California earthquakes

M1.8 earthquake 1 km WNW of Concord, California

A magnitude 1.8 earthquake struck 1 km WNW of Concord, California on Thu, May 28, 1987, 3:34 AM PDT (10:34 UTC), 12 km (8 mi) below the surface.

A larger quake followed: M3.6 13 km N of Morgan Hill, California. This one was a foreshock.

Concord 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
1987-05-28 10:34:59 UTC
Depth
12.3 km (7.7 mi), shallow
Epicenter
37.983° N, 122.041° 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, 0.5 km in depth
Magnitude uncertainty
±0.14
Depth from
From location
Station coverage gap
44°
Stations used
32

Nearest places

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

Nearby

Within 100 km, magnitude 1.5 and up: 82 in the 60 days after this one and 63 in the 30 days before it.

After

  1. 2.62 km NNE of San Leandro, California · 14368 days ago · 4 km deep · 28 km away
  2. 1.814 km N of Morgan Hill, California · 14367 days ago · 5 km deep · 88 km away
  3. 1.619 km E of East Foothills, California · 14367 days ago · 5 km deep · 80 km away
  4. 2.63 km ENE of East Foothills, California · 14366 days ago · 1 km deep · 69 km away
  5. 1.614 km ENE of Angwin, California · 14365 days ago · -1 km deep · 74 km away
  6. 3.22 km NE of San Leandro, California · 14365 days ago · 4 km deep · 28 km away
  7. 2.82 km NNE of San Leandro, California · 14365 days ago · 4 km deep · 28 km away
  8. 1.616 km SSE of Livermore, California · 14365 days ago · 8 km deep · 57 km away
  9. 2.63 km NNE of San Leandro, California · 14362 days ago · 4 km deep · 27 km away
  10. 2.014 km E of Seven Trees, California · 14362 days ago · 4 km deep · 84 km away
  11. 1.814 km E of Seven Trees, California · 14362 days ago · 3 km deep · 84 km away
  12. 1.60 km NE of North Gate, California · 14361 days ago · 11 km deep · 9 km away
  13. 1.718 km NE of East Foothills, California · 14361 days ago · 7 km deep · 61 km away
  14. 1.514 km N of Morgan Hill, California · 14361 days ago · 6 km deep · 87 km away
  15. 1.86 km W of Glen Ellen, California · 14361 days ago · 2 km deep · 64 km away
  16. 2.713 km N of Morgan Hill, California · 14360 days ago · 6 km deep · 88 km away
  17. 2.22 km N of Ashland, California · 14357 days ago · 5 km deep · 31 km away
  18. 2.515 km E of Seven Trees, California · 14356 days ago · 6 km deep · 84 km away
  19. 2.814 km N of Morgan Hill, California · 14356 days ago · 6 km deep · 88 km away
  20. 1.6Northern California · 14356 days ago · 5 km deep · 37 km away
  21. 1.93 km S of Fairview, California · 14355 days ago · 4 km deep · 37 km away
  22. 1.69 km E of Hidden Valley Lake, California · 14355 days ago · 6 km deep · 99 km away
  23. 3.12 km NNW of Communications Hill, California · 14353 days ago · 10 km deep · 77 km away
  24. 1.610 km E of Blackhawk, California · 14352 days ago · 18 km deep · 28 km away
  25. 1.93 km NNE of Windsor, California · 14351 days ago · 2 km deep · 94 km away
  26. 1.714 km SE of Hidden Valley Lake, California · 14350 days ago · -1 km deep · 90 km away
  27. 2.45 km N of Port Costa, California · 14349 days ago · 10 km deep · 17 km away
  28. 2.218 km NE of East Foothills, California · 14349 days ago · 6 km deep · 61 km away
  29. 2.017 km NNE of Angwin, California · 14345 days ago · 9 km deep · 87 km away
  30. 2.510 km E of Blackhawk, California · 14344 days ago · 13 km deep · 27 km away
  31. 1.61 km N of Kensington, California · 14344 days ago · 6 km deep · 22 km away
  32. 2.03 km SW of Moskowite Corner, California · 14344 days ago · 8 km deep · 52 km away
  33. 1.615 km SE of Livermore, California · 14343 days ago · 2 km deep · 57 km away
  34. 1.519 km SSE of Livermore, California · 14343 days ago · 7 km deep · 61 km away
  35. 1.63 km SSW of Hillsborough, California · 14342 days ago · 6 km deep · 57 km away
  36. 1.914 km E of Seven Trees, California · 14341 days ago · 1 km deep · 83 km away
  37. 2.36 km NE of East Foothills, California · 14341 days ago · 10 km deep · 67 km away
  38. 1.619 km SSE of Livermore, California · 14340 days ago · 3 km deep · 60 km away
  39. 1.813 km ENE of East Foothills, California · 14338 days ago · 7 km deep · 72 km away
  40. 1.812 km NNE of East Foothills, California · 14337 days ago · 4 km deep · 62 km away
  41. 1.76 km WNW of Kenwood, California · 14333 days ago · 11 km deep · 71 km away
  42. 1.612 km E of Blackhawk, California · 14333 days ago · 16 km deep · 30 km away
  43. 3.31 km NNE of Waldon, California · 14333 days ago · 11 km deep · 5 km away
  44. 2.33 km NNE of Pittsburg, California · 14332 days ago · 19 km deep · 17 km away
  45. 2.03 km SSE of Concord, California · 14332 days ago · 10 km deep · 5 km away
  46. 1.92 km N of Larkfield-Wikiup, California · 14330 days ago · 5 km deep · 87 km away
  47. 1.613 km N of Morgan Hill, California · 14329 days ago · 6 km deep · 88 km away
  48. 1.514 km NNE of Morgan Hill, California · 14329 days ago · 3 km deep · 91 km away
  49. 2.113 km N of Morgan Hill, California · 14328 days ago · 5 km deep · 88 km away
  50. 2.05 km NE of Penngrove, California · 14328 days ago · 4 km deep · 64 km away
  51. 3.613 km N of Morgan Hill, California · 14328 days ago · 6 km deep · 88 km away
  52. 1.612 km N of Morgan Hill, California · 14327 days ago · 7 km deep · 90 km away
  53. 2.013 km N of Morgan Hill, California · 14327 days ago · 5 km deep · 88 km away
  54. 1.615 km SSE of Livermore, California · 14326 days ago · 3 km deep · 56 km away
  55. 2.412 km E of Blackhawk, California · 14326 days ago · 10 km deep · 30 km away
  56. 2.515 km SSE of Livermore, California · 14326 days ago · 2 km deep · 57 km away
  57. 1.715 km SSE of Livermore, California · 14326 days ago · 2 km deep · 57 km away
  58. 2.115 km SSE of Livermore, California · 14326 days ago · 2 km deep · 56 km away
  59. 2.03 km ESE of Berkeley, California · 14325 days ago · 11 km deep · 22 km away
  60. 2.412 km ESE of East Foothills, California · 14323 days ago · 6 km deep · 79 km away

The first 60 of 82.

Before

  1. 1.612 km ESE of East Foothills, California · 14368 days ago · 5 km deep · 80 km away
  2. 2.04 km ESE of San Ramon, California · 14369 days ago · 7 km deep · 26 km away
  3. 1.68 km ESE of East Foothills, California · 14369 days ago · 2 km deep · 76 km away
  4. 2.34 km ESE of San Ramon, California · 14369 days ago · 7 km deep · 26 km away
  5. 1.94 km ESE of San Ramon, California · 14369 days ago · 3 km deep · 26 km away
  6. 2.53 km NNE of San Leandro, California · 14369 days ago · 5 km deep · 27 km away
  7. 2.23 km N of San Leandro, California · 14370 days ago · 4 km deep · 27 km away
  8. 2.43 km NNE of San Leandro, California · 14370 days ago · 5 km deep · 27 km away
  9. 3.0Northern California · 14370 days ago · 5 km deep · 27 km away
  10. 3.43 km N of San Leandro, California · 14370 days ago · 5 km deep · 27 km away
  11. 1.61 km NE of Pleasant Hill, California · 14370 days ago · 8 km deep · 3 km away
  12. 1.50 km NE of Pleasant Hill, California · 14370 days ago · 9 km deep · 3 km away
  13. 1.514 km E of Seven Trees, California · 14370 days ago · 2 km deep · 83 km away
  14. 1.93 km SSW of Broadmoor, California · 14371 days ago · 8 km deep · 54 km away
  15. 2.11 km NNW of Winters, California · 14373 days ago · 2 km deep · 62 km away
  16. 1.65 km N of Winters, California · 14373 days ago · 1 km deep · 66 km away
  17. 1.816 km E of Seven Trees, California · 14373 days ago · 6 km deep · 85 km away
  18. 2.018 km NE of East Foothills, California · 14375 days ago · 4 km deep · 61 km away
  19. 1.618 km NE of East Foothills, California · 14375 days ago · 4 km deep · 61 km away
  20. 1.86 km SSE of Cottonwood, California · 14375 days ago · 0 km deep · 70 km away

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Sources

From the USGS Earthquake Hazards Program and its partner networks, event nc101045. Read Mon, Sep 28, 2026, 6:22 AM UTC.