QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3md

2 km SSE of Dublin, California

· 9.1 km deep · released about 77 lb of TNT

10 km30 km60 km120 km N Alameda County 4 kmContra Costa County 26 kmSan Mateo County 50 kmSanta Clara County 56 kmSan Joaquin County 64 kmSolano County 65 kmSanta Cruz County 75 kmStanislaus County 82 kmMarin County 83 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
9.1 km below the surface
Felt
4 reports · strongest reported intensity IV
Nearest
Alameda County, 4 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3249 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 4 people have reported feeling it to USGS.

How big was it?

This earthquake released about 77 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 5.8 200,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 140,000× 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 77 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 37.6847, -121.9243. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Alameda County, CA 4 km (3 mi) NNW of here earthquakes near Alameda County
Contra Costa County, CA 26 km (16 mi) S of here earthquakes near Contra Costa County
San Mateo County, CA 50 km (31 mi) NE of here earthquakes near San Mateo County
Santa Clara County, CA 56 km (34 mi) NNW of here earthquakes near Santa Clara County
San Joaquin County, CA 64 km (40 mi) WSW of here earthquakes near San Joaquin County
Solano County, CA 65 km (40 mi) S of here earthquakes near Solano County

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

Aftershocks so far

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

  1. 1.9 2km WNW of Diablo, CA
  2. 2.2 2km WNW of Diablo, CA
  3. 1.9 2km WNW of Diablo, CA
  4. 2.8 2km W of Diablo, CA
  5. 2.2 2km WNW of Diablo, CA
  6. 2.4 2km NNE of El Cerrito, CA
  7. 1.7 6km E of Fremont, CA
  8. 2.0 0km WNW of Pacheco, CA
  9. 1.8 9km ENE of Milpitas, CA
  10. 1.8 9km E of Livermore, CA
  11. 1.6 3km NNE of San Leandro, CA
  12. 2.0 12km SSW of Mountain House, CA
  13. 1.8 3km SE of Oakland, CA
  14. 2.9 16km E of Seven Trees, CA
  15. 1.6 10km NNE of Alum Rock, 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 4.1 on 2017-10-10 — it released about 540 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.