QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8md

12 km ESE of East Foothills, California

· 10 km deep · released about 530 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Santa Clara County 13 kmAlameda County 39 kmSanta Cruz County 46 kmSan Mateo County 61 kmStanislaus County 66 kmContra Costa County 68 kmSan Joaquin County 76 kmMerced County 87 kmSan Benito County 97 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 2.8 (md)
Depth
10 km below the surface
Felt
11 reports · strongest reported intensity III
Nearest
Santa Clara County, 13 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3503 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 11 people have reported feeling it to USGS.

How big was it?

This earthquake released about 530 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 29,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 20,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.8× the energy of this one
  4. This earthquake M 2.8 about 530 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 37.3395, -121.6912. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Santa Clara County, CA 13 km (8 mi) N of here earthquakes near Santa Clara County
Alameda County, CA 39 km (24 mi) SSE of here earthquakes near Alameda County
Santa Cruz County, CA 46 km (29 mi) NE of here earthquakes near Santa Cruz County
San Mateo County, CA 61 km (38 mi) E of here earthquakes near San Mateo County
Stanislaus County, CA 66 km (41 mi) WSW of here earthquakes near Stanislaus County
Contra Costa County, CA 68 km (43 mi) SSE of here earthquakes near Contra Costa County

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

Aftershocks so far

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

  1. 2.5 6 km NNE of East Foothills, California
  2. 1.8 8 km SE of Livermore, California
  3. 2.1 1 km SSE of Livermore, California
  4. 2.6 2 km SSE of Livermore, California
  5. 1.9 1 km SSE of Livermore, California
  6. 1.6 Northern California
  7. 1.8 2 km SSE of Livermore, California
  8. 1.6 1 km SSE of Livermore, California
  9. 1.6 1 km SSE of Livermore, California
  10. 1.6 1 km SSW of Livermore, California
  11. 2.7 2 km SSE of Livermore, California
  12. 2.1 2 km SSE of Livermore, California
  13. 1.5 12km SSE of Livermore, CA
  14. 2.5 13 km N of Morgan Hill, California
  15. 1.5 11 km SSE of Livermore, California

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.