QuakeIndex

Earthquake · reviewed by a seismologist

M 3.6mw

9km ESE of Clayton, CA

· 16 km deep · released about 4.5 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Contra Costa County 10 kmAlameda County 31 kmSolano County 40 kmSan Joaquin County 50 kmSan Mateo County 73 kmSacramento County 73 kmNapa County 78 kmSanta Clara County 78 kmMarin County 81 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 3.6 (mw)
Depth
16 km below the surface
Felt
1692 reports · strongest reported intensity IV
Measured shaking
intensity IV (ShakeMap)
Nearest
Contra Costa County, 10 km W
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 201 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 1692 people have reported feeling it to USGS.

How big was it?

This earthquake released about 4.5 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.7 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 38,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 1,700× the energy of this one
  3. Magna, Utah 2020 M 5.7 1,200× the energy of this one
  4. This earthquake M 3.6 about 4.5 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 9.4× 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 37.9163, -121.8397. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Contra Costa County, CA 10 km (6 mi) E of here earthquakes near Contra Costa County
Alameda County, CA 31 km (19 mi) NNE of here earthquakes near Alameda County
Solano County, CA 40 km (25 mi) SSE of here earthquakes near Solano County
San Joaquin County, CA 50 km (31 mi) W of here earthquakes near San Joaquin County
San Mateo County, CA 73 km (45 mi) NE of here earthquakes near San Mateo County
Sacramento County, CA 73 km (46 mi) SW of here earthquakes near Sacramento County

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

Aftershocks so far

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

  1. 1.5 8 km SE of Sunol, CA
  2. 2.2 7 km SW of Brentwood, CA
  3. 2.6 8 km SW of Brentwood, CA
  4. 1.6 5 km E of Vallejo, CA
  5. 1.6 2 km NW of Pittsburg, CA
  6. 1.5 8 km NE of Milpitas, CA
  7. 2.3 9 km NE of Milpitas, CA
  8. 2.2 3 km N of Vallejo, CA
  9. 2.7 3 km N of Piedmont, CA
  10. 1.8 9 km E of Blackhawk, CA
  11. 1.6 6 km E of Vallejo, CA
  12. 1.9 12 km NE of Milpitas, CA
  13. 2.1 3 km NW of Castro Valley, CA
  14. 2.1 5 km ESE of Oakland, CA
  15. 1.6 4km E of Berkeley, 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 16 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.