QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9md

6 km W of Country Club, California

· 22 km deep · released about 21 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N San Joaquin County 13 kmContra Costa County 48 kmSacramento County 53 kmSolano County 57 kmAlameda County 57 kmStanislaus County 58 kmCalaveras County 78 kmAmador County 84 kmSanta Clara County 88 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 1.9 (md)
Depth
22 km below the surface
Felt
no reports yet
Nearest
San Joaquin County, 13 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3474 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 21 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 710,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 500,000× the energy of this one
  3. Around the size people start to feel M 3.0 45× the energy of this one
  4. This earthquake M 1.9 about 21 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 37.9772, -121.4088. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
San Joaquin County, CA 13 km (8 mi) WNW of here earthquakes near San Joaquin County
Contra Costa County, CA 48 km (30 mi) E of here earthquakes near Contra Costa County
Sacramento County, CA 53 km (33 mi) S of here earthquakes near Sacramento County
Solano County, CA 57 km (35 mi) SE of here earthquakes near Solano County
Alameda County, CA 57 km (36 mi) NE of here earthquakes near Alameda County
Stanislaus County, CA 58 km (36 mi) NW of here earthquakes near Stanislaus County

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

Aftershocks so far

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

  1. 1.8 13km SE of Livermore, CA
  2. 1.6 2km ENE of Diablo, CA
  3. 2.6 12km WNW of Rio Vista, CA
  4. 1.6 9km SSW of Brentwood, CA
  5. 2.4 8km SSW of Brentwood, CA
  6. 1.8 6km W of French Camp, CA
  7. 1.8 9km E of Livermore, CA
  8. 2.0 12km SSW of Mountain House, CA
  9. 1.5 9km SE of Livermore, CA
  10. 2.0 20km W of Westley, CA
  11. 1.5 8km SSE of Rio Vista, CA
  12. 2.3 2km NW of Pittsburg, CA
  13. 1.6 2km E of Diablo, CA
  14. 1.6 6km ENE of Dublin, CA
  15. 2.1 3 km SSE of Rio Vista, California

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.