QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

Earthquake near San Francisco, CA

No earthquake was likely felt in San Francisco in the 24 hours to 5:28 am PST (13:28 UTC). The last one was M 2.6, 18 km (11 mi) ENE, at 6:23 pm PST on 1 November 2026, estimated intensity II (weak) in town; 114 felt reports to USGS. Every earthquake near San Francisco

This page: a magnitude 2.1 earthquake was recorded 14 km (9 mi) west-southwest of San Francisco, CA, at 4:52 pm PST on 24 January 2019 (00:52 UTC), 8.1 km deep.

USGS: 5km WSW of San Francisco Zoo, CA

14 km (9 mi) WSW of San Francisco, CA · 8 km (5 mi) W of Daly City, CA

4:52 pm PST, Jan 24, 2019 · · 8.1 km deep · released about 40 lb of TNT

10 km30 km60 km120 km N San Mateo County 37 kmMarin County 41 kmSan Francisco County 42 kmAlameda County 57 kmContra Costa County 58 kmSolano County 82 kmNapa County 90 kmSanta Cruz County 92 kmSanta Clara County 94 km
Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.
When
4:52 pm PST on 24 January 2019 ()
Where
14 km (9 mi) west-southwest of San Francisco, CA · earthquakes near San Francisco
Magnitude
M 2.1 (md)
Depth
8.1 km below the surface
Felt
no reports yet
Nearest
San Mateo County, 37 km SSE
Nearest mapped fault
San Andreas fault, 2 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 2821 days ago

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 15 km (9 mi) from the epicentre. In San Francisco, 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.

Likely felt in: Daly City 8 km, intensity II · Pacifica 13 km, intensity II · San Francisco 14 km, intensity II · South San Francisco 15 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 40 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 380,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 270,000× the energy of this one
  3. Around the size people start to feel M 3.0 24× the energy of this one
  4. This earthquake M 2.1 about 40 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 2,800 times the energy of this one.

Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:

  1. 7.9 The 1906 San Francisco, California Earthquake · 4 km N of this epicentre
  2. 5.3 The 1957 San Francisco, California Earthquake · 8 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 37.7147, -122.5575. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Mateo County, CA 37 km (23 mi) SSE earthquakes near San Mateo County
Marin County, CA 41 km (25 mi) NNW earthquakes near Marin County
San Francisco County, CA 42 km (26 mi) W earthquakes near San Francisco County
Alameda County, CA 57 km (36 mi) E earthquakes near Alameda County
Contra Costa County, CA 58 km (36 mi) ENE earthquakes near Contra Costa County
Solano County, CA 82 km (51 mi) NE earthquakes near Solano County

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

42 earthquakes have been recorded within 50 km since this one.

  1. 1.5 3km ESE of Berkeley, CA
  2. 2.1 2km NNE of Pacifica, CA
  3. 1.9 2km SSE of Crockett, CA
  4. 1.6 4km NNW of Pacifica, CA
  5. 1.9 2km NNW of Crockett, CA
  6. 2.4 2km NNE of Pacifica, CA
  7. 2.1 4km ENE of Oakland, CA
  8. 1.5 8km S of Muir Beach, CA
  9. 1.8 3km WSW of Muir Beach, CA
  10. 1.9 2km NW of Crockett, CA
  11. 1.6 2km S of Alamo, CA
  12. 2.2 3km ESE of Berkeley, CA
  13. 1.9 4km SE of Rodeo, CA
  14. 1.7 1km N of East Richmond Heights, CA
  15. 2.0 5km N of San Leandro, 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

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.