QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

4 km SW of Saratoga, California

· 7.7 km deep · released about 38 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Santa Cruz County 25 kmSanta Clara County 32 kmSan Mateo County 34 kmAlameda County 47 kmContra Costa County 76 kmStanislaus County 100 kmSan Francisco County 102 kmSan Joaquin County 104 kmMarin County 109 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 2.1 (md)
Depth
7.7 km below the surface
Felt
5 reports · strongest reported intensity II
Nearest
Santa Cruz County, 25 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1512 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 5 people have reported feeling it to USGS.

How big was it?

This earthquake released about 38 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 390,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 280,000× the energy of this one
  3. Around the size people start to feel M 3.0 25× the energy of this one
  4. This earthquake M 2.1 about 38 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 37.2367, -122.0555. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Santa Cruz County, CA 25 km (16 mi) N of here earthquakes near Santa Cruz County
Santa Clara County, CA 32 km (20 mi) W of here earthquakes near Santa Clara County
San Mateo County, CA 34 km (21 mi) SE of here earthquakes near San Mateo County
Alameda County, CA 47 km (29 mi) SSW of here earthquakes near Alameda County
Contra Costa County, CA 76 km (48 mi) S of here earthquakes near Contra Costa County
Stanislaus County, CA 100 km (62 mi) WSW of here earthquakes near Stanislaus County

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

Aftershocks so far

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

  1. 1.7 7km E of Alum Rock, CA
  2. 1.9 4km NE of Portola Valley, CA
  3. 1.6 3 km W of Portola Valley, California
  4. 1.8 4 km WNW of La Honda, California
  5. 1.5 11 km ESE of East Foothills, California
  6. 1.7 1 km N of North Fair Oaks, California
  7. 1.6 7 km WSW of Gilroy, California
  8. 1.9 14 km E of Seven Trees, California
  9. 1.7 5 km SW of Gilroy, California
  10. 2.0 10 km ENE of Milpitas, California
  11. 2.4 7 km WSW of Gilroy, California
  12. 2.2 8 km ENE of San Martin, California
  13. 1.6 12 km ESE of East Foothills, California
  14. 2.7 8 km ENE of San Martin, California
  15. 2.3 5 km SW of Gilroy, 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.