QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

24km NE of Hetch Hetchy Reservoir, CA

· 9.5 km deep · released about 44 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Tuolumne County 33 kmAlpine County 60 kmMariposa County 65 kmMono County 67 kmCalaveras County 84 kmDouglas County 89 kmAmador County 100 kmMadera County 100 kmLyon County 108 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
9.5 km below the surface
Felt
no reports yet
Nearest
Tuolumne County, 33 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1600 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 44 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 5.8 340,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 240,000× 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 44 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 38.1032, -119.5970. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Tuolumne County, CA 33 km (21 mi) ENE of here earthquakes near Tuolumne County
Alpine County, CA 60 km (37 mi) SSE of here earthquakes near Alpine County
Mariposa County, CA 65 km (40 mi) NNE of here earthquakes near Mariposa County
Mono County, CA 67 km (41 mi) WNW of here earthquakes near Mono County
Calaveras County, CA 84 km (52 mi) E of here earthquakes near Calaveras County
Douglas County, NV 89 km (55 mi) S of here earthquakes near Douglas County

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

Aftershocks so far

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

  1. 1.6 4 km SSW of Coleville, California
  2. 1.6 4 km SSW of Coleville, California
  3. 2.2 6km WSW of Walker, CA
  4. 2.3 3km W of Walker, CA
  5. 3.1 3km W of Walker, CA
  6. 1.6 2 km NW of Walker, California
  7. 2.3 6km WSW of Walker, CA
  8. 3.2 4km W of Walker, CA
  9. 2.9 3km WNW of Walker, CA
  10. 2.2 3km W of Walker, CA
  11. 3.0 6km NW of Walker, CA
  12. 2.0 9km W of Bridgeport, CA
  13. 1.7 14km E of Yosemite Valley, CA
  14. 2.3 12km SW of Walker, CA
  15. 1.9 9 km WSW of Coleville, 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.

For this area

The largest earthquake within 50 km in our catalogue was M 6.0 on 2021-07-08 — it released about 680,000 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.