M2.1 earthquake 6 km NNE of Ridgemark, California

Magnitude

2.1 (Md, duration), micro

Magnitude from

Northern California Seismic System

Local time

Mon, Mar 27, 1978, 11:33 PM PST

UTC

1978-03-28 07:33:38 UTC

Depth

6.1 km (3.8 mi), shallow

Epicenter

36.861° N, 121.328° W

Region

California

Tsunami flag

No

Status

Reviewed by a seismologist

Location uncertainty

About 0.2 km horizontally, 0.4 km in depth

Magnitude uncertainty

±0.15

Depth from

From location

Station coverage gap

74°

Stations used

58

• Ridgemark, CaliforniaPopulation 3,016. Forecast6 kmNNE
• Hollister, CaliforniaPopulation 37,462. Forecast7 kmE
• Salinas, CaliforniaPopulation 157,380. Forecast36 kmNE
• Los Angeles, CaliforniaPopulation 3,820,914. Forecast419 kmNW

After

1. 3.04 km SE of Aromas, CaliforniaTue, Mar 28, 1:51 AM PST · 17722 days ago · 8 km deep · 24 km away
2. 1.65 km WNW of San Juan Bautista, CaliforniaTue, Mar 28, 1:55 AM PST · 17722 days ago · 7 km deep · 24 km away
3. 2.84 km SE of Aromas, CaliforniaTue, Mar 28, 2:02 AM PST · 17722 days ago · 8 km deep · 24 km away
4. 2.75 km WNW of San Juan Bautista, CaliforniaTue, Mar 28, 9:22 AM PST · 17722 days ago · 8 km deep · 24 km away
5. 2.01 km WNW of Cambrian Park, CaliforniaWed, Mar 29, 1:40 AM PST · 17721 days ago · 8 km deep · 71 km away
6. 2.01 km WNW of Cambrian Park, CaliforniaWed, Mar 29, 8:27 AM PST · 17721 days ago · 8 km deep · 71 km away
7. 1.923 km ENE of Soledad, CaliforniaWed, Mar 29, 8:39 AM PST · 17721 days ago · 3 km deep · 44 km away
8. 2.126 km ENE of Soledad, CaliforniaThu, Mar 30, 8:51 PM PST · 17720 days ago · 9 km deep · 41 km away
9. 1.56 km E of Hollister, CaliforniaThu, Mar 30, 10:05 PM PST · 17720 days ago · 5 km deep · 0 km away
10. 1.624 km NE of Greenfield, CaliforniaThu, Mar 30, 11:16 PM PST · 17719 days ago · 4 km deep · 48 km away
11. 2.1Central CaliforniaFri, Mar 31, 6:36 PM PST · 17719 days ago · 4 km deep · 21 km away
12. 2.112 km SSE of Tres Pinos, CaliforniaSat, Apr 1, 1:44 AM PST · 17718 days ago · 5 km deep · 20 km away
13. 2.137 km W of Lockwood, CaliforniaSat, Apr 1, 2:30 AM PST · 17718 days ago · 17 km deep · 97 km away
14. 2.124 km NE of Greenfield, CaliforniaSat, Apr 1, 5:23 PM PST · 17718 days ago · 5 km deep · 51 km away
15. 1.610 km NNE of San Juan Bautista, CaliforniaSun, Apr 2, 1:06 PM PST · 17717 days ago · 0 km deep · 15 km away
16. 2.426 km NE of Soledad, CaliforniaSun, Apr 2, 7:30 PM PST · 17717 days ago · 9 km deep · 36 km away
17. 1.8Northern CaliforniaMon, Apr 3, 5:35 AM PST · 17716 days ago · 5 km deep · 55 km away
18. 2.022 km NE of Soledad, CaliforniaTue, Apr 4, 12:28 PM PST · 17715 days ago · 2 km deep · 40 km away
19. 1.69 km ENE of Gilroy, CaliforniaThu, Apr 6, 11:13 PM PST · 17712 days ago · 8 km deep · 24 km away
20. 2.79 km SSE of San Juan Bautista, CaliforniaFri, Apr 7, 3:56 AM PST · 17712 days ago · 6 km deep · 17 km away
21. 2.86 km ESE of Sunol, CaliforniaFri, Apr 7, 4:13 PM PST · 17712 days ago · 11 km deep · 90 km away
22. 2.210 km SE of San Juan Bautista, CaliforniaFri, Apr 7, 10:27 PM PST · 17712 days ago · 6 km deep · 16 km away
23. 2.119 km W of Volta, CaliforniaSat, Apr 8, 8:02 AM PST · 17711 days ago · 0 km deep · 32 km away
24. 2.29 km NW of Hollister, CaliforniaSat, Apr 8, 8:25 AM PST · 17711 days ago · 6 km deep · 14 km away
25. 2.015 km E of Seven Trees, CaliforniaSun, Apr 9, 10:07 PM PST · 17710 days ago · 3 km deep · 56 km away
26. 1.65 km E of Fremont, CaliforniaMon, Apr 10, 7:41 AM PST · 17709 days ago · 7 km deep · 92 km away
27. 2.35 km NNE of Tres Pinos, CaliforniaWed, Apr 12, 6:06 PM PST · 17707 days ago · 4 km deep · 4 km away
28. 1.623 km NE of San Lucas, CaliforniaWed, Apr 12, 7:36 PM PST · 17707 days ago · 6 km deep · 81 km away
29. 1.917 km SSE of Tres Pinos, CaliforniaWed, Apr 12, 11:32 PM PST · 17706 days ago · 4 km deep · 25 km away
30. 1.821 km SSE of Tres Pinos, CaliforniaThu, Apr 13, 12:12 AM PST · 17706 days ago · 5 km deep · 29 km away
31. 2.221 km SSE of Tres Pinos, CaliforniaThu, Apr 13, 5:08 AM PST · 17706 days ago · 5 km deep · 29 km away
32. 1.717 km E of East Foothills, CaliforniaThu, Apr 13, 2:08 PM PST · 17706 days ago · 6 km deep · 60 km away
33. 3.19 km SSE of San Juan Bautista, CaliforniaFri, Apr 14, 7:00 AM PST · 17705 days ago · 8 km deep · 17 km away
34. 2.322 km ENE of San Lucas, CaliforniaSun, Apr 16, 9:20 PM PST · 17703 days ago · 8 km deep · 86 km away
35. 1.722 km ENE of San Lucas, CaliforniaSun, Apr 16, 10:11 PM PST · 17703 days ago · 7 km deep · 86 km away
36. 2.623 km ENE of San Lucas, CaliforniaSun, Apr 16, 11:30 PM PST · 17702 days ago · 8 km deep · 86 km away
37. 1.910 km SE of San Juan Bautista, CaliforniaMon, Apr 17, 6:11 AM PST · 17702 days ago · 6 km deep · 16 km away
38. 2.34 km S of San Juan Bautista, CaliforniaMon, Apr 17, 6:33 AM PST · 17702 days ago · 7 km deep · 19 km away
39. 2.722 km NNE of Soledad, CaliforniaMon, Apr 17, 5:24 PM PST · 17702 days ago · 6 km deep · 31 km away
40. 2.121 km NNE of Soledad, CaliforniaTue, Apr 18, 10:04 AM PST · 17701 days ago · 8 km deep · 32 km away
41. 2.05 km ENE of Hollister, CaliforniaWed, Apr 19, 2:44 PM PST · 17700 days ago · 6 km deep · 1 km away
42. 1.813 km N of Morgan Hill, CaliforniaWed, Apr 19, 8:59 PM PST · 17700 days ago · 7 km deep · 51 km away
43. 1.98 km NW of Hollister, CaliforniaFri, Apr 21, 7:12 PM PST · 17698 days ago · 7 km deep · 13 km away
44. 1.939 km W of Three Rocks, CaliforniaSun, Apr 23, 12:03 AM PST · 17696 days ago · 6 km deep · 58 km away
45. 2.021 km NE of Soledad, CaliforniaSun, Apr 23, 5:55 AM PST · 17696 days ago · 6 km deep · 37 km away
46. 2.934 km SE of Big Sur, CaliforniaSun, Apr 23, 7:09 AM PST · 17696 days ago · 17 km deep · 96 km away
47. 2.122 km ENE of San Ardo, CaliforniaWed, Apr 26, 2:17 PM PST · 17693 days ago · 5 km deep · 100 km away
48. 1.624 km NE of Greenfield, CaliforniaFri, Apr 28, 9:38 PM PST · 17691 days ago · 5 km deep · 50 km away
49. 1.624 km NE of Greenfield, CaliforniaSun, Apr 30, 3:56 AM PDT · 17689 days ago · 5 km deep · 52 km away
50. 2.323 km NE of King City, CaliforniaMon, May 1, 5:19 AM PDT · 17688 days ago · 7 km deep · 62 km away
51. 1.516 km SSE of Tres Pinos, CaliforniaTue, May 2, 10:22 PM PDT · 17687 days ago · 4 km deep · 24 km away
52. 2.613 km ESE of Tres Pinos, CaliforniaWed, May 3, 6:10 PM PDT · 17686 days ago · 10 km deep · 19 km away
53. 2.911 km NNE of Morgan Hill, CaliforniaWed, May 3, 6:18 PM PDT · 17686 days ago · 4 km deep · 49 km away
54. 1.81 km NNE of Tres Pinos, CaliforniaThu, May 4, 12:26 AM PDT · 17685 days ago · 8 km deep · 7 km away
55. 1.523 km ENE of Soledad, CaliforniaThu, May 4, 4:54 AM PDT · 17685 days ago · 3 km deep · 46 km away
56. 1.724 km ENE of San Lucas, CaliforniaThu, May 4, 8:52 AM PDT · 17685 days ago · 5 km deep · 85 km away
57. 2.218 km SSE of Tres Pinos, CaliforniaFri, May 5, 1:23 AM PDT · 17684 days ago · 10 km deep · 26 km away
58. 2.619 km SSW of Volta, CaliforniaFri, May 5, 5:07 AM PDT · 17684 days ago · 4 km deep · 29 km away
59. 1.731 km W of Three Rocks, CaliforniaFri, May 5, 4:56 PM PDT · 17684 days ago · 8 km deep · 65 km away
60. 2.55 km ESE of East Foothills, CaliforniaSun, May 7, 11:55 PM PDT · 17682 days ago · 0 km deep · 68 km away

The first 60 of 149.

Before

1. 1.68 km SE of Sunol, CaliforniaMon, Mar 27, 11:28 PM PST · 17722 days ago · 3 km deep · 87 km away
2. 2.54 km SE of Aromas, CaliforniaMon, Mar 27, 10:30 AM PST · 17723 days ago · 8 km deep · 24 km away
3. 1.618 km E of East Foothills, CaliforniaMon, Mar 27, 9:25 AM PST · 17723 days ago · 5 km deep · 60 km away
4. 1.816 km E of Seven Trees, CaliforniaMon, Mar 27, 4:59 AM PST · 17723 days ago · 6 km deep · 56 km away
5. 2.85 km SW of Gilroy, CaliforniaFri, Mar 24, 11:42 AM PST · 17726 days ago · 4 km deep · 28 km away
6. 1.924 km NE of Greenfield, CaliforniaThu, Mar 23, 11:19 AM PST · 17727 days ago · 5 km deep · 52 km away
7. 1.822 km NNE of Soledad, CaliforniaThu, Mar 23, 10:37 AM PST · 17727 days ago · 5 km deep · 32 km away
8. 1.92 km NW of Diablo Grande, CaliforniaThu, Mar 23, 6:20 AM PST · 17727 days ago · 0 km deep · 62 km away
9. 2.06 km SE of Tres Pinos, CaliforniaWed, Mar 22, 9:20 AM PST · 17728 days ago · 10 km deep · 13 km away
10. 1.724 km NE of Greenfield, CaliforniaSun, Mar 19, 12:18 PM PST · 17731 days ago · 5 km deep · 51 km away
11. 1.83 km SW of Loyola, CaliforniaSun, Mar 19, 1:03 AM PST · 17731 days ago · 5 km deep · 87 km away
12. 2.69 km SE of Sunol, CaliforniaFri, Mar 17, 11:44 AM PST · 17733 days ago · 2 km deep · 86 km away
13. 1.925 km ENE of Greenfield, CaliforniaThu, Mar 16, 1:55 PM PST · 17734 days ago · 6 km deep · 56 km away
14. 2.16 km NE of Ridgemark, CaliforniaThu, Mar 16, 11:54 AM PST · 17734 days ago · 6 km deep · 1 km away
15. 1.724 km NE of Greenfield, CaliforniaWed, Mar 15, 1:11 AM PST · 17735 days ago · 3 km deep · 51 km away
16. 2.824 km NE of Greenfield, CaliforniaWed, Mar 15, 1:09 AM PST · 17735 days ago · 3 km deep · 50 km away
17. 2.321 km NW of Diablo Grande, CaliforniaTue, Mar 14, 11:17 AM PST · 17736 days ago · 4 km deep · 74 km away
18. 2.115 km E of Seven Trees, CaliforniaMon, Mar 13, 8:41 AM PST · 17737 days ago · 6 km deep · 56 km away
19. 1.724 km NE of Greenfield, CaliforniaMon, Mar 13, 7:33 AM PST · 17737 days ago · 5 km deep · 51 km away
20. 2.624 km NE of Greenfield, CaliforniaSun, Mar 12, 7:42 PM PST · 17738 days ago · 2 km deep · 49 km away

From the USGS Earthquake Hazards Program and its partner networks, event nc1039585. Read Sun, Oct 4, 2026, 6:28 PM UTC.