California earthquakes

M1.9 earthquake 2 km ENE of Ridgemark, California

A magnitude 1.9 earthquake struck 2 km ENE of Ridgemark, California on Mon, Sep 4, 1978, 3:35 AM PDT (10:35 UTC), 6 km (4 mi) below the surface.

A larger quake followed: M3.9 10 km S 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.

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The earthquake

Magnitude
1.9 (Md, duration), micro
Magnitude from
Northern California Seismic System
Local time
UTC
1978-09-04 10:35:22 UTC
Depth
6.1 km (3.8 mi), shallow
Epicenter
36.824° N, 121.343° 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
±0.15
Depth from
From location
Station coverage gap
100°
Stations used
42

Nearest places

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

Nearby

Within 100 km, magnitude 1.5 and up: 157 in the 60 days after this one and 82 in the 30 days before it.

After

  1. 1.621 km NE of Soledad, California · 17559 days ago · 0 km deep · 30 km away
  2. 2.522 km ENE of San Ardo, California · 17559 days ago · 6 km deep · 97 km away
  3. 2.222 km ENE of San Lucas, California · 17559 days ago · 9 km deep · 81 km away
  4. 1.79 km ESE of Gilroy, California · 17558 days ago · 4 km deep · 20 km away
  5. 2.66 km ENE of Seven Trees, California · 17558 days ago · 5 km deep · 67 km away
  6. 1.612 km SW of Soledad, California · 17558 days ago · 11 km deep · 54 km away
  7. 2.125 km NNE of King City, California · 17557 days ago · 1 km deep · 57 km away
  8. 2.59 km SSE of Tres Pinos, California · 17556 days ago · 5 km deep · 14 km away
  9. 1.86 km NE of Ridgemark, California · 17556 days ago · 5 km deep · 4 km away
  10. 1.623 km NE of King City, California · 17555 days ago · 2 km deep · 65 km away
  11. 1.81 km SE of East Foothills, California · 17555 days ago · 5 km deep · 73 km away
  12. 1.63 km NE of Tres Pinos, California · 17555 days ago · 8 km deep · 4 km away
  13. 2.35 km ENE of Aromas, California · 17554 days ago · 8 km deep · 24 km away
  14. 2.310 km S of Tres Pinos, California · 17553 days ago · 3 km deep · 14 km away
  15. 3.410 km S of Tres Pinos, California · 17553 days ago · 4 km deep · 14 km away
  16. 2.46 km ENE of Seven Trees, California · 17553 days ago · 5 km deep · 67 km away
  17. 1.610 km S of Tres Pinos, California · 17553 days ago · 3 km deep · 15 km away
  18. 2.26 km E of East Foothills, California · 17552 days ago · 7 km deep · 71 km away
  19. 1.929 km SE of Big Sur, California · 17550 days ago · 10 km deep · 87 km away
  20. 1.627 km NE of Soledad, California · 17550 days ago · 9 km deep · 34 km away
  21. 1.510 km S of Tres Pinos, California · 17549 days ago · 3 km deep · 14 km away
  22. 3.210 km S of Tres Pinos, California · 17549 days ago · 4 km deep · 14 km away
  23. 1.99 km S of Tres Pinos, California · 17549 days ago · 4 km deep · 13 km away
  24. 2.19 km S of Tres Pinos, California · 17549 days ago · 3 km deep · 14 km away
  25. 1.79 km S of Tres Pinos, California · 17548 days ago · 4 km deep · 14 km away
  26. 1.89 km S of Tres Pinos, California · 17548 days ago · 4 km deep · 14 km away
  27. 2.36 km E of East Foothills, California · 17548 days ago · 7 km deep · 71 km away
  28. 2.25 km SE of Alum Rock, California · 17548 days ago · 3 km deep · 69 km away
  29. 2.36 km NE of Ridgemark, California · 17547 days ago · 6 km deep · 4 km away
  30. 1.75 km SSE of San Juan Bautista, California · 17547 days ago · 5 km deep · 15 km away
  31. 1.89 km S of Tres Pinos, California · 17547 days ago · 4 km deep · 13 km away
  32. 3.39 km S of Tres Pinos, California · 17546 days ago · 4 km deep · 14 km away
  33. 3.010 km S of Tres Pinos, California · 17546 days ago · 4 km deep · 14 km away
  34. 2.410 km S of Tres Pinos, California · 17546 days ago · 5 km deep · 14 km away
  35. 1.610 km S of Tres Pinos, California · 17546 days ago · 4 km deep · 14 km away
  36. 2.910 km S of Tres Pinos, California · 17546 days ago · 4 km deep · 14 km away
  37. 3.910 km S of Tres Pinos, California · 17546 days ago · 4 km deep · 14 km away
  38. 2.810 km S of Tres Pinos, California · 17546 days ago · 4 km deep · 14 km away
  39. 2.5Central California · 17546 days ago · 1 km deep · 50 km away
  40. 1.69 km S of Tres Pinos, California · 17546 days ago · 4 km deep · 14 km away
  41. 3.810 km S of Tres Pinos, California · 17546 days ago · 4 km deep · 14 km away
  42. 2.2Central California · 17546 days ago · 4 km deep · 14 km away
  43. 2.410 km S of Tres Pinos, California · 17546 days ago · 4 km deep · 15 km away
  44. 2.710 km S of Tres Pinos, California · 17546 days ago · 5 km deep · 14 km away
  45. 2.210 km S of Tres Pinos, California · 17546 days ago · 4 km deep · 15 km away
  46. 1.8Central California · 17546 days ago · 4 km deep · 15 km away
  47. 2.3Central California · 17546 days ago · 4 km deep · 15 km away
  48. 2.710 km S of Tres Pinos, California · 17546 days ago · 4 km deep · 15 km away
  49. 2.9Central California · 17545 days ago · 5 km deep · 14 km away
  50. 2.010 km S of Tres Pinos, California · 17545 days ago · 4 km deep · 14 km away
  51. 3.0Central California · 17545 days ago · 4 km deep · 14 km away
  52. 2.011 km S of Tres Pinos, California · 17545 days ago · 4 km deep · 15 km away
  53. 2.39 km NE of San Martin, California · 17544 days ago · 7 km deep · 41 km away
  54. 1.610 km SSW of Tres Pinos, California · 17544 days ago · 12 km deep · 14 km away
  55. 1.817 km SSE of Tres Pinos, California · 17544 days ago · 8 km deep · 22 km away
  56. 2.19 km S of Tres Pinos, California · 17543 days ago · 4 km deep · 14 km away
  57. 2.38 km SSE of Tres Pinos, California · 17543 days ago · 5 km deep · 13 km away
  58. 3.28 km NE of Interlaken, California · 17543 days ago · 4 km deep · 35 km away
  59. 1.69 km SSE of Tres Pinos, California · 17543 days ago · 5 km deep · 13 km away
  60. 1.88 km NE of Interlaken, California · 17543 days ago · 4 km deep · 35 km away

The first 60 of 157.

Before

  1. 2.323 km NE of Greenfield, California · 17560 days ago · 9 km deep · 48 km away
  2. 1.915 km SW of Los Banos, California · 17561 days ago · 6 km deep · 36 km away
  3. 1.87 km NE of Interlaken, California · 17561 days ago · 4 km deep · 35 km away
  4. 1.713 km E of Seven Trees, California · 17561 days ago · 1 km deep · 60 km away
  5. 3.36 km ENE of Seven Trees, California · 17562 days ago · 5 km deep · 67 km away
  6. 2.46 km ENE of Seven Trees, California · 17562 days ago · 6 km deep · 67 km away
  7. 2.46 km ENE of Seven Trees, California · 17563 days ago · 5 km deep · 67 km away
  8. 1.710 km ESE of East Foothills, California · 17564 days ago · 7 km deep · 66 km away
  9. 1.716 km NE of East Foothills, California · 17564 days ago · 6 km deep · 80 km away
  10. 2.0Central California · 17564 days ago · 2 km deep · 28 km away
  11. 2.415 km SSE of Tres Pinos, California · 17565 days ago · 6 km deep · 20 km away
  12. 2.216 km SSE of Tres Pinos, California · 17565 days ago · 6 km deep · 20 km away
  13. 2.016 km SSE of Tres Pinos, California · 17565 days ago · 6 km deep · 21 km away
  14. 1.816 km SSE of Tres Pinos, California · 17565 days ago · 6 km deep · 20 km away
  15. 2.616 km SSE of Tres Pinos, California · 17565 days ago · 6 km deep · 20 km away
  16. 1.510 km ESE of East Foothills, California · 17565 days ago · 8 km deep · 66 km away
  17. 2.410 km ESE of East Foothills, California · 17565 days ago · 8 km deep · 67 km away
  18. 2.010 km ESE of East Foothills, California · 17565 days ago · 8 km deep · 66 km away
  19. 1.610 km ESE of East Foothills, California · 17566 days ago · 7 km deep · 67 km away
  20. 1.810 km ESE of East Foothills, California · 17566 days ago · 7 km deep · 67 km away

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From the USGS Earthquake Hazards Program and its partner networks, event nc1042078. Read Thu, Oct 1, 2026, 7:33 PM UTC.