QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

6km S of Gilroy, CA

· 4.2 km deep · released about 43 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Santa Clara County 31 kmSanta Cruz County 39 kmSan Benito County 58 kmMerced County 80 kmAlameda County 82 kmMonterey County 83 kmStanislaus County 84 kmSan Mateo County 87 kmSan Joaquin County 112 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
4.2 km below the surface
Felt
no reports yet
Nearest
Santa Clara County, 31 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3161 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

How big was it?

This earthquake released about 43 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 5.8 350,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 250,000× the energy of this one
  3. Around the size people start to feel M 3.0 22× the energy of this one
  4. This earthquake M 2.1 about 43 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 36.9567, -121.5728. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Santa Clara County, CA 31 km (19 mi) SSE of here earthquakes near Santa Clara County
Santa Cruz County, CA 39 km (24 mi) E of here earthquakes near Santa Cruz County
San Benito County, CA 58 km (36 mi) NW of here earthquakes near San Benito County
Merced County, CA 80 km (50 mi) WSW of here earthquakes near Merced County
Alameda County, CA 82 km (51 mi) SSE of here earthquakes near Alameda County
Monterey County, CA 83 km (52 mi) NNW of here earthquakes near Monterey County

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

Aftershocks so far

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

  1. 3.4 11km NNW of Hollister, CA
  2. 1.8 24km WSW of Los Banos, CA
  3. 1.9 6km SW of Gilroy, CA
  4. 2.1 6km WSW of Gilroy, CA
  5. 2.3 12km SSE of Tres Pinos, CA
  6. 2.5 10km E of Gilroy, CA
  7. 1.9 10km E of Gilroy, CA
  8. 2.6 10km E of Gilroy, CA
  9. 3.3 10km E of Gilroy, CA
  10. 1.7 7km SSW of Ridgemark, CA
  11. 3.4 13km SSE of Tres Pinos, CA
  12. 2.1 16km SSE of Tres Pinos, CA
  13. 1.8 14km ESE of Alum Rock, CA
  14. 2.8 4km ESE of Aromas, CA
  15. 2.5 4km ESE of Aromas, 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 4.6 on 2017-11-13 — it released about 5,200 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.