California earthquakes

M1.8 earthquake 4 km SE of Calpella, California

A magnitude 1.8 earthquake struck 4 km SE of Calpella, California on Wed, Apr 19, 1978, 6:30 PM PST (02:30 UTC), 6 km (4 mi) below the surface.

A larger quake followed: M2.0 6 km S of Hopland, California. This one was a foreshock.

Calpella 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
1978-04-20 02:30:21 UTC
Depth
6.0 km (3.7 mi), shallow
Epicenter
39.199° N, 123.170° 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 0.3 km horizontally, 0.8 km in depth
Magnitude uncertainty
±0.07
Depth from
From location
Station coverage gap
128°
Stations used
12

Nearest places

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

Nearby

Within 100 km, magnitude 1.5 and up: 100 in the 60 days after this one and 99 in the 30 days before it.

After

  1. 2.06 km S of Hopland, California · 17687 days ago · 3 km deep · 32 km away
  2. 2.32 km SE of Stonyford, California · 17687 days ago · 6 km deep · 59 km away
  3. 1.73 km ESE of Calpella, California · 17686 days ago · 6 km deep · 2 km away
  4. 1.55 km WSW of Cobb, California · 17686 days ago · 3 km deep · 55 km away
  5. 1.611 km NE of Healdsburg, California · 17685 days ago · 5 km deep · 68 km away
  6. 1.63 km E of Calpella, California · 17685 days ago · 3 km deep · 3 km away
  7. 2.011 km ESE of Boonville, California · 17684 days ago · -1 km deep · 28 km away
  8. 1.53 km SSE of Calpella, California · 17684 days ago · -1 km deep · 1 km away
  9. 2.04 km ESE of Calpella, California · 17683 days ago · 5 km deep · 2 km away
  10. 1.52 km ESE of Calpella, California · 17683 days ago · 4 km deep · 3 km away
  11. 1.66 km WSW of Cobb, California · 17683 days ago · 0 km deep · 55 km away
  12. 1.611 km WSW of Cobb, California · 17683 days ago · 4 km deep · 53 km away
  13. 2.914 km NW of Elk Creek, California · 17683 days ago · 5 km deep · 73 km away
  14. 2.62 km E of Calpella, California · 17681 days ago · 6 km deep · 4 km away
  15. 1.82 km E of Calpella, California · 17681 days ago · 4 km deep · 4 km away
  16. 2.08 km NE of Willits, California · 17681 days ago · 9 km deep · 31 km away
  17. 2.02 km WNW of Clearlake, California · 17681 days ago · 2 km deep · 51 km away
  18. 1.67 km NNE of Clearlake, California · 17680 days ago · 0 km deep · 55 km away
  19. 1.72 km ESE of Calpella, California · 17680 days ago · 5 km deep · 3 km away
  20. 1.74 km SE of Calpella, California · 17680 days ago · 5 km deep · 0 km away
  21. 2.824 km WNW of Elk Creek, California · 17679 days ago · 4 km deep · 60 km away
  22. 1.93 km ESE of Calpella, California · 17678 days ago · 7 km deep · 3 km away
  23. 1.73 km E of Calpella, California · 17678 days ago · 7 km deep · 3 km away
  24. 2.27 km WSW of Cobb, California · 17678 days ago · 4 km deep · 54 km away
  25. 1.86 km W of Cobb, California · 17677 days ago · 2 km deep · 52 km away
  26. 1.96 km W of Cobb, California · 17677 days ago · 2 km deep · 52 km away
  27. 1.87 km ENE of Hidden Valley Lake, California · 17676 days ago · 6 km deep · 73 km away
  28. 1.63 km E of Calpella, California · 17676 days ago · 6 km deep · 3 km away
  29. 1.54 km E of Calpella, California · 17676 days ago · 5 km deep · 3 km away
  30. 2.03 km E of Calpella, California · 17676 days ago · 6 km deep · 3 km away
  31. 1.73 km ESE of Calpella, California · 17675 days ago · 2 km deep · 2 km away
  32. 2.54 km WSW of Cobb, California · 17675 days ago · 1 km deep · 56 km away
  33. 1.83 km SE of Calpella, California · 17675 days ago · 6 km deep · 2 km away
  34. 1.93 km ESE of Calpella, California · 17675 days ago · 3 km deep · 3 km away
  35. 2.125 km NE of Potter Valley, California · 17675 days ago · 14 km deep · 39 km away
  36. 2.03 km E of Calpella, California · 17675 days ago · 7 km deep · 4 km away
  37. 2.06 km SE of Calpella, California · 17675 days ago · 3 km deep · 1 km away
  38. 1.94 km SSE of Calpella, California · 17674 days ago · 4 km deep · 1 km away
  39. 2.35 km SE of Calpella, California · 17674 days ago · 1 km deep · 1 km away
  40. 2.03 km E of Calpella, California · 17674 days ago · 6 km deep · 4 km away
  41. 1.86 km W of Cobb, California · 17674 days ago · 3 km deep · 53 km away
  42. 2.416 km W of Elk Creek, California · 17673 days ago · 4 km deep · 58 km away
  43. 1.93 km SE of Calpella, California · 17673 days ago · 6 km deep · 2 km away
  44. 1.83 km ESE of Calpella, California · 17672 days ago · 4 km deep · 2 km away
  45. 1.58 km WSW of Cobb, California · 17672 days ago · 1 km deep · 54 km away
  46. 1.76 km W of Cobb, California · 17672 days ago · 3 km deep · 53 km away
  47. 2.66 km W of Cobb, California · 17672 days ago · 4 km deep · 53 km away
  48. 1.95 km SE of Calpella, California · 17672 days ago · 5 km deep · 1 km away
  49. 2.23 km ESE of Calpella, California · 17672 days ago · 6 km deep · 2 km away
  50. 2.53 km ESE of Calpella, California · 17670 days ago · 4 km deep · 3 km away
  51. 1.93 km ESE of Calpella, California · 17670 days ago · 2 km deep · 3 km away
  52. 2.54 km E of Calpella, California · 17669 days ago · 2 km deep · 3 km away
  53. 1.64 km ESE of Calpella, California · 17669 days ago · 5 km deep · 2 km away
  54. 2.524 km ENE of Potter Valley, California · 17669 days ago · 0 km deep · 37 km away
  55. 1.84 km ESE of Calpella, California · 17669 days ago · 3 km deep · 2 km away
  56. 1.714 km SSW of Cloverdale, California · 17669 days ago · 0 km deep · 58 km away
  57. 1.88 km SSW of Guinda, California · 17667 days ago · 10 km deep · 94 km away
  58. 2.815 km ESE of Hidden Valley Lake, California · 17667 days ago · 6 km deep · 83 km away
  59. 3.323 km WNW of Elk Creek, California · 17666 days ago · 4 km deep · 67 km away
  60. 3.024 km WNW of Elk Creek, California · 17666 days ago · 11 km deep · 63 km away

The first 60 of 100.

Before

  1. 2.220 km WNW of Jenner, California · 17688 days ago · 0 km deep · 79 km away
  2. 3.221 km WNW of Elk Creek, California · 17689 days ago · 6 km deep · 65 km away
  3. 3.421 km WNW of Elk Creek, California · 17689 days ago · 10 km deep · 65 km away
  4. 1.83 km SE of Calpella, California · 17689 days ago · 5 km deep · 2 km away
  5. 3.023 km WNW of Elk Creek, California · 17689 days ago · 2 km deep · 64 km away
  6. 3.226 km WNW of Elk Creek, California · 17689 days ago · 18 km deep · 58 km away
  7. 2.55 km SE of Calpella, California · 17689 days ago · 5 km deep · 1 km away
  8. 3.219 km WNW of Elk Creek, California · 17689 days ago · 7 km deep · 65 km away
  9. 2.12 km ENE of Calpella, California · 17690 days ago · 6 km deep · 5 km away
  10. 2.36 km SSE of Willits, California · 17690 days ago · 5 km deep · 23 km away
  11. 1.56 km W of Cobb, California · 17690 days ago · 4 km deep · 54 km away
  12. 1.64 km SE of Calpella, California · 17690 days ago · 5 km deep · 1 km away
  13. 2.36 km SSE of Willits, California · 17690 days ago · 3 km deep · 22 km away
  14. 2.38 km NW of Redwood Valley, California · 17691 days ago · 6 km deep · 17 km away
  15. 1.53 km NE of Santa Rosa, California · 17691 days ago · 9 km deep · 92 km away
  16. 2.04 km SE of Calpella, California · 17692 days ago · 4 km deep · 1 km away
  17. 2.04 km E of Calpella, California · 17692 days ago · 2 km deep · 4 km away
  18. 2.64 km WSW of Cobb, California · 17692 days ago · 1 km deep · 56 km away
  19. 1.87 km W of Cobb, California · 17693 days ago · 2 km deep · 52 km away
  20. 2.58 km WSW of Cobb, California · 17693 days ago · 4 km deep · 54 km away

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Sources

From the USGS Earthquake Hazards Program and its partner networks, event nc1039921. Read Tue, Sep 22, 2026, 5:16 PM UTC.