QuakeIndex

Earthquake · reviewed by a seismologist

M 2.9md

Earthquake near Mammoth Lakes, CA

No earthquake was likely felt in Mammoth Lakes in the 24 hours to 5:40 am PST (13:40 UTC). The last one was M 2.9, 26 km (16 mi) SSE, at 3:54 am PDT on 24 October 2026, estimated intensity II (weak) in town. Every earthquake near Mammoth Lakes

This page: a magnitude 2.9 earthquake was recorded 15 km (9 mi) south of Mammoth Lakes, CA, at 12:19 pm PST on 25 February 2021 (20:19 UTC), 2.4 km deep.

USGS: 14km S of Mammoth Lakes, CA

12:19 pm PST, Feb 25, 2021 · · 2.4 km deep · released about 590 lb of TNT

10 km30 km60 km120 km N Mono County 46 kmMadera County 75 kmMariposa County 81 kmFresno County 102 kmTuolumne County 102 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
12:19 pm PST on 25 February 2021 ()
Where
15 km (9 mi) south of Mammoth Lakes, CA · earthquakes near Mammoth Lakes
Magnitude
M 2.9 (md)
Depth
2.4 km below the surface
Felt
no reports yet
Nearest
Mono County, 46 km NNE
Nearest mapped fault
Hilton Creek fault, 16 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 2018 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 30 km (19 mi) from the epicentre. In Mammoth Lakes, 15 km away, the estimate is intensity III (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.

Likely felt in: Mammoth Lakes 15 km, intensity III. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 590 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 26,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 18,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.6× the energy of this one
  4. This earthquake M 2.9 about 590 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 210 times the energy of this one.

Before 2016, the USGS record lists 31 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.4 The 1986 Chalfant Valley, California Earthquake · 49 km E of this epicentre
  2. 6.2 9 km SW of Aspen Springs, California · 17 km E of this epicentre
  3. 6.1 11 km WNW of Aspen Springs, California · 17 km ENE of this epicentre
  4. 6.1 8 km W of Aspen Springs, California · 17 km ENE of this epicentre
  5. 6.1 4 km NNW of Round Valley, California · 35 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 37.5132, -118.9942. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Mono County, CA 46 km (29 mi) NNE earthquakes near Mono County
Madera County, CA 75 km (46 mi) WSW earthquakes near Madera County
Mariposa County, CA 81 km (50 mi) W earthquakes near Mariposa County
Fresno County, CA 102 km (63 mi) SW earthquakes near Fresno County
Tuolumne County, CA 102 km (64 mi) NW earthquakes near Tuolumne County
Mineral County, NV 123 km (76 mi) NNE earthquakes near Mineral County

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

Aftershocks so far

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

  1. 2.0 11km SE of Mammoth Lakes, CA
  2. 1.8 14km ESE of Yosemite Valley, CA
  3. 1.9 18km SW of Toms Place, CA
  4. 1.6 21km SE of Yosemite Valley, CA
  5. 1.6 7km E of North Fork, CA
  6. 1.6 15km ESE of Yosemite Valley, CA
  7. 1.8 17km SSE of Mammoth Lakes, CA
  8. 1.6 14km ESE of Yosemite Valley, CA
  9. 1.8 9km W of Toms Place, CA
  10. 1.8 9km WSW of Toms Place, CA
  11. 2.8 19km SW of Toms Place, CA
  12. 2.2 19km SW of Toms Place, CA
  13. 2.1 13km W of Toms Place, CA
  14. 1.6 12km NNE of Round Valley, CA
  15. 1.5 17km SW 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.