QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3md

1km W of Kensington, CA

· 5.0 km deep · released about 79 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Contra Costa County 30 kmMarin County 43 kmAlameda County 44 kmSolano County 50 kmSan Mateo County 56 kmNapa County 66 kmSan Francisco County 68 kmSonoma County 88 kmSan Joaquin County 89 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
Magnitude
M 2.3 (md)
Depth
5.0 km below the surface
Felt
162 reports · strongest reported intensity IV
Nearest
Contra Costa County, 30 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1773 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 162 people have reported feeling it to USGS.

How big was it?

This earthquake released about 79 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 190,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 130,000× the energy of this one
  3. Around the size people start to feel M 3.0 12× the energy of this one
  4. This earthquake M 2.3 about 79 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.

Where

Epicentre 37.9110, -122.2908. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Contra Costa County, CA 30 km (19 mi) W of here earthquakes near Contra Costa County
Marin County, CA 43 km (27 mi) ESE of here earthquakes near Marin County
Alameda County, CA 44 km (28 mi) NW of here earthquakes near Alameda County
Solano County, CA 50 km (31 mi) SW of here earthquakes near Solano County
San Mateo County, CA 56 km (35 mi) N of here earthquakes near San Mateo County
Napa County, CA 66 km (41 mi) S of here earthquakes near Napa County

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

Aftershocks so far

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

  1. 1.9 3km WSW of American Canyon, CA
  2. 1.5 2km NNW of Green Valley, CA
  3. 1.5 1km SE of Pacifica, CA
  4. 1.9 6km WNW of Dublin, CA
  5. 2.2 5km WNW of Dublin, CA
  6. 1.6 4km N of Lafayette, CA
  7. 1.6 5km N of Lafayette, CA
  8. 1.6 2km NNE of San Ramon, CA
  9. 2.4 6km N of Diablo, CA
  10. 2.1 11km SSW of Brentwood, CA
  11. 1.6 1km NE of San Ramon, CA
  12. 1.5 4km WSW of Colma, CA
  13. 1.7 5km WSW of Pacheco, CA
  14. 1.5 2km NE of Union City, CA
  15. 2.6 2km SW 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.5 on 2019-10-15 — it released about 1,900 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

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