California earthquakes

M1.8 earthquake 9 km SSW of Ridgemark, California

A magnitude 1.8 earthquake struck 9 km SSW of Ridgemark, California on Fri, Aug 1, 1986, 11:21 AM PDT (18:21 UTC), 6 km (4 mi) below the surface.

A larger quake followed: M4.0 16 km E of Seven Trees, 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.

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The earthquake

Magnitude
1.8 (md), micro
Local time
UTC
1986-08-01 18:21:11 UTC
Depth
6.4 km (4.0 mi), shallow
Epicenter
36.737° N, 121.410° 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, 0.4 km in depth
Magnitude uncertainty
±0.17
Depth from
From location
Station coverage gap
36°
Stations used
31

Nearest places

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

Nearby

Within 100 km, magnitude 1.5 and up: 168 in the 60 days after this one and 158 in the 30 days before it.

After

  1. 2.69 km SSW of Ridgemark, California · 14668 days ago · 6 km deep · 0 km away
  2. 1.96 km S of Big Sur, California · 14667 days ago · 15 km deep · 68 km away
  3. 2.513 km ENE of East Foothills, California · 14667 days ago · 8 km deep · 81 km away
  4. 3.422 km NNE of Soledad, California · 14667 days ago · 6 km deep · 24 km away
  5. 1.622 km NNE of Soledad, California · 14667 days ago · 6 km deep · 24 km away
  6. 2.022 km NNE of Soledad, California · 14666 days ago · 5 km deep · 24 km away
  7. 2.322 km NNE of Soledad, California · 14666 days ago · 6 km deep · 25 km away
  8. 1.66 km WSW of Gilroy, California · 14666 days ago · 4 km deep · 34 km away
  9. 1.919 km NE of East Foothills, California · 14666 days ago · 6 km deep · 90 km away
  10. 2.422 km NNE of Soledad, California · 14666 days ago · 6 km deep · 24 km away
  11. 2.124 km NE of Greenfield, California · 14666 days ago · 0 km deep · 48 km away
  12. 1.524 km ENE of Greenfield, California · 14666 days ago · 4 km deep · 48 km away
  13. 3.46 km NE of East Foothills, California · 14666 days ago · 9 km deep · 83 km away
  14. 2.56 km NE of East Foothills, California · 14666 days ago · 9 km deep · 83 km away
  15. 2.615 km SSE of Tres Pinos, California · 14666 days ago · 7 km deep · 15 km away
  16. 2.3Central California · 14666 days ago · 7 km deep · 15 km away
  17. 1.518 km NE of East Foothills, California · 14665 days ago · 6 km deep · 89 km away
  18. 1.75 km SE of Tres Pinos, California · 14665 days ago · 8 km deep · 12 km away
  19. 2.17 km S of Davenport, California · 14665 days ago · 6 km deep · 73 km away
  20. 1.818 km S of Big Sur, California · 14664 days ago · 16 km deep · 79 km away
  21. 2.615 km SSE of Tres Pinos, California · 14664 days ago · 7 km deep · 15 km away
  22. 2.46 km NNE of Tres Pinos, California · 14664 days ago · 7 km deep · 15 km away
  23. 2.622 km NNE of Soledad, California · 14664 days ago · 7 km deep · 25 km away
  24. 1.518 km NE of East Foothills, California · 14664 days ago · 6 km deep · 89 km away
  25. 1.87 km NE of Ridgemark, California · 14664 days ago · 4 km deep · 16 km away
  26. 2.35 km SE of Tres Pinos, California · 14663 days ago · 8 km deep · 13 km away
  27. 1.75 km SE of Tres Pinos, California · 14663 days ago · 8 km deep · 13 km away
  28. 2.923 km NE of King City, California · 14663 days ago · 4 km deep · 62 km away
  29. 1.58 km ESE of East Foothills, California · 14663 days ago · 6 km deep · 74 km away
  30. 2.68 km ESE of East Foothills, California · 14663 days ago · 6 km deep · 75 km away
  31. 1.524 km ENE of Soledad, California · 14663 days ago · 4 km deep · 40 km away
  32. 3.215 km SSE of Tres Pinos, California · 14663 days ago · 6 km deep · 15 km away
  33. 1.616 km SSE of Tres Pinos, California · 14663 days ago · 6 km deep · 15 km away
  34. 1.815 km SSE of Tres Pinos, California · 14663 days ago · 6 km deep · 15 km away
  35. 1.615 km SSE of Tres Pinos, California · 14663 days ago · 6 km deep · 15 km away
  36. 1.825 km NE of Greenfield, California · 14663 days ago · 0 km deep · 47 km away
  37. 2.411 km NNE of East Foothills, California · 14663 days ago · 3 km deep · 86 km away
  38. 2.66 km NE of Ridgemark, California · 14662 days ago · 5 km deep · 16 km away
  39. 1.65 km NE of Tres Pinos, California · 14662 days ago · 9 km deep · 15 km away
  40. 1.95 km SW of Gonzales, California · 14662 days ago · 10 km deep · 30 km away
  41. 2.722 km NNE of Soledad, California · 14662 days ago · 7 km deep · 23 km away
  42. 1.64 km SW of Gonzales, California · 14661 days ago · 10 km deep · 30 km away
  43. 1.624 km ENE of Greenfield, California · 14661 days ago · 2 km deep · 48 km away
  44. 1.65 km SE of Tres Pinos, California · 14661 days ago · 8 km deep · 13 km away
  45. 1.95 km WSW of Gilroy, California · 14661 days ago · 4 km deep · 34 km away
  46. 1.815 km SSE of Tres Pinos, California · 14660 days ago · 7 km deep · 14 km away
  47. 1.919 km SSE of Livermore, California · 14660 days ago · 7 km deep · 90 km away
  48. 2.46 km NE of Ridgemark, California · 14660 days ago · 4 km deep · 16 km away
  49. 2.03 km NE of Tres Pinos, California · 14660 days ago · 8 km deep · 14 km away
  50. 1.75 km SE of Tres Pinos, California · 14659 days ago · 8 km deep · 13 km away
  51. 1.815 km SSE of Livermore, California · 14659 days ago · 4 km deep · 95 km away
  52. 2.16 km SSE of Tres Pinos, California · 14659 days ago · 12 km deep · 9 km away
  53. 1.69 km NNE of Milpitas, California · 14659 days ago · 8 km deep · 93 km away
  54. 2.021 km NE of Soledad, California · 14659 days ago · 7 km deep · 30 km away
  55. 1.5Northern California · 14659 days ago · 6 km deep · 89 km away
  56. 1.712 km ENE of East Foothills, California · 14658 days ago · 7 km deep · 80 km away
  57. 1.518 km NE of East Foothills, California · 14658 days ago · 7 km deep · 89 km away
  58. 1.614 km SE of Livermore, California · 14658 days ago · 3 km deep · 96 km away
  59. 1.89 km ESE of East Foothills, California · 14657 days ago · 7 km deep · 73 km away
  60. 1.79 km ESE of East Foothills, California · 14657 days ago · 7 km deep · 73 km away

The first 60 of 168.

Before

  1. 1.721 km NE of Soledad, California · 14668 days ago · 7 km deep · 31 km away
  2. 1.712 km NE of East Foothills, California · 14669 days ago · 8 km deep · 86 km away
  3. 1.619 km SSE of Livermore, California · 14669 days ago · 6 km deep · 91 km away
  4. 1.717 km NE of East Foothills, California · 14669 days ago · 6 km deep · 89 km away
  5. 1.98 km W of Diablo Grande, California · 14669 days ago · 3 km deep · 72 km away
  6. 1.718 km SSE of Livermore, California · 14669 days ago · 8 km deep · 91 km away
  7. 2.24 km N of East Foothills, California · 14669 days ago · 2 km deep · 84 km away
  8. 1.617 km SSE of Tres Pinos, California · 14669 days ago · 6 km deep · 17 km away
  9. 1.618 km NE of East Foothills, California · 14670 days ago · 6 km deep · 90 km away
  10. 2.018 km NE of East Foothills, California · 14670 days ago · 6 km deep · 89 km away
  11. 1.611 km S of Tres Pinos, California · 14670 days ago · 4 km deep · 10 km away
  12. 2.614 km ENE of Greenfield, California · 14670 days ago · 17 km deep · 50 km away
  13. 2.22 km SSE of Big Sur, California · 14670 days ago · 9 km deep · 64 km away
  14. 2.16 km NNE of Interlaken, California · 14670 days ago · 8 km deep · 40 km away
  15. 1.614 km N of Morgan Hill, California · 14671 days ago · 5 km deep · 61 km away
  16. 2.424 km NE of Greenfield, California · 14671 days ago · 5 km deep · 48 km away
  17. 2.211 km NNE of Morgan Hill, California · 14672 days ago · 5 km deep · 59 km away
  18. 1.712 km S of Tres Pinos, California · 14672 days ago · 3 km deep · 11 km away
  19. 1.624 km SE of Tres Pinos, California · 14672 days ago · 5 km deep · 26 km away
  20. 2.218 km NE of East Foothills, California · 14672 days ago · 6 km deep · 89 km away

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Sources

From the USGS Earthquake Hazards Program and its partner networks, event nc86645. Read Mon, Sep 28, 2026, 9:07 PM UTC.