QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3md

1 km W of Danville, California

· 10 km deep · released about 94 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Contra Costa County 12 kmAlameda County 22 kmSolano County 50 kmSan Mateo County 55 kmSan Joaquin County 67 kmMarin County 69 kmSanta Clara County 73 kmNapa County 81 kmSan Francisco County 90 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
10 km below the surface
Felt
18 reports · strongest reported intensity III
Nearest
Contra Costa County, 12 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3397 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 18 people have reported feeling it to USGS.

How big was it?

This earthquake released about 94 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 5.8 160,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 110,000× the energy of this one
  3. Around the size people start to feel M 3.0 10× the energy of this one
  4. This earthquake M 2.3 about 94 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 37.8242, -122.0195. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Contra Costa County, CA 12 km (8 mi) SSW of here earthquakes near Contra Costa County
Alameda County, CA 22 km (14 mi) NNW of here earthquakes near Alameda County
Solano County, CA 50 km (31 mi) S of here earthquakes near Solano County
San Mateo County, CA 55 km (34 mi) NE of here earthquakes near San Mateo County
San Joaquin County, CA 67 km (41 mi) W of here earthquakes near San Joaquin County
Marin County, CA 69 km (43 mi) ESE of here earthquakes near Marin County

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

Aftershocks so far

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

  1. 3.3 3 km NNE of East Foothills, California
  2. 1.8 4 km N of East Foothills, California
  3. 1.7 3 km NNE of Danville, California
  4. 2.6 3 km N of East Foothills, California
  5. 3.3 3 km N of East Foothills, California
  6. 2.0 2 km ESE of Blackhawk, California
  7. 1.9 10 km NE of Milpitas, California
  8. 2.1 1 km ESE of Diablo, California
  9. 2.0 2 km SW of Alamo, California
  10. 2.1 4 km E of Union City, California
  11. 2.5 4 km N of East Foothills, California
  12. 1.8 2 km NNE of North Gate, California
  13. 1.6 0 km ENE of North Gate, California
  14. 2.5 1 km N of Pleasant Hill, California
  15. 1.8 1 km NNW of Pleasant Hill, California

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.