. 1.84 km S of Cobb, CaliforniaFri, Apr 22, 6:59 PM PST · 15867 days ago · 1 km deep · 97 km away
14. 1.55 km ENE of Willits, CaliforniaFri, Apr 22, 4:29 AM PST · 15868 days ago · 3 km deep · 10 km away
15. 2.04 km SSE of Clear Lake Riviera, CaliforniaThu, Apr 21, 11:34 PM PST · 15868 days ago · 3 km deep · 86 km away
16. 2.14 km SW of Cobb, CaliforniaThu, Apr 21, 12:51 PM PST · 15868 days ago · -1 km deep · 95 km away
17. 1.65 km SW of Cobb, CaliforniaThu, Apr 21, 10:59 AM PST · 15868 days ago · 0 km deep · 94 km away
18. 1.818 km E of Potter Valley, CaliforniaThu, Apr 21, 2:07 AM PST · 15869 days ago · 8 km deep · 42 km away
19. 3.118 km E of Potter Valley, CaliforniaThu, Apr 21, 1:01 AM PST · 15869 days ago · 10 km deep · 42 km away
20. 1.95 km SSW of Cobb, CaliforniaWed, Apr 20, 9:57 PM PST · 15869 days ago · -1 km deep · 97 km away

From the USGS Earthquake Hazards Program and its partner networks, event nc1090978. Read Thu, Oct 1, 2026, 2:59 AM UTC.