QuakeIndex

Earthquake · reviewed by a seismologist

M 2.0md

10km ENE of Blackhawk, CA

· 4.4 km deep · released about 36 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Contra Costa County 15 kmAlameda County 25 kmSolano County 47 kmSan Joaquin County 48 kmSan Mateo County 70 kmSanta Clara County 71 kmSacramento County 78 kmStanislaus County 78 kmMarin County 85 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 2.0 (md)
Depth
4.4 km below the surface
Felt
no reports yet
Nearest
Contra Costa County, 15 km WNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2774 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 36 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.0 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 420,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 300,000× the energy of this one
  3. Around the size people start to feel M 3.0 27× the energy of this one
  4. This earthquake M 2.0 about 36 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 37.8538, -121.8050. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Contra Costa County, CA 15 km (9 mi) ESE of here earthquakes near Contra Costa County
Alameda County, CA 25 km (15 mi) NNE of here earthquakes near Alameda County
Solano County, CA 47 km (29 mi) SSE of here earthquakes near Solano County
San Joaquin County, CA 48 km (30 mi) W of here earthquakes near San Joaquin County
San Mateo County, CA 70 km (43 mi) NE of here earthquakes near San Mateo County
Santa Clara County, CA 71 km (44 mi) N 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

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

  1. 1.5 3km ESE of Berkeley, CA
  2. 2.4 8km NE of Alum Rock, CA
  3. 1.9 2km SSE of Crockett, CA
  4. 1.8 2km ENE of Pleasant Hill, CA
  5. 1.9 2km NNW of Crockett, CA
  6. 2.1 2km WNW of Vallejo, CA
  7. 2.1 4km WNW of Mountain House, CA
  8. 3.0 6km WNW of Mountain House, CA
  9. 1.6 8km NNW of Bay Point, CA
  10. 1.5 8km NNW of Bay Point, CA
  11. 2.1 4km ENE of Oakland, CA
  12. 1.8 8km NE of Alum Rock, CA
  13. 2.1 10km NW of Rio Vista, CA
  14. 1.8 10km ENE of Milpitas, CA
  15. 1.6 8km NE 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 4.4 on 2018-01-04 — it released about 3,100 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.