QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near Yosemite Valley, CA

No earthquake was likely felt in Yosemite Valley in the 24 hours to 1:11 pm PST (21:11 UTC). The last one was M 2.5, 22 km (14 mi) SE, at 7:51 am PDT on 28 August 2026, estimated intensity II (weak) in town. Every earthquake near Yosemite Valley

This page: a magnitude 1.8 earthquake was recorded 21 km (13 mi) east-southeast of Yosemite Valley, CA, at 3:27 am PDT on 10 October 2021 (10:27 UTC), 16 km deep.

USGS: 20km ESE of Yosemite Valley, CA

3:27 am PDT, Oct 10, 2021 · · 16 km deep · released about 17 lb of TNT

10 km30 km60 km120 km N Mono County 49 kmMariposa County 51 kmMadera County 64 kmTuolumne County 65 kmFresno County 107 kmAlpine County 111 kmCalaveras County 119 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
3:27 am PDT on 10 October 2021 ()
Where
21 km (13 mi) east-southeast of Yosemite Valley, CA · earthquakes near Yosemite Valley
Magnitude
M 1.8 (md)
Depth
16 km below the surface
Felt
no reports yet
Nearest
Mono County, 49 km ENE
Nearest mapped fault
Silver Lake fault, 22 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1858 days ago

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

At this magnitude and depth it was probably too small to be felt, even directly above it. In Yosemite Valley, 21 km away, the estimate is intensity II (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

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.

For this area

The largest earthquake within 50 km since 2016 was M 4.4 on 2020-02-01 — about 7,400 times the energy of this one.

Before 2016, the USGS record lists 13 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.1 11 km WNW of Aspen Springs, California · 47 km ESE of this epicentre
  2. 6.0 7 km ENE of Mammoth Lakes, California · 40 km E of this epicentre
  3. 5.9 8 km NNE of Mammoth Lakes, California · 38 km E of this epicentre
  4. 5.9 11 km SE of Mammoth Lakes, California · 45 km ESE of this epicentre
  5. 5.8 3 km NE of Mono City, California · 46 km NNE of this epicentre

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 37.6902, -119.3537. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Mono County, CA 49 km (30 mi) ENE earthquakes near Mono County
Mariposa County, CA 51 km (32 mi) WSW earthquakes near Mariposa County
Madera County, CA 64 km (40 mi) SSW earthquakes near Madera County
Tuolumne County, CA 65 km (40 mi) NW earthquakes near Tuolumne County
Fresno County, CA 107 km (66 mi) SSW earthquakes near Fresno County
Alpine County, CA 111 km (69 mi) NNW earthquakes near Alpine 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. 1.6 17km WSW of Toms Place, CA
  2. 1.5 11km E of Mammoth Lakes, CA
  3. 1.8 29km NE of Oakhurst, CA
  4. 1.6 17km WSW of Mammoth Lakes, CA
  5. 1.9 30km NE of Oakhurst, CA
  6. 2.4 17km WSW of Mammoth Lakes, CA
  7. 1.6 7km ENE of Mammoth Lakes, CA
  8. 1.9 14km WNW of Toms Place, CA
  9. 2.0 14km WNW of Toms Place, CA
  10. 1.5 14km WNW of Toms Place, CA
  11. 1.7 14km WSW of Toms Place, CA
  12. 2.0 14km WNW of Toms Place, CA
  13. 1.8 20km SE of Yosemite Valley, CA
  14. 1.7 18km WSW of Toms Place, CA
  15. 1.6 7km N of Oakhurst, 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.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.