Earthquake · reviewed by a seismologist
M 1.8md
Earthquake near Bolinas, CA
No earthquake was likely felt in Bolinas in the 24 hours to 4:09 am PST (12:09 UTC). The last one was M 3.8, 50 km (31 mi) ESE, at 8:30 am PDT on 13 August 2026, estimated intensity II (weak) in town; 7,876 felt reports to USGS. Every earthquake near Bolinas
This page: a magnitude 1.8 earthquake was recorded 14 km (9 mi) south of Bolinas, CA, at 6:32 am PST on 2 January 2020 (14:32 UTC), 7.2 km deep. 1 person has reported feeling it to USGS.
USGS: 14km S of Bolinas, CA
25 km (16 mi) W of San Francisco, CA · 23 km (14 mi) WNW of Daly City, CA
- When
- 6:32 am PST on 2 January 2020 ()
- Where
- 14 km (9 mi) south of Bolinas, CA · earthquakes near Bolinas
- Magnitude
- M 1.8 (md)
- Depth
- 7.2 km below the surface
- Felt
- 1 report · strongest reported intensity III
- Nearest
- San Francisco County, 29 km WSW
- Nearest mapped fault
- San Gregorio fault, 1 km from its surface trace — near is not the same as on
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 2495 days ago
Earthquake alerts for Bolinas, CA
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Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
At this magnitude and depth, people at rest would likely notice it out to about 11 km (7 mi) from the epicentre. In Bolinas, 14 km away, the estimate is intensity II (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.
Earthquakes near other towns within 30 km: Tamalpais Valley, Tamalpais-Homestead Valley, Mill Valley, Marin City, Sausalito, Strawberry.
How big was it?
This earthquake released about 14 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 1,100,000× the energy of this one
- Magna, Utah 2020 M 5.7 790,000× the energy of this one
- Around the size people start to feel M 3.0 70× the energy of this one
- This earthquake M 1.8 about 14 lb of TNT
Energy from the Gutenberg–Richter relation (log10E = 1.5M + 4.8), rounded to two figures; bar length is magnitude, which is already a logarithm of energy. Magnitudes of past earthquakes from the USGS catalogue.
For this area
The largest earthquake within 50 km since 2016 was M 4.4 on 2018-01-04 — about 8,200 times the energy of this one.
Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:
- 7.9 The 1906 San Francisco, California Earthquake · 14 km ESE of this epicentre
- 5.3 The 1957 San Francisco, California Earthquake · 24 km SE of this epicentre
Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.
Where
Epicentre 37.7855, -122.7052. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| San Francisco County, CA | 29 km (18 mi) | WSW | earthquakes near San Francisco County |
| Marin County, CA | 30 km (19 mi) | N | earthquakes near Marin County |
| San Mateo County, CA | 51 km (31 mi) | SE | earthquakes near San Mateo County |
| Contra Costa County, CA | 68 km (42 mi) | ENE | earthquakes near Contra Costa County |
| Alameda County, CA | 71 km (44 mi) | ESE | earthquakes near Alameda County |
| Sonoma County, CA | 84 km (52 mi) | NNW | earthquakes near Sonoma County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
36 earthquakes have been recorded within 50 km since this one.
- 2.0 2km NNW of Kensington, CA
- 3.3 7km S of Muir Beach, CA
- 2.6 0km E of San Pablo, CA
- 1.7 2km E of Berkeley, CA
- 2.5 0km SE of Rollingwood, CA
- 1.6 0km SE of Rollingwood, CA
- 1.6 2km N of El Cerrito, CA
- 1.8 3km ESE of Berkeley, CA
- 1.6 6km W of San Francisco Zoo, CA
- 1.6 3km ESE of Highlands-Baywood Park, CA
- 1.6 6km ESE of Santa Venetia, CA
- 1.8 5km NNE of Black Point-Green Point, CA
- 2.4 2km E of Berkeley, CA
- 2.6 4km ESE of Berkeley, CA
- 2.1 4km ESE of Berkeley, CA
Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of . QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.
On USGS
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.