QuakeIndex

Earthquake · automatic estimate, may change

M 2.2md

2 km SW of Kentfield, CA

· 16 km deep · released about 56 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Marin County 20 kmSan Francisco County 46 kmContra Costa County 55 kmSan Mateo County 61 kmAlameda County 67 kmSolano County 67 kmNapa County 67 kmSonoma County 72 kmYolo 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
Magnitude
M 2.2 (md)
Depth
16 km below the surface
Felt
8 reports
Nearest
Marin County, 20 km NW
Status
Automatic — a machine’s first estimate, which may change

USGS · last changed by USGS · we first saw it 222 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 8 people have reported feeling it to USGS.

How big was it?

This earthquake released about 56 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 5.8 270,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 190,000× the energy of this one
  3. Around the size people start to feel M 3.0 17× the energy of this one
  4. This earthquake M 2.2 about 56 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 37.9377, -122.5763. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Marin County, CA 20 km (12 mi) SE of here earthquakes near Marin County
San Francisco County, CA 46 km (29 mi) ENE of here earthquakes near San Francisco County
Contra Costa County, CA 55 km (34 mi) W of here earthquakes near Contra Costa County
San Mateo County, CA 61 km (38 mi) NNW of here earthquakes near San Mateo County
Alameda County, CA 67 km (41 mi) WNW of here earthquakes near Alameda County
Solano County, CA 67 km (41 mi) WSW of here earthquakes near Solano County

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

Aftershocks so far

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

  1. 1.6 2 km SE of East Richmond Heights, CA
  2. 1.6 3 km NW of Hercules, CA
  3. 1.7 3 km NW of Hercules, CA
  4. 1.7 2 km SSE of Pacifica, CA
  5. 2.7 2 km ESE of Pinole, CA
  6. 1.8 2 km SE of Pacifica, CA
  7. 1.9 3 km ESE of Berkeley, CA
  8. 1.9 1 km ESE of Pinole, CA
  9. 2.3 2 km SE of Pacifica, CA
  10. 1.7 3 km S of Green Valley, CA
  11. 2.5 1 km ESE of Pinole, CA
  12. 2.3 4 km SW of Green Valley, CA
  13. 2.1 6 km SE of Napa, CA
  14. 1.5 3 km SSW of San Francisco Zoo, CA
  15. 2.6 3 km SSW of San Francisco Zoo, 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 2,600 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.