QuakeIndex

Earthquake · reviewed by a seismologist

M 2.2md

Earthquake near Pacifica, CA

No earthquake was likely felt in Pacifica in the 24 hours to 1:25 am PST (09:25 UTC). The last one was M 2.7, 2 km (1 mi) NE, at 5:17 pm PDT on 28 October 2026, estimated intensity III (weak) in town; 526 felt reports to USGS. Every earthquake near Pacifica

This page: a magnitude 2.2 earthquake was recorded in Pacifica, CA, at 7:09 am PDT on 13 July 2022 (14:09 UTC), 8.8 km deep. 41 people have reported feeling it to USGS.

USGS: 1km WSW of Pacifica, CA

20 km (12 mi) SSW of San Francisco, CA · 11 km (7 mi) SSW of Daly City, CA

7:09 am PDT, Jul 13, 2022 · · 8.8 km deep · released about 64 lb of TNT

10 km30 km60 km120 km N San Mateo County 25 kmSan Francisco County 48 kmAlameda County 52 kmMarin County 53 kmContra Costa County 59 kmSanta Cruz County 80 kmSanta Clara County 84 kmSolano County 88 kmNapa County 101 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
7:09 am PDT on 13 July 2022 ()
Where
in Pacifica, CA · earthquakes near Pacifica
Magnitude
M 2.2 (md)
Depth
8.8 km below the surface
Felt
41 reports · strongest reported intensity III
Nearest
San Mateo County, 25 km SSE
Nearest mapped fault
San Andreas 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 1581 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 17 km (11 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: Pacifica in town, intensity II · San Bruno 8 km, intensity II · South San Francisco 10 km, intensity II · Millbrae 10 km, intensity II · Daly City 11 km, intensity II · Burlingame 12 km, intensity II · San Mateo 16 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 64 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.2 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 230,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 170,000× the energy of this one
  3. Around the size people start to feel M 3.0 15× the energy of this one
  4. This earthquake M 2.2 about 64 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 1,700 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 · 16 km NNW of this epicentre
  2. 5.3 The 1957 San Francisco, California Earthquake · 6 km NNE 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 37.6108, -122.5020. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Mateo County, CA 25 km (15 mi) SSE earthquakes near San Mateo County
San Francisco County, CA 48 km (30 mi) WNW earthquakes near San Francisco County
Alameda County, CA 52 km (32 mi) E earthquakes near Alameda County
Marin County, CA 53 km (33 mi) NNW earthquakes near Marin County
Contra Costa County, CA 59 km (37 mi) NE earthquakes near Contra Costa County
Santa Cruz County, CA 80 km (49 mi) SSE earthquakes near Santa Cruz County

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

Aftershocks so far

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

  1. 1.8 6km SSE of Portola Valley, CA
  2. 2.0 6km SSE of Portola Valley, CA
  3. 2.1 6km SSE of Portola Valley, CA
  4. 1.9 6km SSE of Portola Valley, CA
  5. 1.7 6km SSE of Portola Valley, CA
  6. 1.5 14km WSW of Portola Valley, CA
  7. 1.7 6km NNW of Lafayette, CA
  8. 2.6 7km SSW of Muir Beach, CA
  9. 1.6 7km ESE of Santa Venetia, CA
  10. 1.8 2km NNW of Oakland, CA
  11. 1.8 6km SSE of Portola Valley, CA
  12. 1.9 6km SSE of Portola Valley, CA
  13. 2.1 2km NNE of San Leandro, CA
  14. 1.7 4km WNW of Dublin, CA
  15. 2.6 4km WSW of Colma, 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.