QuakeIndex

Earthquake · reviewed by a seismologist

M 2.6mh

Earthquake near Colma, CA

No earthquake was likely felt in Colma in the 24 hours to 7:14 am PST (15:14 UTC). The last one was M 2.7, 6 km (4 mi) S, at 5:17 pm PDT on 28 October 2026, estimated intensity III (weak) in town; 526 felt reports to USGS. Every earthquake near Colma

This page: a magnitude 2.6 earthquake was recorded in Colma, CA, at 3:18 am PST on 4 January 2022 (11:18 UTC), 8.0 km deep.

USGS: 2km SW of Colma, CA

14 km (8 mi) SSW of San Francisco, CA · in Daly City, CA

3:18 am PST, Jan 4, 2022 · · 8.0 km deep · released about 240 lb of TNT

10 km30 km60 km120 km N San Mateo County 29 kmAlameda County 49 kmMarin County 49 kmSan Francisco County 50 kmContra Costa County 54 kmSolano County 82 kmSanta Cruz County 83 kmSanta Clara County 85 kmNapa County 95 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
3:18 am PST on 4 January 2022 ()
Where
in Colma, CA · earthquakes near Colma
Magnitude
M 2.6 (mh)
Depth
8.0 km below the surface
Felt
no reports yet
Nearest
San Mateo County, 29 km SSE
Nearest mapped fault
Serra fault, under 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 1766 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 22 km (14 mi) from the epicentre. 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 5 km, intensity III · South San Francisco 6 km, intensity III · Pacifica 6 km, intensity III · San Bruno 6 km, intensity III · Millbrae 10 km, intensity II · Bayview-Hunters Point 11 km, intensity II · Burlingame 13 km, intensity II · San Francisco 13 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 240 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 63,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 45,000× the energy of this one
  3. Around the size people start to feel M 3.0 4× the energy of this one
  4. This earthquake M 2.6 about 240 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 4.5 on 2019-10-15 — about 620 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 · 12 km NW of this epicentre
  2. 5.3 The 1957 San Francisco, California Earthquake · 1 km WNW 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 37.6643, -122.4705. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Mateo County, CA 29 km (18 mi) SSE earthquakes near San Mateo County
Alameda County, CA 49 km (31 mi) E earthquakes near Alameda County
Marin County, CA 49 km (31 mi) NNW earthquakes near Marin County
San Francisco County, CA 50 km (31 mi) W earthquakes near San Francisco County
Contra Costa County, CA 54 km (33 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

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

  1. 1.8 2km SE of Danville, CA
  2. 2.1 1km E of Piedmont, CA
  3. 1.8 3km NNE of San Ramon, CA
  4. 1.7 3km S of Diablo, CA
  5. 2.0 4km SSE of Highlands-Baywood Park, CA
  6. 1.9 2km N of Castro Valley, CA
  7. 1.9 5km ESE of Moraga, CA
  8. 1.6 4km SW of San Ramon, CA
  9. 1.6 4km SW of San Ramon, CA
  10. 1.6 2km E of Pleasant Hill, CA
  11. 1.6 5km E of Fremont, CA
  12. 1.6 7km S of Muir Beach, CA
  13. 1.8 3km SW of San Francisco Zoo, CA
  14. 2.2 2km NW of Diablo, CA
  15. 2.1 3km NE 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

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