QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3md

1 km E of Pacheco, California

· 17 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 kmSolano County 33 kmAlameda County 40 kmMarin County 61 kmNapa County 63 kmSan Mateo County 69 kmSan Joaquin County 69 kmYolo County 79 kmSacramento County 81 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
17 km below the surface
Felt
no reports yet
Nearest
Contra Costa County, 12 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3236 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 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 37.9840, -122.0585. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Contra Costa County, CA 12 km (7 mi) NW of here earthquakes near Contra Costa County
Solano County, CA 33 km (21 mi) SSW of here earthquakes near Solano County
Alameda County, CA 40 km (25 mi) NNW of here earthquakes near Alameda County
Marin County, CA 61 km (38 mi) E of here earthquakes near Marin County
Napa County, CA 63 km (39 mi) SSE of here earthquakes near Napa County
San Mateo County, CA 69 km (43 mi) NNE of here earthquakes near San Mateo County

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

Aftershocks so far

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

  1. 2.8 2km NW of Diablo, CA
  2. 2.4 2km WNW of Diablo, CA
  3. 1.6 2km WNW of Diablo, CA
  4. 3.0 2km WNW of Diablo, CA
  5. 1.8 2km WNW of Diablo, CA
  6. 2.5 2km WNW of Diablo, CA
  7. 2.2 2km WNW of Diablo, CA
  8. 1.7 2km W of Diablo, CA
  9. 1.5 2km W of Diablo, CA
  10. 2.1 2km WNW of Diablo, CA
  11. 1.5 2km W of Diablo, CA
  12. 2.1 2km WNW of Diablo, CA
  13. 1.5 2km WNW of Diablo, CA
  14. 2.4 2km WNW of Diablo, CA
  15. 1.9 2km WNW of Diablo, 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.