QuakeIndex

Earthquake · reviewed by a seismologist

M 4.2mw

5 km SW of Isleton, CA

· 8.5 km deep · released about 35 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Solano County 30 kmContra Costa County 36 kmSan Joaquin County 39 kmSacramento County 44 kmAlameda County 58 kmYolo County 65 kmNapa County 73 kmStanislaus County 84 kmAmador County 93 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 4.2 (mw)
Depth
8.5 km below the surface
Felt
7899 reports · strongest reported intensity V
Measured shaking
intensity VI (ShakeMap)
USGS impact alert
green
Nearest
Solano County, 30 km WNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 738 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon. 7899 people have reported feeling it to USGS.

How big was it?

This earthquake released about 35 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.2 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 4,900× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 220× the energy of this one
  3. Magna, Utah 2020 M 5.7 150× the energy of this one
  4. This earthquake M 4.2 about 35 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 72× more

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 38.1270, -121.6428. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Solano County, CA 30 km (19 mi) ESE of here earthquakes near Solano County
Contra Costa County, CA 36 km (22 mi) NE of here earthquakes near Contra Costa County
San Joaquin County, CA 39 km (24 mi) WNW of here earthquakes near San Joaquin County
Sacramento County, CA 44 km (28 mi) SW of here earthquakes near Sacramento County
Alameda County, CA 58 km (36 mi) NNE of here earthquakes near Alameda County
Yolo County, CA 65 km (41 mi) SSE of here earthquakes near Yolo County

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

Aftershocks so far

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

  1. 1.5 5 km E of Vallejo, CA
  2. 1.7 3 km E of Alamo, CA
  3. 1.7 5 km E of Vallejo, CA
  4. 1.6 2 km N of Livermore, CA
  5. 1.6 6 km ENE of Vallejo, CA
  6. 1.8 10 km ENE of Blackhawk, CA
  7. 1.8 10 km SSW of Brentwood, CA
  8. 1.5 6 km E of Walnut Creek, CA
  9. 1.7 1 km W of Pacheco, CA
  10. 2.0 10 km ESE of Clayton, CA
  11. 1.9 11 km E of Blackhawk, CA
  12. 2.6 3 km SE of Pleasant Hill, CA
  13. 1.9 2 km NW of Alamo, CA
  14. 1.8 2 km SE of Pacheco, CA
  15. 1.5 5 km E of Vallejo, 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 2.1 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.