QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

1km S of Kensington, CA

· 4.5 km deep · released about 12 lb of TNT

10 km30 km60 km120 km N Contra Costa County 29 kmAlameda County 43 kmMarin County 44 kmSolano County 51 kmSan Mateo County 54 kmNapa County 68 kmSan Francisco County 69 kmSan Joaquin County 89 kmSonoma County 90 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 1.7 (md)
Depth
4.5 km below the surface
Felt
33 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 2305 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 33 people have reported feeling it to USGS.

How big was it?

This earthquake released about 12 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,200,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 870,000× the energy of this one
  3. Around the size people start to feel M 3.0 78× the energy of this one
  4. This earthquake M 1.7 about 12 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 37.8988, -122.2813. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Contra Costa County, CA 29 km (18 mi) W of here earthquakes near Contra Costa County
Alameda County, CA 43 km (27 mi) NW of here earthquakes near Alameda County
Marin County, CA 44 km (27 mi) ESE of here earthquakes near Marin County
Solano County, CA 51 km (32 mi) SW of here earthquakes near Solano County
San Mateo County, CA 54 km (34 mi) N of here earthquakes near San Mateo County
Napa County, CA 68 km (42 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

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

  1. 1.7 1km SW of Diablo, CA
  2. 1.6 3km SW of Clayton, CA
  3. 1.5 6km NW of Pacifica, CA
  4. 1.6 3km ENE of Oakland, CA
  5. 2.2 3km ENE of Walnut Creek, CA
  6. 3.2 3km ESE of San Leandro, CA
  7. 2.6 3km ESE of San Leandro, CA
  8. 1.8 2km N of Danville, CA
  9. 2.7 2km SSE of Crockett, CA
  10. 2.3 2km NE of El Cerrito, CA
  11. 1.6 4km SSW of Newark, CA
  12. 2.6 6km SW of Clayton, CA
  13. 2.5 6km NE of Alamo, CA
  14. 1.6 5km E of Vallejo, CA
  15. 1.9 6km NE of Alamo, 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 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.