QuakeIndex

Earthquake · reviewed by a seismologist

M 3.0ml

6km WNW of Mountain House, CA

· 3.7 km deep · released about 920 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Alameda County 32 kmSan Joaquin County 33 kmContra Costa County 33 kmStanislaus County 59 kmSolano County 60 kmSanta Clara County 65 kmSacramento County 76 kmSan Mateo County 80 kmSanta Cruz County 94 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 3.0 (ml)
Depth
3.7 km below the surface
Felt
70 reports · strongest reported intensity IV
Nearest
Alameda County, 32 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2578 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 70 people have reported feeling it to USGS.

How big was it?

This earthquake released about 920 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 370,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 16,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 12,000× the energy of this one
  4. This earthquake M 3.0 about 920 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 37.7978, -121.6053. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Alameda County, CA 32 km (20 mi) ENE of here earthquakes near Alameda County
San Joaquin County, CA 33 km (20 mi) WSW of here earthquakes near San Joaquin County
Contra Costa County, CA 33 km (21 mi) ESE of here earthquakes near Contra Costa County
Stanislaus County, CA 59 km (37 mi) WNW of here earthquakes near Stanislaus County
Solano County, CA 60 km (37 mi) SSE of here earthquakes near Solano County
Santa Clara County, CA 65 km (40 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

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

  1. 1.8 4km NNE of Dublin, CA
  2. 1.6 4km NNE of Dublin, CA
  3. 2.6 4km NNE of Dublin, CA
  4. 1.6 3km SW of Clayton, CA
  5. 1.6 4km N of Dublin, CA
  6. 1.6 4km NNE of Dublin, CA
  7. 1.6 4km NNE of Dublin, CA
  8. 2.0 4km N of Dublin, CA
  9. 1.9 4km N of Dublin, CA
  10. 1.8 4km NNE of Dublin, CA
  11. 1.7 4km N of Dublin, CA
  12. 2.0 4km N of Dublin, CA
  13. 1.6 4km N of Dublin, CA
  14. 2.0 4km NNE of Dublin, CA
  15. 2.3 4km N of Dublin, 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.