QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3md

3km WSW of Muir Beach, CA

· 4.3 km deep · released about 85 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Marin County 25 kmSan Francisco County 40 kmSan Mateo County 53 kmContra Costa County 58 kmAlameda County 65 kmSolano County 75 kmNapa County 77 kmSonoma County 80 kmSanta Clara County 107 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
4.3 km below the surface
Felt
no reports yet
Nearest
Marin County, 25 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3081 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

How big was it?

This earthquake released about 85 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 5.8 180,000× 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 11× the energy of this one
  4. This earthquake M 2.3 about 85 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 37.8510, -122.6070. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Marin County, CA 25 km (16 mi) SSE of here earthquakes near Marin County
San Francisco County, CA 40 km (25 mi) ENE of here earthquakes near San Francisco County
San Mateo County, CA 53 km (33 mi) NNW of here earthquakes near San Mateo County
Contra Costa County, CA 58 km (36 mi) W of here earthquakes near Contra Costa County
Alameda County, CA 65 km (40 mi) WNW of here earthquakes near Alameda County
Solano County, CA 75 km (46 mi) SW of here earthquakes near Solano County

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

Aftershocks so far

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

  1. 1.8 0km W of Crockett, CA
  2. 2.0 3km ESE of Berkeley, CA
  3. 2.0 2km W of Orinda, CA
  4. 2.3 1km NNW of San Pablo, CA
  5. 1.7 1km E of Pacheco, CA
  6. 2.0 3km ENE of San Leandro, CA
  7. 1.8 4km SSE of Point Reyes Station, CA
  8. 1.6 8km SW of Napa, CA
  9. 2.5 1km WNW of Crockett, CA
  10. 1.6 1km E of San Leandro, CA
  11. 2.3 3km ENE of Oakland, CA
  12. 1.6 1km ESE of East Richmond Heights, CA
  13. 2.5 3km ENE of Oakland, CA
  14. 1.7 2km NNW of Crockett, CA
  15. 2.4 1km NW of Crockett, 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 4.4 on 2018-01-04 — it released about 1,300 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.