QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

4 km ENE of San Leandro, CA

· 8.6 km deep · released about 17 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Alameda County 21 kmContra Costa County 24 kmSan Mateo County 43 kmSolano County 60 kmMarin County 65 kmSanta Clara County 70 kmSan Joaquin County 77 kmSan Francisco County 80 kmSanta Cruz County 82 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 1.8 (md)
Depth
8.6 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
Alameda County, 21 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 831 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 1 person has reported feeling it to USGS.

How big was it?

This earthquake released about 17 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 900,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 640,000× the energy of this one
  3. Around the size people start to feel M 3.0 57× the energy of this one
  4. This earthquake M 1.8 about 17 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 37.7450, -122.1202. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Alameda County, CA 21 km (13 mi) WNW of here earthquakes near Alameda County
Contra Costa County, CA 24 km (15 mi) SW of here earthquakes near Contra Costa County
San Mateo County, CA 43 km (27 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 65 km (40 mi) ESE of here earthquakes near Marin County
Santa Clara County, CA 70 km (43 mi) NNW 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. 2.4 4 km ESE of El Sobrante, CA
  2. 1.6 4 km NNE of San Mateo, CA
  3. 1.7 2 km NNW of Diablo, CA
  4. 2.1 2 km SW of Alamo, CA
  5. 2.4 5 km NE of Castro Valley, CA
  6. 1.9 9 km E of Vallejo, CA
  7. 1.6 6 km NW of San Francisco Zoo, CA
  8. 1.6 5 km NE of Castro Valley, CA
  9. 2.0 11 km SSE of Suisun City, CA
  10. 1.9 4 km WNW of Los Altos Hills, CA
  11. 1.6 11 km SSE of Suisun City, CA
  12. 2.0 11 km SSE of Suisun City, CA
  13. 1.7 11 km SSE of Suisun City, CA
  14. 2.6 11 km SSE of Suisun City, CA
  15. 1.6 11 km SSE of Suisun City, 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 8,800 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.