QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

Earthquake near Yosemite Valley, CA

No earthquake was likely felt in Yosemite Valley in the 24 hours to 11:45 am PST (19:45 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 2.1 earthquake was recorded 21 km (13 mi) east-southeast of Yosemite Valley, CA, at 1:27 am PDT on 26 April 2021 (08:27 UTC), 17 km deep.

USGS: 21km ESE of Yosemite Valley, CA

1:27 am PDT, Apr 26, 2021 · · 17 km deep · released about 43 lb of TNT

10 km30 km60 km120 km N Mariposa County 49 kmMono County 52 kmMadera County 59 kmTuolumne County 67 kmFresno County 102 kmAlpine County 115 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
1:27 am PDT on 26 April 2021 ()
Where
21 km (13 mi) east-southeast of Yosemite Valley, CA · earthquakes near Yosemite Valley
Magnitude
M 2.1 (md)
Depth
17 km below the surface
Felt
no reports yet
Nearest
Mariposa County, 49 km W
Nearest mapped fault
Silver Lake fault, 25 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 2017 days ago

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

At this magnitude and depth, people at rest would likely notice it out to about 3 km (2 mi) from the epicentre. 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 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.

For this area

The largest earthquake within 50 km since 2016 was M 4.4 on 2020-02-01 — about 2,900 times the energy of this one.

Before 2016, the USGS record lists 12 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.1 11 km WNW of Aspen Springs, California · 48 km E of this epicentre
  2. 6.0 7 km ENE of Mammoth Lakes, California · 41 km E of this epicentre
  3. 5.9 8 km NNE of Mammoth Lakes, California · 40 km E of this epicentre
  4. 5.9 11 km SE of Mammoth Lakes, California · 45 km E of this epicentre
  5. 5.7 12 km ESE of Mammoth Lakes, California · 47 km E 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 37.6493, -119.3672. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Mariposa County, CA 49 km (30 mi) W earthquakes near Mariposa County
Mono County, CA 52 km (33 mi) NE earthquakes near Mono County
Madera County, CA 59 km (37 mi) SW earthquakes near Madera County
Tuolumne County, CA 67 km (42 mi) NW earthquakes near Tuolumne County
Fresno County, CA 102 km (63 mi) SSW earthquakes near Fresno County
Alpine County, CA 115 km (71 mi) NNW earthquakes near Alpine County

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

Aftershocks so far

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

  1. 1.6 12km SE of Mammoth Lakes, CA
  2. 1.8 22km SSE of Mammoth Lakes, CA
  3. 2.2 29km NE of Oakhurst, CA
  4. 1.7 20km SE of Yosemite Valley, CA
  5. 1.6 22km SW of Toms Place, CA
  6. 2.0 22km SW of Toms Place, CA
  7. 1.6 15km ESE of Yosemite Valley, CA
  8. 1.7 5km W of Mammoth Lakes, CA
  9. 1.9 18km WSW of Toms Place, CA
  10. 1.8 14km WSW of Toms Place, CA
  11. 1.5 14km SE of Mammoth Lakes, CA
  12. 1.9 14km SE of Mammoth Lakes, CA
  13. 1.9 19km SE of Yosemite Valley, CA
  14. 1.6 22km SW of Toms Place, CA
  15. 2.3 17km WSW of Toms Place, 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.