QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5md

Earthquake near Kensington, CA

No earthquake was likely felt in Kensington in the 24 hours to 11:57 am PST (19:57 UTC). The last one was M 2.6, 6 km (4 mi) SSE, at 6:23 pm PST on 1 November 2026, estimated intensity III (weak) in town; 114 felt reports to USGS. Every earthquake near Kensington

This page: a magnitude 1.5 earthquake was recorded in Kensington, CA, at 11:33 pm PST on 23 February 2023 (07:33 UTC), 6.0 km deep. 6 people have reported feeling it to USGS.

USGS: 0km W of Kensington, CA

19 km (12 mi) NE of San Francisco, CA · 5 km (3 mi) NNE of Berkeley, CA

11:33 pm PST, Feb 23, 2023 · · 6.0 km deep · released about 5.7 lb of TNT

Every earthquake near Kensington 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
11:33 pm PST on 23 February 2023 ()
Where
in Kensington, CA · earthquakes near Kensington
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
Nearest mapped fault
Hayward fault, 5 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1354 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 8 km (5 mi) from the epicentre. Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

Likely felt in: El Cerrito 2 km, intensity II · Berkeley 4 km, intensity II · Richmond 6 km, intensity II · San Pablo 8 km, intensity II. Estimated for each town centre; each link is that town's own record.

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.

For this area

The largest earthquake within 50 km since 2016 was M 4.5 on 2019-10-15 — about 26,000 times the energy of this one.

Before 2016, the USGS record lists 5 earthquakes of M5 or more within 50 km:

  1. 7.9 The 1906 San Francisco, California Earthquake · 29 km SW of this epicentre
  2. 6.0 The 2014 South Napa, California Earthquake · 34 km N of this epicentre
  3. 5.8 The 1980 Livermore, California Earthquake · 46 km E of this epicentre
  4. 5.3 The 1957 San Francisco, California Earthquake · 32 km SSW of this epicentre
  5. 5.1 11 km E of Blackhawk, California · 46 km ESE of this epicentre

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 37.9107, -122.2858. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Contra Costa County, CA 29 km (18 mi) E earthquakes near Contra Costa County
Marin County, CA 43 km (27 mi) WNW earthquakes near Marin County
Alameda County, CA 44 km (27 mi) SE earthquakes near Alameda County
Solano County, CA 50 km (31 mi) NE earthquakes near Solano County
San Mateo County, CA 56 km (35 mi) S earthquakes near San Mateo County
Napa County, CA 66 km (41 mi) N 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.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.