California earthquakes

M1.8 earthquake 1 km SE of Waldon, California

A magnitude 1.8 earthquake struck 1 km SE of Waldon, California on Mon, Apr 27, 1987, 1:59 PM PDT (20:59 UTC), 5 km (3 mi) below the surface.

A larger quake followed: M4.0 4 km ESE of Piedmont, California. This one was a foreshock.

Waldon 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
1987-04-27 20:59:55 UTC
Depth
4.6 km (2.8 mi), shallow
Epicenter
37.915° N, 122.043° 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 0.8 km horizontally, 1.4 km in depth
Magnitude uncertainty
±0.09
Depth from
From location
Station coverage gap
197°, poorly surrounded by stations
Stations used
10

Nearest places

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

Nearby

Within 100 km, magnitude 1.5 and up: 107 in the 60 days after this one and 52 in the 30 days before it.

After

  1. 1.80 km E of Walnut Creek, California · 14399 days ago · 4 km deep · 1 km away
  2. 2.61 km E of Walnut Creek, California · 14399 days ago · 5 km deep · 1 km away
  3. 2.216 km SSE of Livermore, California · 14399 days ago · 8 km deep · 52 km away
  4. 2.314 km E of Seven Trees, California · 14398 days ago · 3 km deep · 76 km away
  5. 1.90 km NNE of Acalanes Ridge, California · 14398 days ago · 7 km deep · 3 km away
  6. 1.616 km SSE of Livermore, California · 14398 days ago · 3 km deep · 52 km away
  7. 1.97 km WSW of Kenwood, California · 14397 days ago · 2 km deep · 73 km away
  8. 1.76 km WNW of Kenwood, California · 14396 days ago · 5 km deep · 76 km away
  9. 1.714 km E of Seven Trees, California · 14396 days ago · 3 km deep · 76 km away
  10. 1.77 km W of Kenwood, California · 14396 days ago · 6 km deep · 76 km away
  11. 2.05 km SE of Pleasanton, California · 14396 days ago · 6 km deep · 36 km away
  12. 1.75 km SE of Pleasanton, California · 14396 days ago · 6 km deep · 37 km away
  13. 1.53 km SSW of Alamo, California · 14395 days ago · 12 km deep · 10 km away
  14. 2.010 km WNW of Bolinas, California · 14395 days ago · 6 km deep · 65 km away
  15. 1.714 km E of Seven Trees, California · 14395 days ago · 2 km deep · 76 km away
  16. 2.212 km NNE of Angwin, California · 14394 days ago · 8 km deep · 90 km away
  17. 1.815 km SSE of Livermore, California · 14394 days ago · 4 km deep · 51 km away
  18. 2.38 km SSW of Calistoga, California · 14394 days ago · 6 km deep · 82 km away
  19. 2.30 km E of Walnut Creek, California · 14394 days ago · 5 km deep · 1 km away
  20. 1.613 km N of Morgan Hill, California · 14391 days ago · 3 km deep · 82 km away
  21. 1.7Northern California · 14390 days ago · 7 km deep · 99 km away
  22. 1.90 km W of Walnut Creek, California · 14389 days ago · 5 km deep · 2 km away
  23. 1.89 km ESE of East Foothills, California · 14389 days ago · 1 km deep · 70 km away
  24. 1.77 km WSW of Calistoga, California · 14389 days ago · 0 km deep · 89 km away
  25. 1.614 km ESE of East Foothills, California · 14389 days ago · 1 km deep · 72 km away
  26. 4.04 km ESE of Piedmont, California · 14386 days ago · 4 km deep · 17 km away
  27. 1.92 km NNW of Concord, California · 14386 days ago · 15 km deep · 9 km away
  28. 2.73 km ESE of Piedmont, California · 14386 days ago · 4 km deep · 17 km away
  29. 1.613 km N of Morgan Hill, California · 14386 days ago · 3 km deep · 83 km away
  30. 2.4Northern California · 14385 days ago · 14 km deep · 99 km away
  31. 1.75 km NNE of San Leandro, California · 14384 days ago · 6 km deep · 18 km away
  32. 2.54 km SW of Glen Ellen, California · 14384 days ago · 6 km deep · 65 km away
  33. 1.714 km ESE of Hidden Valley Lake, California · 14383 days ago · 1 km deep · 98 km away
  34. 2.14 km SW of Glen Ellen, California · 14383 days ago · 6 km deep · 65 km away
  35. 2.14 km SW of Glen Ellen, California · 14383 days ago · 6 km deep · 65 km away
  36. 2.87 km NNE of East Foothills, California · 14382 days ago · 7 km deep · 57 km away
  37. 1.812 km NE of East Foothills, California · 14382 days ago · 5 km deep · 56 km away
  38. 2.02 km SE of Larkfield-Wikiup, California · 14382 days ago · 4 km deep · 88 km away
  39. 2.613 km ENE of East Foothills, California · 14382 days ago · 7 km deep · 61 km away
  40. 2.20 km S of Clayton, California · 14381 days ago · 3 km deep · 10 km away
  41. 2.08 km WNW of Davenport, California · 14381 days ago · 12 km deep · 99 km away
  42. 2.315 km SSE of Livermore, California · 14379 days ago · 4 km deep · 51 km away
  43. 2.114 km N of Morgan Hill, California · 14379 days ago · 3 km deep · 80 km away
  44. 1.52 km SSE of Calistoga, California · 14378 days ago · 2 km deep · 85 km away
  45. 1.64 km E of Union City, California · 14377 days ago · 7 km deep · 36 km away
  46. 1.814 km N of Morgan Hill, California · 14377 days ago · 6 km deep · 81 km away
  47. 1.73 km SW of Hillsborough, California · 14376 days ago · 9 km deep · 51 km away
  48. 1.86 km SSE of Cottonwood, California · 14376 days ago · 0 km deep · 77 km away
  49. 1.618 km NE of East Foothills, California · 14376 days ago · 4 km deep · 55 km away
  50. 2.018 km NE of East Foothills, California · 14376 days ago · 4 km deep · 55 km away
  51. 1.816 km E of Seven Trees, California · 14374 days ago · 6 km deep · 78 km away
  52. 1.65 km N of Winters, California · 14374 days ago · 1 km deep · 74 km away
  53. 2.11 km NNW of Winters, California · 14374 days ago · 2 km deep · 70 km away
  54. 1.93 km SSW of Broadmoor, California · 14372 days ago · 8 km deep · 49 km away
  55. 1.514 km E of Seven Trees, California · 14371 days ago · 2 km deep · 76 km away
  56. 1.50 km NE of Pleasant Hill, California · 14371 days ago · 9 km deep · 4 km away
  57. 1.61 km NE of Pleasant Hill, California · 14371 days ago · 8 km deep · 5 km away
  58. 3.43 km N of San Leandro, California · 14371 days ago · 5 km deep · 20 km away
  59. 3.0Northern California · 14371 days ago · 5 km deep · 20 km away
  60. 2.43 km NNE of San Leandro, California · 14371 days ago · 5 km deep · 20 km away

The first 60 of 107.

Before

  1. 2.21 km E of Walnut Creek, California · 14400 days ago · 5 km deep · 1 km away
  2. 2.00 km E of Walnut Creek, California · 14401 days ago · 3 km deep · 1 km away
  3. 1.77 km E of East Foothills, California · 14402 days ago · 8 km deep · 67 km away
  4. 3.113 km ESE of Alum Rock, California · 14404 days ago · 7 km deep · 74 km away
  5. 1.81 km ENE of San Ramon, California · 14404 days ago · 7 km deep · 16 km away
  6. 2.51 km ENE of San Ramon, California · 14404 days ago · 8 km deep · 16 km away
  7. 1.57 km ESE of East Foothills, California · 14405 days ago · 1 km deep · 67 km away
  8. 1.84 km W of Moskowite Corner, California · 14405 days ago · 7 km deep · 61 km away
  9. 2.27 km NNE of East Foothills, California · 14405 days ago · 7 km deep · 57 km away
  10. 1.90 km NW of Walnut Creek, California · 14406 days ago · 6 km deep · 2 km away
  11. 1.87 km NNE of East Foothills, California · 14406 days ago · 7 km deep · 57 km away
  12. 3.27 km NNE of East Foothills, California · 14406 days ago · 7 km deep · 57 km away
  13. 1.71 km ENE of San Ramon, California · 14406 days ago · 8 km deep · 16 km away
  14. 2.11 km NE of San Ramon, California · 14406 days ago · 7 km deep · 16 km away
  15. 2.71 km ENE of San Ramon, California · 14406 days ago · 8 km deep · 16 km away
  16. 1.513 km NNE of Angwin, California · 14407 days ago · 4 km deep · 91 km away
  17. 2.78 km NE of San Martin, California · 14408 days ago · 7 km deep · 98 km away
  18. 1.81 km ENE of Walnut Creek, California · 14408 days ago · 5 km deep · 1 km away
  19. 2.36 km NNE of East Foothills, California · 14409 days ago · 5 km deep · 59 km away
  20. 1.610 km ESE of Seven Trees, California · 14410 days ago · 2 km deep · 80 km away

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Sources

From the USGS Earthquake Hazards Program and its partner networks, event nc99342 (also filed as usp00034ht). Read Tue, Sep 29, 2026, 7:59 AM UTC.