QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6md

9km SSW of Brentwood, CA

· 19 km deep · released about 9 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Contra Costa County 17 kmAlameda County 26 kmSan Joaquin County 45 kmSolano County 48 kmSanta Clara County 71 kmSan Mateo County 72 kmStanislaus County 76 kmSacramento County 76 kmNapa County 87 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 1.6 (md)
Depth
19 km below the surface
Felt
no reports yet
Nearest
Contra Costa County, 17 km WNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3118 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 9 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,700,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,200,000× the energy of this one
  3. Around the size people start to feel M 3.0 110× the energy of this one
  4. This earthquake M 1.6 about 9 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 37.8553, -121.7792. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Contra Costa County, CA 17 km (10 mi) ESE of here earthquakes near Contra Costa County
Alameda County, CA 26 km (16 mi) NNE of here earthquakes near Alameda County
San Joaquin County, CA 45 km (28 mi) W of here earthquakes near San Joaquin County
Solano County, CA 48 km (30 mi) SSE of here earthquakes near Solano County
Santa Clara County, CA 71 km (44 mi) N of here earthquakes near Santa Clara County
San Mateo County, CA 72 km (44 mi) NE 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

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

  1. 1.6 4km ENE of Oakland, CA
  2. 1.7 4km ESE of Union City, CA
  3. 2.2 3km ENE of Oakland, CA
  4. 2.1 2km ENE of San Ramon, CA
  5. 3.5 3km ENE of Oakland, CA
  6. 1.9 13km SE of Livermore, CA
  7. 1.8 2km ENE of San Ramon, CA
  8. 1.6 2km ENE of San Ramon, CA
  9. 2.0 3km W of Pittsburg, CA
  10. 1.5 1km ENE of Diablo, CA
  11. 2.5 2km ENE of Danville, CA
  12. 2.2 3km ESE of Berkeley, CA
  13. 1.9 9km NNE of Alum Rock, CA
  14. 1.5 13km SE of Livermore, CA
  15. 1.5 2km E of Danville, 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 12,000 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.