M1.6 earthquake 3km SSW of Half Moon Bay, CA

Magnitude

1.6 (Md, duration), micro

Magnitude from

Northern California Seismic System

Local time

Sun, Dec 12, 2021, 2:24 AM PST

UTC

2021-12-12 10:24:18 UTC

Depth

9.9 km (6.2 mi), shallow

Epicenter

37.435° N, 122.440° W

Region

California

Tsunami flag

No

Status

Reviewed by a seismologist

Location uncertainty

About 0.3 km horizontally, 0.2 km in depth

Magnitude uncertainty

±0.14

Depth from

From location

Station coverage gap

209°, poorly surrounded by stations

Stations used

40

• Half Moon Bay, CaliforniaPopulation 12,657. Forecast3 kmSSW
• San Mateo, CaliforniaPopulation 103,536. Forecast17 kmSW
• Los Angeles, CaliforniaPopulation 3,820,914. Forecast534 kmNW

After

1. 1.67km WSW of Lagunitas-Forest Knolls, CAMon, Dec 13, 6:35 AM PST · 1756 days ago · 5 km deep · 68 km away
2. 1.63km SE of Concord, CAMon, Dec 13, 10:51 AM PST · 1756 days ago · 12 km deep · 69 km away
3. 2.23km SSW of Half Moon Bay, CAMon, Dec 13, 1:48 PM PST · 1756 days ago · 10 km deep · 0 km away
4. 2.32km SW of Discovery Bay, CAMon, Dec 13, 4:01 PM PST · 1756 days ago · 18 km deep · 89 km away
5. 1.63km SSW of Half Moon Bay, CATue, Dec 14, 2:02 AM PST · 1755 days ago · 10 km deep · 0 km away
6. 1.89km NE of Morgan Hill, CATue, Dec 14, 6:31 PM PST · 1754 days ago · 2 km deep · 81 km away
7. 2.010km E of Alum Rock, CASat, Dec 18, 11:21 AM PST · 1751 days ago · 9 km deep · 65 km away
8. 2.01km N of Pacifica, CASun, Dec 19, 10:02 PM PST · 1749 days ago · 8 km deep · 22 km away · felt by 14
9. 1.71km WNW of Danville, CATue, Dec 21, 10:33 PM PST · 1747 days ago · 8 km deep · 58 km away · felt by 2
10. 1.91km NW of Danville, CAWed, Dec 22, 3:57 AM PST · 1747 days ago · 8 km deep · 58 km away · felt by 3
11. 1.62km NE of San Ramon, CAThu, Dec 23, 4:30 AM PST · 1746 days ago · 10 km deep · 58 km away · felt by 2
12. 1.85km NNE of Alum Rock, CAFri, Dec 24, 9:15 PM PST · 1744 days ago · 0 km deep · 56 km away · felt by 5
13. 2.34km NE of Fairview, CATue, Dec 28, 8:58 PM PST · 1740 days ago · 7 km deep · 48 km away · felt by 27
14. 2.05km ESE of Aromas, CAThu, Dec 30, 4:10 PM PST · 1739 days ago · 5 km deep · 98 km away
15. 1.52km S of Alamo, CAThu, Dec 30, 4:12 PM PST · 1739 days ago · 10 km deep · 57 km away · felt by 3
16. 2.19km E of Alum Rock, CASun, Jan 2, 5:42 AM PST · 1736 days ago · 9 km deep · 63 km away
17. 1.510km ENE of Milpitas, CAMon, Jan 3, 8:47 AM PST · 1735 days ago · 8 km deep · 55 km away
18. 2.62km SW of Colma, CATue, Jan 4, 3:18 AM PST · 1734 days ago · 8 km deep · 26 km away
19. 1.711km NE of Milpitas, CASat, Jan 8, 9:54 AM PST · 1730 days ago · 4 km deep · 55 km away
20. 1.52km NE of Union City, CASat, Jan 8, 6:39 PM PST · 1729 days ago · 5 km deep · 43 km away
21. 1.75km WSW of Pacheco, CAMon, Jan 10, 3:05 PM PST · 1728 days ago · 9 km deep · 65 km away
22. 1.54km WSW of Colma, CAWed, Jan 12, 4:29 PM PST · 1726 days ago · 9 km deep · 26 km away
23. 1.61km NE of San Ramon, CAWed, Jan 12, 9:16 PM PST · 1725 days ago · 10 km deep · 57 km away
24. 2.111km SSW of Brentwood, CAThu, Jan 13, 1:57 PM PST · 1725 days ago · 18 km deep · 74 km away
25. 2.46km N of Diablo, CAThu, Jan 13, 5:21 PM PST · 1725 days ago · 13 km deep · 65 km away · felt by 25
26. 1.99km E of Gilroy, CAThu, Jan 13, 7:30 PM PST · 1724 days ago · 5 km deep · 99 km away · felt by 2
27. 2.39km E of Gilroy, CAFri, Jan 14, 12:56 PM PST · 1724 days ago · 6 km deep · 99 km away
28. 1.62km NNE of San Ramon, CASat, Jan 15, 9:15 AM PST · 1723 days ago · 11 km deep · 58 km away · felt by 2
29. 1.98km E of Fremont, CASat, Jan 15, 2:24 PM PST · 1723 days ago · 7 km deep · 49 km away · felt by 3
30. 1.77km ENE of Gilroy, CASun, Jan 16, 7:19 PM PST · 1721 days ago · 9 km deep · 95 km away
31. 1.65km N of Lafayette, CAFri, Jan 21, 11:21 AM PST · 1717 days ago · 6 km deep · 62 km away
32. 1.64km N of Lafayette, CAFri, Jan 21, 3:37 PM PST · 1717 days ago · 5 km deep · 61 km away · felt by 1
33. 2.25km WNW of Dublin, CAFri, Jan 21, 3:41 PM PST · 1717 days ago · 6 km deep · 51 km away · felt by 12
34. 1.96km WNW of Dublin, CAFri, Jan 21, 3:56 PM PST · 1717 days ago · 8 km deep · 51 km away · felt by 2
35. 1.61km NE of Byron, CASun, Jan 23, 8:55 AM PST · 1715 days ago · 4 km deep · 86 km away
36. 1.51km SE of Pacifica, CAMon, Jan 24, 7:24 AM PST · 1714 days ago · 8 km deep · 19 km away
37. 1.52km NNW of Green Valley, CAMon, Jan 24, 11:55 AM PST · 1714 days ago · 6 km deep · 96 km away
38. 1.612km SW of Mountain House, CATue, Jan 25, 6:19 AM PST · 1713 days ago · 18 km deep · 78 km away
39. 1.512km SW of Mountain House, CATue, Jan 25, 6:19 AM PST · 1713 days ago · 18 km deep · 77 km away
40. 1.93km WSW of American Canyon, CATue, Jan 25, 5:30 PM PST · 1713 days ago · 7 km deep · 82 km away
41. 1.610km NNE of Morgan Hill, CAThu, Jan 27, 2:42 AM PST · 1711 days ago · 3 km deep · 79 km away · felt by 1
42. 1.916km E of Seven Trees, CAThu, Jan 27, 5:04 PM PST · 1711 days ago · 4 km deep · 70 km away
43. 2.84km SE of Aromas, CATue, Feb 1, 7:14 PM PST · 1705 days ago · 8 km deep · 97 km away · felt by 32
44. 2.06km SW of Gilroy, CATue, Feb 1, 10:51 PM PST · 1705 days ago · 4 km deep · 90 km away · felt by 4
45. 2.23km NNW of Diablo, CASun, Feb 6, 2:00 PM PST · 1701 days ago · 9 km deep · 62 km away · felt by 5
46. 3.12km ENE of San Leandro, CASun, Feb 6, 4:01 PM PST · 1701 days ago · 4 km deep · 42 km away · felt by 1,429
47. 1.85km NW of Pittsburg, CASun, Feb 6, 7:25 PM PST · 1700 days ago · 21 km deep · 84 km away · felt by 2
48. 2.716km E of Seven Trees, CAMon, Feb 7, 8:38 AM PST · 1700 days ago · 5 km deep · 70 km away · felt by 37
49. 1.53km E of Aromas, CATue, Feb 8, 1:06 PM PST · 1699 days ago · 2 km deep · 95 km away

Before

1. 1.87km ENE of Gilroy, CAFri, Dec 10, 11:02 AM PST · 1759 days ago · 9 km deep · 96 km away
2. 2.22km E of Pacheco, CAWed, Dec 8, 9:21 AM PST · 1761 days ago · 16 km deep · 70 km away
3. 1.66km WSW of Colma, CAWed, Dec 8, 7:01 AM PST · 1761 days ago · 9 km deep · 26 km away · felt by 2
4. 2.54km N of San Leandro, CASat, Dec 4, 6:08 PM PST · 1764 days ago · 3 km deep · 44 km away · felt by 150
5. 1.81km NE of San Ramon, CAFri, Dec 3, 11:25 PM PST · 1765 days ago · 9 km deep · 57 km away · felt by 1
6. 1.74km S of Portola Valley, CAThu, Dec 2, 7:22 PM PST · 1766 days ago · 6 km deep · 21 km away · felt by 1
7. 1.74km S of Portola Valley, CAThu, Dec 2, 6:32 PM PST · 1766 days ago · 6 km deep · 21 km away
8. 2.79km ENE of Morgan Hill, CATue, Nov 30, 8:07 AM PST · 1769 days ago · 2 km deep · 84 km away · felt by 38
9. 2.01km W of Kensington, CAMon, Nov 29, 7:37 PM PST · 1769 days ago · 5 km deep · 55 km away · felt by 43
10. 2.51km W of Kensington, CAMon, Nov 29, 7:30 PM PST · 1769 days ago · 5 km deep · 54 km away · felt by 965
11. 1.723km WNW of Bonny Doon, CASat, Nov 27, 4:17 PM PST · 1772 days ago · 7 km deep · 36 km away
12. 1.97km ESE of Bethel Island, CASat, Nov 20, 8:33 PM PST · 1778 days ago · 9 km deep · 97 km away
13. 2.211km NW of Morgan Hill, CASat, Nov 20, 8:00 PM PST · 1778 days ago · 6 km deep · 68 km away · felt by 1
14. 1.98km SSW of Brentwood, CASat, Nov 20, 7:27 PM PST · 1778 days ago · 19 km deep · 76 km away · felt by 1
15. 2.112km ENE of Morgan Hill, CASat, Nov 20, 5:24 PM PST · 1779 days ago · 4 km deep · 86 km away
16. 1.75km E of Fremont, CASat, Nov 20, 8:43 AM PST · 1779 days ago · 9 km deep · 47 km away
17. 1.78km WSW of Mountain House, CAFri, Nov 19, 4:41 PM PST · 1780 days ago · 0 km deep · 80 km away
18. 2.44km S of Dillon Beach, CAFri, Nov 19, 2:22 PM PST · 1780 days ago · 10 km deep · 97 km away
19. 1.83km S of Dillon Beach, CAFri, Nov 19, 1:21 PM PST · 1780 days ago · 10 km deep · 98 km away
20. 1.91km NE of San Ramon, CAFri, Nov 19, 3:58 AM PST · 1780 days ago · 10 km deep · 57 km away

From the USGS Earthquake Hazards Program and its partner networks, event nc73662916. Read Sun, Oct 4, 2026, 1:34 PM UTC.