M1.8 earthquake 8 km ENE of Blackhawk, California

Magnitude

1.8 (md), micro

Local time

Wed, Sep 23, 1981, 9:25 PM PDT

UTC

1981-09-24 04:25:13 UTC

Depth

14.1 km (8.7 mi), shallow

Epicenter

37.848° N, 121.818° W

Region

California

Tsunami flag

No

Status

Reviewed by a seismologist

Location uncertainty

About 0.2 km horizontally, 0.3 km in depth

Magnitude uncertainty

±0.17

Depth from

From location

Station coverage gap

121°

Stations used

38

• Blackhawk, CaliforniaPopulation 9,354. Forecast8 kmENE
• Brentwood, CaliforniaPopulation 58,968. Forecast14 kmSW
• Antioch, CaliforniaPopulation 110,542. Forecast17 kmS
• Los Angeles, CaliforniaPopulation 3,820,914. Forecast531 kmNW

After

1. 1.85 km E of Fremont, CaliforniaSat, Sep 26, 10:37 AM PDT · 16432 days ago · 9 km deep · 35 km away
2. 2.39 km ESE of East Foothills, CaliforniaSat, Sep 26, 10:41 PM PDT · 16432 days ago · 8 km deep · 56 km away
3. 2.49 km NE of Gilroy, CaliforniaSun, Sep 27, 12:57 AM PDT · 16432 days ago · 9 km deep · 92 km away
4. 2.93 km ESE of Brentwood, CaliforniaThu, Oct 1, 10:05 PM PDT · 16427 days ago · 9 km deep · 17 km away
5. 1.73 km SSW of Oakville, CaliforniaFri, Oct 2, 9:15 PM PDT · 16426 days ago · 6 km deep · 82 km away
6. 1.54 km SSE of Diablo Grande, CaliforniaSat, Oct 3, 4:17 AM PDT · 16425 days ago · 8 km deep · 73 km away
7. 1.89 km NE of Milpitas, CaliforniaSat, Oct 3, 8:29 PM PDT · 16425 days ago · 7 km deep · 39 km away
8. 2.322 km SE of Livermore, CaliforniaMon, Oct 5, 2:55 AM PDT · 16423 days ago · 7 km deep · 39 km away
9. 2.31 km NNE of Pacifica, CaliforniaMon, Oct 5, 9:02 PM PDT · 16423 days ago · 7 km deep · 63 km away
10. 1.86 km SE of Lexington Hills, CaliforniaTue, Oct 6, 12:22 AM PDT · 16423 days ago · 13 km deep · 80 km away
11. 1.81 km NNE of Pacifica, CaliforniaTue, Oct 6, 4:41 AM PDT · 16422 days ago · 7 km deep · 63 km away
12. 2.110 km SSW of Tracy, CaliforniaTue, Oct 6, 5:34 AM PDT · 16422 days ago · 9 km deep · 39 km away
13. 1.66 km SW of Gilroy, CaliforniaThu, Oct 8, 10:14 AM PDT · 16420 days ago · 5 km deep · 99 km away
14. 1.76 km NE of East Foothills, CaliforniaThu, Oct 8, 6:39 PM PDT · 16420 days ago · 8 km deep · 48 km away
15. 2.15 km NNE of San Leandro, CaliforniaFri, Oct 9, 12:24 AM PDT · 16420 days ago · 11 km deep · 29 km away
16. 1.715 km WNW of Davenport, CaliforniaFri, Oct 9, 6:54 AM PDT · 16419 days ago · 4 km deep · 96 km away
17. 1.84 km WSW of Kenwood, CaliforniaFri, Oct 9, 4:44 PM PDT · 16419 days ago · 8 km deep · 92 km away
18. 1.717 km N of Moskowite Corner, CaliforniaSun, Oct 11, 11:33 PM PDT · 16417 days ago · 8 km deep · 90 km away
19. 2.014 km N of Moskowite Corner, CaliforniaMon, Oct 12, 2:10 AM PDT · 16417 days ago · 0 km deep · 87 km away
20. 2.19 km ESE of East Foothills, CaliforniaMon, Oct 12, 5:44 PM PDT · 16416 days ago · 7 km deep · 56 km away
21. 2.010 km N of Pittsburg, CaliforniaThu, Oct 15, 1:05 AM PDT · 16414 days ago · 21 km deep · 31 km away
22. 2.03 km SSE of Brentwood, CaliforniaSat, Oct 17, 2:46 AM PDT · 16411 days ago · 2 km deep · 14 km away
23. 2.714 km E of Seven Trees, CaliforniaWed, Oct 21, 3:42 AM PDT · 16407 days ago · 7 km deep · 61 km away
24. 1.99 km NE of Gilroy, CaliforniaThu, Oct 22, 10:34 AM PDT · 16406 days ago · 8 km deep · 92 km away
25. 1.72 km NE of San Leandro, CaliforniaThu, Oct 22, 10:18 PM PDT · 16406 days ago · 3 km deep · 30 km away
26. 1.87 km SSW of Pescadero, CaliforniaFri, Oct 23, 2:56 AM PDT · 16405 days ago · 14 km deep · 90 km away
27. 1.715 km NE of Morgan Hill, CaliforniaFri, Oct 23, 8:20 AM PDT · 16405 days ago · 7 km deep · 72 km away
28. 2.310 km ESE of East Foothills, CaliforniaFri, Oct 23, 7:01 PM PDT · 16405 days ago · 8 km deep · 57 km away
29. 2.710 km ESE of East Foothills, CaliforniaFri, Oct 23, 8:03 PM PDT · 16405 days ago · 8 km deep · 57 km away
30. 1.63 km ENE of Grayson, CaliforniaFri, Oct 23, 10:43 PM PDT · 16405 days ago · -1 km deep · 66 km away
31. 2.015 km WNW of Davenport, CaliforniaSat, Oct 24, 4:49 AM PDT · 16404 days ago · 1 km deep · 98 km away
32. 2.28 km ENE of Gilroy, CaliforniaSat, Oct 24, 7:44 PM PDT · 16404 days ago · 8 km deep · 95 km away
33. 2.32 km S of Fairview, CaliforniaSun, Oct 25, 4:27 AM PST · 16403 days ago · 6 km deep · 29 km away
34. 1.712 km SE of Livermore, CaliforniaSun, Oct 25, 7:56 AM PST · 16403 days ago · 6 km deep · 31 km away
35. 2.87 km S of Sunol, CaliforniaSun, Oct 25, 3:55 PM PST · 16403 days ago · 9 km deep · 37 km away
36. 2.211 km ENE of Blackhawk, CaliforniaMon, Oct 26, 7:34 PM PST · 16402 days ago · 16 km deep · 3 km away
37. 2.38 km ESE of East Foothills, CaliforniaMon, Oct 26, 10:11 PM PST · 16402 days ago · 8 km deep · 55 km away
38. 1.85 km WNW of Broadmoor, CaliforniaTue, Oct 27, 4:31 PM PST · 16401 days ago · 7 km deep · 65 km away
39. 1.818 km N of Moskowite Corner, CaliforniaWed, Oct 28, 5:32 PM PST · 16400 days ago · 8 km deep · 91 km away
40. 2.02 km E of Ladera, CaliforniaWed, Oct 28, 6:30 PM PST · 16400 days ago · 4 km deep · 59 km away
41. 1.62 km SE of Ladera, CaliforniaWed, Oct 28, 10:33 PM PST · 16400 days ago · 2 km deep · 60 km away
42. 2.417 km N of Moskowite Corner, CaliforniaThu, Oct 29, 9:55 AM PST · 16399 days ago · 9 km deep · 91 km away
43. 2.518 km N of Moskowite Corner, CaliforniaThu, Oct 29, 10:13 AM PST · 16399 days ago · 8 km deep · 91 km away
44. 2.020 km ESE of East Foothills, CaliforniaSat, Oct 31, 10:05 AM PST · 16397 days ago · 6 km deep · 61 km away
45. 1.75 km SW of Gilroy, CaliforniaSat, Oct 31, 5:03 PM PST · 16397 days ago · 5 km deep · 99 km away
46. 1.93 km S of Fairview, CaliforniaSun, Nov 1, 6:38 AM PST · 16396 days ago · 4 km deep · 31 km away
47. 3.11 km ENE of Pittsburg, CaliforniaMon, Nov 2, 7:03 AM PST · 16395 days ago · 15 km deep · 21 km away
48. 2.33 km S of Fairview, CaliforniaMon, Nov 2, 7:43 AM PST · 16395 days ago · 4 km deep · 30 km away
49. 1.73 km S of Green Valley, CaliforniaMon, Nov 2, 4:43 PM PST · 16395 days ago · 9 km deep · 52 km away
50. 2.28 km ENE of Milpitas, CaliforniaWed, Nov 4, 6:56 AM PST · 16393 days ago · 7 km deep · 43 km away
51. 2.27 km E of East Foothills, CaliforniaFri, Nov 6, 10:25 AM PST · 16391 days ago · 7 km deep · 52 km away
52. 1.815 km S of Pescadero, CaliforniaFri, Nov 6, 2:49 PM PST · 16391 days ago · 5 km deep · 95 km away
53. 2.09 km NE of San Martin, CaliforniaTue, Nov 10, 6:08 AM PST · 16387 days ago · 8 km deep · 83 km away
54. 2.33 km SW of Antioch, CaliforniaWed, Nov 11, 10:57 AM PST · 16386 days ago · 18 km deep · 15 km away
55. 1.93 km SW of Antioch, CaliforniaWed, Nov 11, 11:05 AM PST · 16386 days ago · 19 km deep · 15 km away
56. 1.516 km SE of Livermore, CaliforniaFri, Nov 13, 6:09 AM PST · 16384 days ago · 9 km deep · 35 km away
57. 1.88 km ENE of Gilroy, CaliforniaSat, Nov 14, 9:02 PM PST · 16383 days ago · 4 km deep · 94 km away
58. 1.99 km ESE of Lexington Hills, CaliforniaMon, Nov 16, 4:27 AM PST · 16381 days ago · 11 km deep · 81 km away
59. 3.39 km ENE of Gilroy, CaliforniaMon, Nov 16, 11:47 AM PST · 16381 days ago · 9 km deep · 94 km away
60. 1.83 km SE of Pacifica, CaliforniaTue, Nov 17, 2:57 AM PST · 16380 days ago · 9 km deep · 63 km away

The first 60 of 67.

Before

1. 1.82 km NNE of Woodside, CaliforniaTue, Sep 22, 5:53 PM PDT · 16436 days ago · 5 km deep · 58 km away
2. 1.714 km NNW of Moskowite Corner, CaliforniaTue, Sep 22, 4:29 AM PDT · 16436 days ago · 0 km deep · 89 km away
3. 2.19 km ESE of East Foothills, CaliforniaSun, Sep 20, 9:46 PM PDT · 16438 days ago · 5 km deep · 56 km away
4. 1.521 km ENE of East Foothills, CaliforniaSun, Sep 20, 5:23 PM PDT · 16438 days ago · 6 km deep · 46 km away
5. 1.714 km E of Seven Trees, CaliforniaFri, Sep 18, 3:26 AM PDT · 16440 days ago · 4 km deep · 63 km away
6. 1.75 km WNW of Broadmoor, CaliforniaThu, Sep 17, 1:29 AM PDT · 16442 days ago · 4 km deep · 65 km away
7. 1.615 km N of Morgan Hill, CaliforniaWed, Sep 16, 2:46 AM PDT · 16442 days ago · 6 km deep · 67 km away
8. 1.615 km N of Morgan Hill, CaliforniaWed, Sep 16, 2:30 AM PDT · 16442 days ago · 6 km deep · 66 km away
9. 2.011 km SSW of Loyola, CaliforniaMon, Sep 14, 1:49 PM PDT · 16444 days ago · 9 km deep · 72 km away
10. 2.67 km W of Gilroy, CaliforniaSun, Sep 13, 6:16 AM PDT · 16445 days ago · 4 km deep · 96 km away
11. 3.09 km NE of San Martin, CaliforniaSat, Sep 12, 8:49 AM PDT · 16446 days ago · 8 km deep · 81 km away
12. 1.61 km WSW of Belmont, CaliforniaFri, Sep 11, 10:06 AM PDT · 16447 days ago · 3 km deep · 56 km away
13. 2.19 km ENE of Morgan Hill, CaliforniaTue, Sep 8, 8:10 AM PDT · 16450 days ago · 6 km deep · 80 km away
14. 1.611 km SSW of Loyola, CaliforniaSun, Sep 6, 11:23 AM PDT · 16452 days ago · 10 km deep · 72 km away
15. 1.89 km E of San Martin, CaliforniaSun, Sep 6, 10:40 AM PDT · 16452 days ago · 9 km deep · 90 km away
16. 1.611 km ENE of Milpitas, CaliforniaThu, Sep 3, 8:57 AM PDT · 16455 days ago · 4 km deep · 41 km away
17. 1.518 km ESE of East Foothills, CaliforniaThu, Sep 3, 3:15 AM PDT · 16455 days ago · 1 km deep · 62 km away
18. 1.65 km E of Fremont, CaliforniaWed, Sep 2, 6:39 AM PDT · 16456 days ago · 10 km deep · 34 km away
19. 1.74 km N of Milpitas, CaliforniaWed, Sep 2, 4:48 AM PDT · 16456 days ago · 3 km deep · 42 km away
20. 2.06 km S of Sunol, CaliforniaTue, Sep 1, 10:57 PM PDT · 16457 days ago · 9 km deep · 36 km away

From the USGS Earthquake Hazards Program and its partner networks, event nc1067870. Read Tue, Sep 22, 2026, 8:45 PM UTC.