California earthquakes

M2.9 earthquake 4 km SSW of Ridgemark, CA

A magnitude 2.9 earthquake struck 4 km SSW of Ridgemark, CA on Sat, Mar 28, 1981, 12:28 PM PST (20:28 UTC), 3 km (2 mi) below the surface.

A larger quake followed: M3.0 8 km SSW of Tres Pinos, California. This one was a foreshock.

Ridgemark forecastMore in California

Map

Where this earthquake was located, with the others nearby. Select one for its page.

Open the live map with earthquakes

The earthquake

Magnitude
2.9 (md), micro
Local time
UTC
1981-03-28 20:28:36 UTC
Depth
2.5 km (1.6 mi), shallow
Epicenter
36.780° N, 121.385° W
Tsunami flag
No
Status
Reviewed by a seismologist

Did you feel it?

No one has reported feeling this quake to the USGS.

How well it is located

Reviewed by a seismologist.

Location uncertainty
About 0.2 km horizontally, 0.6 km in depth
Magnitude uncertainty
±0.12
Depth from
From location
Station coverage gap
42°
Stations used
51

Nearest places

Distance and direction from each place to the epicenter, with its forecast.

Nearby

Within 100 km, magnitude 1.5 and up: 139 in the 60 days after this one and 34 in the 30 days before it.

After

  1. 1.822 km NE of San Ardo, California · 16614 days ago · 3 km deep · 87 km away
  2. 1.6Central California · 16613 days ago · 4 km deep · 72 km away
  3. 2.224 km ENE of Greenfield, California · 16612 days ago · 7 km deep · 54 km away
  4. 1.525 km NE of Greenfield, California · 16611 days ago · 6 km deep · 48 km away
  5. 2.112 km NNW of Hollister, California · 16611 days ago · 4 km deep · 20 km away
  6. 1.724 km NE of Greenfield, California · 16611 days ago · 6 km deep · 45 km away
  7. 1.70 km WNW of Hollister, California · 16611 days ago · 8 km deep · 9 km away
  8. 2.124 km NE of Greenfield, California · 16610 days ago · 6 km deep · 45 km away
  9. 2.07 km SSW of Tres Pinos, California · 16610 days ago · 3 km deep · 6 km away
  10. 1.63 km WSW of Hollister, California · 16609 days ago · 7 km deep · 9 km away
  11. 1.68 km NE of San Martin, California · 16609 days ago · 6 km deep · 41 km away
  12. 1.96 km S of Sunol, California · 16609 days ago · 9 km deep · 95 km away
  13. 2.110 km SSE of San Juan Bautista, California · 16609 days ago · 7 km deep · 8 km away
  14. 2.02 km WSW of San Juan Bautista, California · 16609 days ago · 7 km deep · 17 km away
  15. 1.65 km SSE of San Juan Bautista, California · 16608 days ago · 6 km deep · 12 km away
  16. 1.62 km NW of Bonny Doon, California · 16608 days ago · 12 km deep · 76 km away
  17. 2.123 km ENE of San Lucas, California · 16607 days ago · 6 km deep · 81 km away
  18. 1.616 km SSE of Livermore, California · 16607 days ago · -1 km deep · 90 km away
  19. 1.59 km NE of Gilroy, California · 16606 days ago · 8 km deep · 33 km away
  20. 1.923 km NNE of San Lucas, California · 16606 days ago · 9 km deep · 69 km away
  21. 1.624 km NNE of San Lucas, California · 16606 days ago · 9 km deep · 69 km away
  22. 1.816 km SSE of Tres Pinos, California · 16606 days ago · 4 km deep · 18 km away
  23. 1.74 km W of Westley, California · 16605 days ago · 8 km deep · 86 km away
  24. 1.58 km E of East Foothills, California · 16605 days ago · 8 km deep · 72 km away
  25. 1.53 km WSW of Campbell, California · 16605 days ago · 4 km deep · 77 km away
  26. 1.812 km S of Tres Pinos, California · 16604 days ago · 3 km deep · 13 km away
  27. 1.88 km SSW of Tres Pinos, California · 16604 days ago · 3 km deep · 7 km away
  28. 2.22 km NE of Ridgemark, California · 16602 days ago · 7 km deep · 6 km away
  29. 1.89 km NNW of Hollister, California · 16602 days ago · 0 km deep · 18 km away
  30. 1.625 km SE of Big Sur, California · 16601 days ago · 6 km deep · 74 km away
  31. 1.725 km SE of Big Sur, California · 16601 days ago · 4 km deep · 75 km away
  32. 2.025 km SE of Big Sur, California · 16601 days ago · 5 km deep · 76 km away
  33. 2.025 km SE of Big Sur, California · 16601 days ago · 10 km deep · 76 km away
  34. 1.925 km SE of Big Sur, California · 16601 days ago · 5 km deep · 76 km away
  35. 3.08 km SSW of Tres Pinos, California · 16600 days ago · 3 km deep · 7 km away
  36. 1.814 km E of Seven Trees, California · 16600 days ago · 1 km deep · 63 km away
  37. 2.124 km ENE of Soledad, California · 16599 days ago · 8 km deep · 38 km away
  38. 1.725 km ENE of Soledad, California · 16599 days ago · 8 km deep · 38 km away
  39. 1.610 km E of Gilroy, California · 16597 days ago · 8 km deep · 25 km away
  40. 1.65 km ENE of San Martin, California · 16597 days ago · 3 km deep · 38 km away
  41. 1.822 km SE of Livermore, California · 16597 days ago · 2 km deep · 85 km away
  42. 2.73 km W of San Juan Bautista, California · 16596 days ago · 6 km deep · 19 km away
  43. 2.83 km W of San Juan Bautista, California · 16596 days ago · 7 km deep · 19 km away
  44. 2.23 km W of San Juan Bautista, California · 16596 days ago · 6 km deep · 19 km away
  45. 1.77 km SSW of Tres Pinos, California · 16595 days ago · 3 km deep · 6 km away
  46. 1.713 km N of Hollister, California · 16594 days ago · 7 km deep · 21 km away
  47. 1.624 km ENE of Greenfield, California · 16594 days ago · 6 km deep · 50 km away
  48. 1.524 km ENE of Greenfield, California · 16594 days ago · 4 km deep · 50 km away
  49. 1.623 km ENE of King City, California · 16593 days ago · 9 km deep · 67 km away
  50. 1.52 km SSE of Tres Pinos, California · 16592 days ago · 6 km deep · 7 km away
  51. 1.824 km NE of Greenfield, California · 16592 days ago · 5 km deep · 47 km away
  52. 1.724 km NE of Greenfield, California · 16590 days ago · 5 km deep · 44 km away
  53. 1.94 km ESE of Interlaken, California · 16590 days ago · 10 km deep · 32 km away
  54. 1.523 km ENE of San Ardo, California · 16589 days ago · 7 km deep · 98 km away
  55. 1.97 km SE of Sunol, California · 16589 days ago · 5 km deep · 94 km away
  56. 1.82 km ESE of San Ardo, California · 16589 days ago · 11 km deep · 97 km away
  57. 2.426 km NE of King City, California · 16587 days ago · 6 km deep · 59 km away
  58. 1.626 km NE of King City, California · 16587 days ago · 4 km deep · 59 km away
  59. 1.730 km NE of San Lucas, California · 16586 days ago · 9 km deep · 74 km away
  60. 1.67 km NNE of East Foothills, California · 16586 days ago · 11 km deep · 81 km away

The first 60 of 139.

Before

  1. 1.515 km SSE of Livermore, California · 16614 days ago · 2 km deep · 91 km away
  2. 1.710 km E of San Martin, California · 16614 days ago · 9 km deep · 35 km away
  3. 1.921 km NE of Soledad, California · 16615 days ago · 6 km deep · 35 km away
  4. 2.42 km SSW of Hollister, California · 16615 days ago · 9 km deep · 6 km away
  5. 2.824 km NE of Greenfield, California · 16615 days ago · 6 km deep · 46 km away
  6. 1.732 km NE of San Lucas, California · 16615 days ago · 8 km deep · 76 km away
  7. 1.89 km NNE of San Juan Bautista, California · 16616 days ago · 4 km deep · 19 km away
  8. 1.614 km SSE of Livermore, California · 16616 days ago · 2 km deep · 91 km away
  9. 2.09 km S of Tres Pinos, California · 16616 days ago · 3 km deep · 9 km away
  10. 1.524 km NNE of King City, California · 16616 days ago · 7 km deep · 55 km away
  11. 1.57 km SSW of Tres Pinos, California · 16616 days ago · 4 km deep · 6 km away
  12. 1.713 km N of Morgan Hill, California · 16617 days ago · 6 km deep · 57 km away
  13. 2.08 km SSW of Tres Pinos, California · 16617 days ago · 4 km deep · 7 km away
  14. 3.114 km SSE of Livermore, California · 16617 days ago · 2 km deep · 91 km away
  15. 1.58 km SSW of Tres Pinos, California · 16617 days ago · 4 km deep · 7 km away
  16. 2.07 km SSW of Tres Pinos, California · 16617 days ago · 3 km deep · 6 km away
  17. 2.08 km SSW of Tres Pinos, California · 16617 days ago · 4 km deep · 7 km away
  18. 1.58 km SSW of Tres Pinos, California · 16617 days ago · 4 km deep · 7 km away
  19. 1.69 km NE of San Martin, California · 16618 days ago · 7 km deep · 43 km away
  20. 2.025 km NE of Soledad, California · 16618 days ago · 10 km deep · 33 km away

Earthquakes todayCalifornia earthquakesLive radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event nc1061830. Read Tue, Sep 22, 2026, 4:20 PM UTC.