QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6md

4 km NNW of Union City, California

· 2.0 km deep · released about 7.1 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Alameda County 12 kmContra Costa County 33 kmSan Mateo County 38 kmSanta Clara County 55 kmSanta Cruz County 69 kmSolano County 71 kmSan Joaquin County 76 kmMarin County 77 kmSan Francisco 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 1.6 (md)
Depth
2.0 km below the surface
Felt
no reports yet
Nearest
Alameda County, 12 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3370 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 7.1 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 2,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,500,000× the energy of this one
  3. Around the size people start to feel M 3.0 130× the energy of this one
  4. This earthquake M 1.6 about 7.1 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 37.6335, -122.0428. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Alameda County, CA 12 km (7 mi) W of here earthquakes near Alameda County
Contra Costa County, CA 33 km (20 mi) SSW of here earthquakes near Contra Costa County
San Mateo County, CA 38 km (24 mi) NE of here earthquakes near San Mateo County
Santa Clara County, CA 55 km (34 mi) NW of here earthquakes near Santa Clara County
Santa Cruz County, CA 69 km (43 mi) N of here earthquakes near Santa Cruz County
Solano County, CA 71 km (44 mi) S of here earthquakes near Solano County

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

Aftershocks so far

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

  1. 3.3 3 km NNE of East Foothills, California
  2. 1.8 4 km N of East Foothills, California
  3. 1.7 3 km NNE of Danville, California
  4. 2.6 3 km N of East Foothills, California
  5. 3.3 3 km N of East Foothills, California
  6. 2.0 2 km ESE of Blackhawk, California
  7. 1.9 10 km NE of Milpitas, California
  8. 2.1 1 km ESE of Diablo, California
  9. 2.0 2 km SW of Alamo, California
  10. 1.6 2 km S of Loyola, California
  11. 2.1 4 km E of Union City, California
  12. 2.5 4 km N of East Foothills, California
  13. 1.9 Northern California
  14. 1.8 2 km NNE of North Gate, California
  15. 1.6 0 km ENE of North Gate, 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.