QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

1 km ESE of Diablo, California

· 7.3 km deep · released about 43 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Contra Costa County 10 kmAlameda County 21 kmSolano County 48 kmSan Joaquin County 60 kmSan Mateo County 60 kmSanta Clara County 71 kmMarin County 75 kmNapa County 82 kmSacramento County 86 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 2.1 (md)
Depth
7.3 km below the surface
Felt
6 reports · strongest reported intensity II
Nearest
Contra Costa County, 10 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1512 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 6 people have reported feeling it to USGS.

How big was it?

This earthquake released about 43 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 350,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 250,000× the energy of this one
  3. Around the size people start to feel M 3.0 22× the energy of this one
  4. This earthquake M 2.1 about 43 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 37.8313, -121.9380. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Contra Costa County, CA 10 km (6 mi) S of here earthquakes near Contra Costa County
Alameda County, CA 21 km (13 mi) N of here earthquakes near Alameda County
Solano County, CA 48 km (30 mi) S of here earthquakes near Solano County
San Joaquin County, CA 60 km (37 mi) W of here earthquakes near San Joaquin County
San Mateo County, CA 60 km (37 mi) NE of here earthquakes near San Mateo County
Santa Clara County, CA 71 km (44 mi) NNW of here earthquakes near Santa Clara County

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

Aftershocks so far

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

  1. 1.6 13km SSE of Livermore, CA
  2. 2.1 2km ENE of Berkeley, CA
  3. 1.6 2km E of Diablo, CA
  4. 1.6 6km ENE of Dublin, CA
  5. 1.8 10km SSE of Elmira, CA
  6. 2.4 10km S of Elmira, CA
  7. 2.0 9km ENE of Milpitas, CA
  8. 2.6 2km NNE of San Leandro, CA
  9. 1.7 5km NNE of San Leandro, CA
  10. 2.4 1km E of Pacheco, CA
  11. 1.7 1 km N of North Fair Oaks, California
  12. 2.1 3 km SSE of Rio Vista, California
  13. 2.0 10 km ENE of Milpitas, California
  14. 1.6 2 km NNW of Pleasant Hill, California
  15. 2.7 6km SE of Rio Vista, 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.