QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5md

0km W of Kensington, CA

· 6.0 km deep · released about 5.7 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Contra Costa County 29 kmMarin County 43 kmAlameda County 44 kmSolano County 50 kmSan Mateo County 56 kmNapa County 66 kmSan Francisco County 69 kmSonoma County 88 kmSan Joaquin County 89 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 1.5 (md)
Depth
6.0 km below the surface
Felt
6 reports · strongest reported intensity II
Nearest
Contra Costa County, 29 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1307 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 6 people have reported feeling it to USGS.

How big was it?

This earthquake released about 5.7 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,600,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,900,000× the energy of this one
  3. Around the size people start to feel M 3.0 170× the energy of this one
  4. This earthquake M 1.5 about 5.7 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 37.9107, -122.2858. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Contra Costa County, CA 29 km (18 mi) W of here earthquakes near Contra Costa County
Marin County, CA 43 km (27 mi) ESE of here earthquakes near Marin County
Alameda County, CA 44 km (27 mi) NW of here earthquakes near Alameda County
Solano County, CA 50 km (31 mi) SW of here earthquakes near Solano County
San Mateo County, CA 56 km (35 mi) N of here earthquakes near San Mateo County
Napa County, CA 66 km (41 mi) S of here earthquakes near Napa County

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

Aftershocks so far

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

  1. 2.1 6km NNE of San Leandro, CA
  2. 2.2 6km SSW of Antioch, CA
  3. 1.9 1km SSE of Diablo, CA
  4. 1.6 4km NNW of Diablo, CA
  5. 1.6 3km N of Danville, CA
  6. 1.6 2km E of Union City, CA
  7. 2.2 2km ENE of Union City, CA
  8. 1.5 8km SSW of Antioch, CA
  9. 1.6 2km S of Blackhawk, CA
  10. 2.0 2km S of Blackhawk, CA
  11. 1.8 2km S of Blackhawk, CA
  12. 2.0 2km S of Blackhawk, CA
  13. 1.8 6km E of San Rafael, CA
  14. 1.7 2km S of San Ramon, CA
  15. 1.9 6km SW of Antioch, 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 4.5 on 2019-10-15 — it released about 26,000 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.