QuakeIndex

Earthquake · reviewed by a seismologist

M 3.8mw

3 km N of San Leandro, CA

· 5.5 km deep · released about 8.7 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Alameda County 24 kmContra Costa County 25 kmSan Mateo County 43 kmSolano County 60 kmMarin County 62 kmSanta Clara County 72 kmSan Francisco County 78 kmSan Joaquin County 80 kmSanta Cruz County 84 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 3.8 (mw)
Depth
5.5 km below the surface
Felt
7876 reports · strongest reported intensity IV
Measured shaking
intensity IV (ShakeMap)
USGS impact alert
green
Nearest
Alameda County, 24 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 9 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 7876 people have reported feeling it to USGS.

How big was it?

This earthquake released about 8.7 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.8 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 19,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 870× the energy of this one
  3. Magna, Utah 2020 M 5.7 620× the energy of this one
  4. This earthquake M 3.8 about 8.7 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 18× 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 37.7552, -122.1502. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Alameda County, CA 24 km (15 mi) WNW of here earthquakes near Alameda County
Contra Costa County, CA 25 km (16 mi) SW of here earthquakes near Contra Costa County
San Mateo County, CA 43 km (26 mi) NNE of here earthquakes near San Mateo County
Solano County, CA 60 km (37 mi) SSW of here earthquakes near Solano County
Marin County, CA 62 km (38 mi) ESE of here earthquakes near Marin County
Santa Clara County, CA 72 km (45 mi) NW of here earthquakes near Santa Clara County

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

Aftershocks so far

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

  1. 1.4 12 km SE of Livermore, CA
  2. 1.2 2 km E of Black Point-Green Point, CA
  3. 1.1 2 km NE of Danville, CA
  4. 1.4 12 km SE of Livermore, CA
  5. 1.1 13 km SE of Livermore, CA
  6. 0.9 20 km NE of Alum Rock, CA
  7. 1.4 4 km NNW of San Leandro, CA
  8. 2.3 2 km SE of Pacifica, CA
  9. 1.4 3 km SW of American Canyon, CA
  10. 1.7 3 km ENE of San Rafael, CA
  11. 2.0 9 km ESE of Livermore, CA
  12. 1.7 2 km NNE of Pleasant Hill, CA
  13. 1.2 2 km SE of Pacifica, CA
  14. 2.1 2 km NE of Pacifica, CA
  15. 2.5 10 km ENE of Milpitas, 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 8.5 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.