M1.8 earthquake 1 km E of Waldon, California

Magnitude

1.8 (Md, duration), micro

Magnitude from

Northern California Seismic System

Local time

Mon, Jun 27, 1983, 4:57 PM PDT

UTC

1983-06-27 23:57:27 UTC

Depth

9.4 km (5.8 mi), shallow

Epicenter

37.928° N, 122.038° W

Region

California

Tsunami flag

No

Status

Reviewed by a seismologist

Location uncertainty

About 0.2 km horizontally, 0.3 km in depth

Magnitude uncertainty

±0.11

Depth from

From location

Station coverage gap

38°

Stations used

28

• Waldon, CaliforniaPopulation 5,364. Forecast2 kmE
• Pleasant Hill, CaliforniaPopulation 34,810. Forecast3 kmSE
• Concord, CaliforniaPopulation 128,667. Forecast6 kmS
• Los Angeles, CaliforniaPopulation 3,820,914. Forecast550 kmNW

After

1. 2.07 km ENE of Seven Trees, CaliforniaTue, Jun 28, 10:03 PM PDT · 15801 days ago · 8 km deep · 72 km away
2. 1.94 km NNE of Pittsburg, CaliforniaWed, Jun 29, 3:46 PM PDT · 15800 days ago · 15 km deep · 22 km away
3. 1.56 km E of Fremont, CaliforniaThu, Jun 30, 1:27 PM PDT · 15799 days ago · 5 km deep · 45 km away
4. 1.713 km ESE of Hidden Valley Lake, CaliforniaThu, Jun 30, 5:35 PM PDT · 15799 days ago · 2 km deep · 98 km away
5. 2.08 km ESE of East Foothills, CaliforniaThu, Jun 30, 7:44 PM PDT · 15799 days ago · 3 km deep · 69 km away
6. 2.26 km NE of East Foothills, CaliforniaFri, Jul 1, 1:30 AM PDT · 15799 days ago · 5 km deep · 62 km away
7. 2.022 km W of Diablo Grande, CaliforniaFri, Jul 1, 2:16 AM PDT · 15799 days ago · 6 km deep · 71 km away
8. 2.016 km NE of East Foothills, CaliforniaFri, Jul 1, 4:02 PM PDT · 15798 days ago · 8 km deep · 58 km away
9. 2.15 km NW of San Leandro, CaliforniaSat, Jul 2, 2:48 PM PDT · 15797 days ago · 11 km deep · 23 km away
10. 1.54 km WSW of Loyola, CaliforniaSat, Jul 2, 9:42 PM PDT · 15797 days ago · 5 km deep · 66 km away
11. 1.69 km NE of San Martin, CaliforniaSun, Jul 3, 10:18 PM PDT · 15796 days ago · 6 km deep · 97 km away
12. 1.56 km NE of Rohnert Park, CaliforniaMon, Jul 4, 3:52 AM PDT · 15796 days ago · 0 km deep · 73 km away
13. 2.01 km SSE of Green Valley, CaliforniaMon, Jul 4, 7:49 AM PDT · 15796 days ago · 11 km deep · 37 km away
14. 2.27 km E of East Foothills, CaliforniaMon, Jul 4, 10:46 PM PDT · 15795 days ago · 6 km deep · 68 km away
15. 2.317 km W of Diablo Grande, CaliforniaWed, Jul 6, 9:55 PM PDT · 15793 days ago · 6 km deep · 77 km away
16. 2.414 km NNE of Morgan Hill, CaliforniaFri, Jul 8, 12:31 PM PDT · 15792 days ago · 4 km deep · 86 km away
17. 1.73 km NNE of San Leandro, CaliforniaFri, Jul 8, 4:16 PM PDT · 15791 days ago · 7 km deep · 21 km away
18. 1.820 km SSE of Livermore, CaliforniaSat, Jul 9, 3:56 PM PDT · 15790 days ago · 6 km deep · 57 km away
19. 2.42 km E of East Foothills, CaliforniaMon, Jul 11, 6:03 AM PDT · 15789 days ago · 5 km deep · 64 km away
20. 1.83 km N of Larkfield-Wikiup, CaliforniaTue, Jul 12, 2:29 AM PDT · 15788 days ago · 7 km deep · 93 km away
21. 1.56 km NE of Rohnert Park, CaliforniaWed, Jul 13, 5:05 AM PDT · 15787 days ago · 4 km deep · 73 km away
22. 1.62 km ENE of Pacifica, CaliforniaWed, Jul 13, 9:37 PM PDT · 15786 days ago · 7 km deep · 51 km away
23. 2.44 km NNW of San Leandro, CaliforniaThu, Jul 14, 12:27 AM PDT · 15786 days ago · 11 km deep · 22 km away
24. 2.314 km E of Seven Trees, CaliforniaThu, Jul 14, 6:40 PM PDT · 15785 days ago · 8 km deep · 76 km away
25. 1.914 km E of Seven Trees, CaliforniaFri, Jul 15, 3:12 AM PDT · 15785 days ago · 2 km deep · 78 km away
26. 1.75 km WSW of Moskowite Corner, CaliforniaFri, Jul 15, 8:06 PM PDT · 15784 days ago · 14 km deep · 58 km away
27. 2.19 km NE of Blackhawk, CaliforniaSun, Jul 17, 2:06 PM PDT · 15782 days ago · 1 km deep · 20 km away
28. 1.611 km SE of Hidden Valley Lake, CaliforniaWed, Jul 20, 10:02 AM PDT · 15780 days ago · 2 km deep · 98 km away
29. 1.81 km SSW of Alamo, CaliforniaThu, Jul 21, 9:23 PM PDT · 15778 days ago · 6 km deep · 10 km away
30. 2.07 km W of Kenwood, CaliforniaFri, Jul 22, 8:45 PM PDT · 15777 days ago · 6 km deep · 75 km away
31. 1.911 km ESE of Hidden Valley Lake, CaliforniaSat, Jul 23, 5:32 AM PDT · 15777 days ago · 6 km deep · 98 km away
32. 1.84 km WSW of Moskowite Corner, CaliforniaSat, Jul 23, 7:46 AM PDT · 15777 days ago · 7 km deep · 59 km away
33. 2.17 km ESE of Santa Rosa, CaliforniaSat, Jul 23, 3:44 PM PDT · 15776 days ago · 6 km deep · 76 km away
34. 2.37 km WSW of Moskowite Corner, CaliforniaSun, Jul 24, 2:08 AM PDT · 15776 days ago · 8 km deep · 58 km away
35. 1.511 km SE of Hidden Valley Lake, CaliforniaSun, Jul 24, 7:53 PM PDT · 15775 days ago · 3 km deep · 98 km away
36. 2.12 km E of San Leandro, CaliforniaMon, Jul 25, 3:30 PM PDT · 15774 days ago · 2 km deep · 24 km away
37. 2.514 km NE of Morgan Hill, CaliforniaTue, Jul 26, 9:05 AM PDT · 15774 days ago · 7 km deep · 91 km away
38. 1.817 km ENE of East Foothills, CaliforniaTue, Jul 26, 9:34 PM PDT · 15773 days ago · 5 km deep · 67 km away
39. 2.03 km N of East Foothills, CaliforniaWed, Jul 27, 4:14 PM PDT · 15772 days ago · 0 km deep · 60 km away
40. 1.99 km NE of San Martin, CaliforniaThu, Jul 28, 2:40 AM PDT · 15772 days ago · 7 km deep · 98 km away
41. 1.613 km SE of Sunol, CaliforniaThu, Jul 28, 6:26 AM PDT · 15772 days ago · 4 km deep · 51 km away
42. 1.69 km ESE of East Foothills, CaliforniaThu, Jul 28, 8:18 AM PDT · 15772 days ago · 8 km deep · 70 km away
43. 2.811 km SW of Muir Beach, CaliforniaThu, Jul 28, 11:59 AM PDT · 15772 days ago · 6 km deep · 57 km away
44. 2.916 km NE of East Foothills, CaliforniaThu, Jul 28, 5:03 PM PDT · 15771 days ago · 6 km deep · 61 km away
45. 1.68 km W of Calistoga, CaliforniaFri, Jul 29, 7:33 AM PDT · 15771 days ago · 7 km deep · 92 km away
46. 2.515 km SE of Livermore, CaliforniaSun, Jul 31, 9:58 PM PDT · 15768 days ago · 2 km deep · 52 km away
47. 2.36 km ESE of Santa Rosa, CaliforniaMon, Aug 1, 8:11 PM PDT · 15767 days ago · 0 km deep · 76 km away
48. 1.91 km W of Broadmoor, CaliforniaTue, Aug 2, 12:34 AM PDT · 15767 days ago · 10 km deep · 48 km away
49. 2.39 km ESE of East Foothills, CaliforniaTue, Aug 2, 1:02 AM PDT · 15767 days ago · 3 km deep · 71 km away
50. 1.99 km ESE of East Foothills, CaliforniaTue, Aug 2, 8:18 AM PDT · 15767 days ago · 3 km deep · 71 km away
51. 2.02 km E of North Gate, CaliforniaThu, Aug 4, 9:15 AM PDT · 15765 days ago · 11 km deep · 6 km away
52. 2.39 km ESE of East Foothills, CaliforniaFri, Aug 5, 12:33 PM PDT · 15764 days ago · 7 km deep · 70 km away
53. 1.69 km ESE of East Foothills, CaliforniaFri, Aug 5, 12:34 PM PDT · 15764 days ago · 7 km deep · 70 km away
54. 1.85 km WNW of Camanche Village, CaliforniaFri, Aug 5, 1:21 PM PDT · 15763 days ago · 5 km deep · 97 km away
55. 1.58 km E of East Foothills, CaliforniaSat, Aug 6, 2:27 AM PDT · 15763 days ago · 7 km deep · 68 km away
56. 2.01 km E of Alamo, CaliforniaSun, Aug 7, 1:34 AM PDT · 15762 days ago · 9 km deep · 9 km away
57. 1.713 km NNW of Moskowite Corner, CaliforniaSun, Aug 7, 11:10 PM PDT · 15761 days ago · 0 km deep · 73 km away
58. 2.02 km E of Pacifica, CaliforniaMon, Aug 8, 4:17 AM PDT · 15761 days ago · 8 km deep · 51 km away
59. 1.63 km WSW of San Bruno, CaliforniaMon, Aug 8, 7:26 AM PDT · 15761 days ago · 8 km deep · 50 km away
60. 2.22 km SW of Pittsburg, CaliforniaMon, Aug 8, 3:12 PM PDT · 15760 days ago · 15 km deep · 15 km away

The first 60 of 80.

Before

1. 2.16 km ENE of Santa Rosa, CaliforniaMon, Jun 27, 12:36 AM PDT · 15803 days ago · 10 km deep · 80 km away
2. 1.520 km E of East Foothills, CaliforniaSat, Jun 25, 4:49 AM PDT · 15805 days ago · 6 km deep · 72 km away
3. 2.19 km ESE of East Foothills, CaliforniaFri, Jun 24, 10:59 AM PDT · 15806 days ago · 8 km deep · 70 km away
4. 1.79 km ESE of East Foothills, CaliforniaFri, Jun 24, 10:50 AM PDT · 15806 days ago · 9 km deep · 69 km away
5. 1.76 km S of Green Valley, CaliforniaThu, Jun 23, 12:07 PM PDT · 15807 days ago · 7 km deep · 31 km away
6. 1.55 km NNE of Pleasanton, CaliforniaThu, Jun 23, 6:53 AM PDT · 15807 days ago · 12 km deep · 30 km away
7. 2.76 km NNE of Pleasanton, CaliforniaThu, Jun 23, 6:51 AM PDT · 15807 days ago · 15 km deep · 29 km away
8. 1.65 km NNE of Pleasanton, CaliforniaThu, Jun 23, 6:46 AM PDT · 15807 days ago · 13 km deep · 30 km away
9. 2.05 km NNE of Pleasanton, CaliforniaThu, Jun 23, 6:45 AM PDT · 15807 days ago · 13 km deep · 30 km away
10. 2.65 km NNE of Pleasanton, CaliforniaThu, Jun 23, 6:45 AM PDT · 15807 days ago · 14 km deep · 30 km away
11. 1.75 km NE of Pleasanton, CaliforniaThu, Jun 23, 6:43 AM PDT · 15807 days ago · 13 km deep · 31 km away
12. 2.05 km NNE of Pleasanton, CaliforniaThu, Jun 23, 6:42 AM PDT · 15807 days ago · 14 km deep · 29 km away
13. 1.95 km NNE of Pleasanton, CaliforniaThu, Jun 23, 6:40 AM PDT · 15807 days ago · 13 km deep · 30 km away
14. 1.621 km E of East Foothills, CaliforniaWed, Jun 22, 9:42 AM PDT · 15808 days ago · 7 km deep · 70 km away
15. 2.40 km WSW of Rollingwood, CaliforniaTue, Jun 21, 2:01 AM PDT · 15809 days ago · 5 km deep · 26 km away
16. 1.92 km NE of Pacheco, CaliforniaMon, Jun 20, 9:40 AM PDT · 15810 days ago · 15 km deep · 8 km away
17. 1.79 km N of East Foothills, CaliforniaSun, Jun 19, 5:54 AM PDT · 15811 days ago · 6 km deep · 55 km away
18. 1.61 km W of Pleasant Hill, CaliforniaSat, Jun 18, 10:01 AM PDT · 15812 days ago · 12 km deep · 4 km away
19. 2.416 km NE of East Foothills, CaliforniaFri, Jun 17, 3:50 PM PDT · 15812 days ago · 6 km deep · 58 km away
20. 1.76 km ENE of Penngrove, CaliforniaFri, Jun 17, 6:16 AM PDT · 15813 days ago · 5 km deep · 66 km away

From the USGS Earthquake Hazards Program and its partner networks, event nc1097648. Read Fri, Oct 2, 2026, 7:31 AM UTC.