QuakeIndex

Earthquake · reviewed by a seismologist

M 2.9md

5 km WNW of Dublin, CA

· 10 km deep · released about 780 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Alameda County 10 kmContra Costa County 24 kmSan Mateo County 46 kmSanta Clara County 60 kmSolano County 63 kmSan Joaquin County 68 kmMarin County 76 kmSanta Cruz County 77 kmStanislaus County 89 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 2.9 (md)
Depth
10 km below the surface
Felt
366 reports · strongest reported intensity IV
Nearest
Alameda County, 10 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 370 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 366 people have reported feeling it to USGS.

How big was it?

This earthquake released about 780 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 19,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 14,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.2× the energy of this one
  4. This earthquake M 2.9 about 780 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 37.7048, -121.9937. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Alameda County, CA 10 km (6 mi) NW of here earthquakes near Alameda County
Contra Costa County, CA 24 km (15 mi) S of here earthquakes near Contra Costa County
San Mateo County, CA 46 km (29 mi) NE of here earthquakes near San Mateo County
Santa Clara County, CA 60 km (37 mi) NNW of here earthquakes near Santa Clara County
Solano County, CA 63 km (39 mi) S of here earthquakes near Solano County
San Joaquin County, CA 68 km (42 mi) WSW of here earthquakes near San Joaquin County

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

Aftershocks so far

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

  1. 2.1 4 km SE of Rodeo, CA
  2. 1.6 3 km SE of Rodeo, CA
  3. 3.2 2 km NW of Pinole, CA
  4. 1.5 3 km WSW of San Ramon, CA
  5. 1.7 2 km SSE of Danville, CA
  6. 1.8 1 km WSW of Concord, CA
  7. 1.9 2 km ESE of Piedmont, CA
  8. 1.5 1 km E of Union City, CA
  9. 1.9 1 km NE of Rodeo, CA
  10. 1.7 8 km NE of Alum Rock, CA
  11. 2.5 3 km of Piedmont, CA
  12. 1.5 3 km N of Piedmont, CA
  13. 2.3 3 km of Piedmont, CA
  14. 1.8 11 km NNE of Pittsburg, CA
  15. 2.1 11 km of Pittsburg, 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 190 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.