M1.8 earthquake 1km NE of San Ramon, CA
A magnitude 1.8 earthquake struck 1km NE of San Ramon, CA on Fri, Dec 3, 2021, 11:25 PM PST (07:25 UTC), 9 km (6 mi) below the surface.
A larger quake followed: M2.6 2km SW of Colma, CA. This one was a foreshock.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 1.8 (Md, duration), micro
- Magnitude from
- Northern California Seismic System
- Local time
- UTC
- 2021-12-04 07:25:14 UTC
- Depth
- 9.3 km (5.7 mi), shallow
- Epicenter
- 37.786° N, 121.971° W
- Region
- California
- Felt reports
- 1
- Tsunami flag
- No
- Status
- Reviewed by a seismologist
Did you feel it?
1 person reported to the USGS what they felt; the strongest reported shaking was I, not felt shaking.

How well it is located
Reviewed by a seismologist.
- Location uncertainty
- About 0.2 km horizontally, 0.2 km in depth
- Magnitude uncertainty
- ±0.18
- Depth from
- From location
- Station coverage gap
- 62°
- Stations used
- 55
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 1.5 and up: 50 in the 60 days after this one and 45 in the 30 days before it.
After
- 2.54km N of San Leandro, CA · 1765 days ago · 3 km deep · 17 km away · felt by 150
- 1.66km WSW of Colma, CA · 1762 days ago · 9 km deep · 50 km away · felt by 2
- 2.22km E of Pacheco, CA · 1761 days ago · 16 km deep · 23 km away
- 1.87km ENE of Gilroy, CA · 1759 days ago · 9 km deep · 95 km away
- 1.63km SSW of Half Moon Bay, CA · 1758 days ago · 10 km deep · 57 km away
- 1.67km WSW of Lagunitas-Forest Knolls, CA · 1757 days ago · 5 km deep · 73 km away
- 1.63km SE of Concord, CA · 1756 days ago · 12 km deep · 18 km away
- 2.23km SSW of Half Moon Bay, CA · 1756 days ago · 10 km deep · 57 km away
- 2.32km SW of Discovery Bay, CA · 1756 days ago · 18 km deep · 34 km away
- 1.63km SSW of Half Moon Bay, CA · 1756 days ago · 10 km deep · 57 km away
- 1.89km NE of Morgan Hill, CA · 1755 days ago · 2 km deep · 76 km away
- 2.010km E of Alum Rock, CA · 1751 days ago · 9 km deep · 53 km away
- 2.01km N of Pacifica, CA · 1750 days ago · 8 km deep · 49 km away · felt by 14
- 1.71km WNW of Danville, CA · 1748 days ago · 8 km deep · 5 km away · felt by 2
- 1.91km NW of Danville, CA · 1748 days ago · 8 km deep · 5 km away · felt by 3
- 1.62km NE of San Ramon, CA · 1747 days ago · 10 km deep · 1 km away · felt by 2
- 1.85km NNE of Alum Rock, CA · 1745 days ago · 0 km deep · 44 km away · felt by 5
- 2.34km NE of Fairview, CA · 1741 days ago · 7 km deep · 10 km away · felt by 27
- 1.52km S of Alamo, CA · 1739 days ago · 10 km deep · 8 km away · felt by 3
- 1.56km W of Kenwood, CA · 1739 days ago · 6 km deep · 90 km away
- 2.19km E of Alum Rock, CA · 1737 days ago · 9 km deep · 50 km away
- 1.510km ENE of Milpitas, CA · 1735 days ago · 8 km deep · 38 km away
- 2.62km SW of Colma, CA · 1735 days ago · 8 km deep · 46 km away
- 2.16km ENE of Kenwood, CA · 1734 days ago · 9 km deep · 86 km away
- 2.05km W of Yountville, CA · 1731 days ago · 6 km deep · 78 km away
- 1.711km NE of Milpitas, CA · 1730 days ago · 4 km deep · 34 km away
- 1.52km NE of Union City, CA · 1730 days ago · 5 km deep · 20 km away
- 1.75km WSW of Pacheco, CA · 1728 days ago · 9 km deep · 24 km away
- 1.54km WSW of Colma, CA · 1726 days ago · 9 km deep · 48 km away
- 1.61km NE of San Ramon, CA · 1726 days ago · 10 km deep · 0 km away
- 2.111km SSW of Brentwood, CA · 1725 days ago · 18 km deep · 19 km away
- 2.46km N of Diablo, CA · 1725 days ago · 13 km deep · 11 km away · felt by 25
- 1.99km E of Gilroy, CA · 1725 days ago · 5 km deep · 98 km away · felt by 2
- 2.39km E of Gilroy, CA · 1724 days ago · 6 km deep · 98 km away
- 1.62km NNE of San Ramon, CA · 1723 days ago · 11 km deep · 2 km away · felt by 2
- 1.98km E of Fremont, CA · 1723 days ago · 7 km deep · 29 km away · felt by 3
- 1.77km ENE of Gilroy, CA · 1722 days ago · 9 km deep · 94 km away
- 1.65km N of Lafayette, CA · 1717 days ago · 6 km deep · 20 km away
- 1.64km N of Lafayette, CA · 1717 days ago · 5 km deep · 20 km away · felt by 1
- 2.25km WNW of Dublin, CA · 1717 days ago · 6 km deep · 7 km away · felt by 12
- 1.96km WNW of Dublin, CA · 1717 days ago · 8 km deep · 7 km away · felt by 2
- 1.61km NE of Byron, CA · 1715 days ago · 4 km deep · 31 km away
- 1.51km SE of Pacifica, CA · 1715 days ago · 8 km deep · 49 km away
- 1.52km NNW of Green Valley, CA · 1714 days ago · 6 km deep · 57 km away
- 1.612km SW of Mountain House, CA · 1714 days ago · 18 km deep · 32 km away
- 1.512km SW of Mountain House, CA · 1714 days ago · 18 km deep · 32 km away
- 1.93km WSW of American Canyon, CA · 1713 days ago · 7 km deep · 50 km away
- 1.610km NNE of Morgan Hill, CA · 1712 days ago · 3 km deep · 72 km away · felt by 1
- 1.916km E of Seven Trees, CA · 1711 days ago · 4 km deep · 61 km away
- 2.06km SW of Gilroy, CA · 1706 days ago · 4 km deep · 96 km away · felt by 4
Before
- 1.74km S of Portola Valley, CA · 1767 days ago · 6 km deep · 54 km away · felt by 1
- 1.74km S of Portola Valley, CA · 1767 days ago · 6 km deep · 54 km away
- 2.79km ENE of Morgan Hill, CA · 1770 days ago · 2 km deep · 78 km away · felt by 38
- 2.01km W of Kensington, CA · 1770 days ago · 5 km deep · 31 km away · felt by 43
- 2.51km W of Kensington, CA · 1770 days ago · 5 km deep · 31 km away · felt by 965
- 1.723km WNW of Bonny Doon, CA · 1772 days ago · 7 km deep · 83 km away
- 1.67km ENE of Kenwood, CA · 1773 days ago · 7 km deep · 84 km away
- 1.97km ESE of Bethel Island, CA · 1779 days ago · 9 km deep · 41 km away
- 2.211km NW of Morgan Hill, CA · 1779 days ago · 6 km deep · 67 km away · felt by 1
- 1.98km SSW of Brentwood, CA · 1779 days ago · 19 km deep · 20 km away · felt by 1
- 2.112km ENE of Morgan Hill, CA · 1779 days ago · 4 km deep · 79 km away
- 1.75km E of Fremont, CA · 1780 days ago · 9 km deep · 28 km away
- 1.78km WSW of Mountain House, CA · 1780 days ago · 0 km deep · 30 km away
- 2.44km S of Dillon Beach, CA · 1780 days ago · 10 km deep · 98 km away
- 1.83km S of Dillon Beach, CA · 1780 days ago · 10 km deep · 99 km away
- 1.91km NE of San Ramon, CA · 1781 days ago · 10 km deep · 0 km away
- 1.71km NE of San Ramon, CA · 1782 days ago · 9 km deep · 0 km away
- 1.81km NE of San Ramon, CA · 1782 days ago · 9 km deep · 0 km away · felt by 3
- 2.72km NE of San Ramon, CA · 1782 days ago · 10 km deep · 1 km away · felt by 88
- 1.62km NE of San Ramon, CA · 1782 days ago · 9 km deep · 1 km away · felt by 2
Earthquakes todayCalifornia earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event nc73659476. Read Mon, Oct 5, 2026, 4:15 AM UTC.