QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5md

Earthquake near Mammoth Lakes, CA

No earthquake was likely felt in Mammoth Lakes in the 24 hours to 10:30 am PST (18:30 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 1.5 earthquake was recorded 41 km (25 mi) north-northeast of Mammoth Lakes, CA, at 2:51 pm PST on 28 February 2021 (22:51 UTC), less than 1 km deep.

USGS: 26km E of Lee Vining, CA

2:51 pm PST, Feb 28, 2021 · · 0.5 km deep · released about 5.7 lb of TNT

Every earthquake near Mammoth Lakes Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mono County 10 kmMineral County 68 kmTuolumne County 99 kmMariposa County 106 kmEsmeralda County 108 kmAlpine County 109 kmLyon County 118 kmMadera 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
2:51 pm PST on 28 February 2021 ()
Where
41 km (25 mi) north-northeast of Mammoth Lakes, CA · earthquakes near Mammoth Lakes
Magnitude
M 1.5 (md)
Depth
0.5 km below the surface
Felt
no reports yet
Nearest
Mono County, 10 km SSW
Nearest mapped fault
Huntoon Valley fault system, 11 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 2078 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 10 km (6 mi) from the epicentre. In Mammoth Lakes, 41 km away, the estimate is intensity I (not felt). 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 5.7 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,600,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,900,000× the energy of this one
  3. Around the size people start to feel M 3.0 170× the energy of this one
  4. This earthquake M 1.5 about 5.7 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 5.6 on 2016-12-28 — about 1,300,000 times the energy of this one.

Before 2016, the USGS record lists 28 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.1 11 km WNW of Aspen Springs, California · 45 km S of this epicentre
  2. 6.1 8 km W of Aspen Springs, California · 50 km S of this epicentre
  3. 6.0 Mammoth Lakes area, California · 49 km S of this epicentre
  4. 6.0 Mammoth Lakes area, California · 49 km S of this epicentre
  5. 6.0 7 km ENE of Mammoth Lakes, California · 36 km S 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 37.9988, -118.8332. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Mono County, CA 10 km (6 mi) SSW earthquakes near Mono County
Mineral County, NV 68 km (42 mi) NNE earthquakes near Mineral County
Tuolumne County, CA 99 km (62 mi) W earthquakes near Tuolumne County
Mariposa County, CA 106 km (66 mi) WSW earthquakes near Mariposa County
Esmeralda County, NV 108 km (67 mi) ESE earthquakes near Esmeralda County
Alpine County, CA 109 km (68 mi) NW earthquakes near Alpine County

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

Aftershocks so far

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

  1. 2.1 31km SE of Bodie, CA
  2. 1.5 34 km NW of Benton, California
  3. 1.5 33 km NW of Benton, California
  4. 1.5 20km NNW of Toms Place, CA
  5. 1.5 39km NNE of Toms Place, CA
  6. 2.8 13km W of Toms Place, CA
  7. 1.6 13km SE of Mammoth Lakes, CA
  8. 1.8 13km SE of Mammoth Lakes, CA
  9. 2.0 11km SE of Mammoth Lakes, CA
  10. 1.5 33 km ENE of Lee Vining, California
  11. 1.6 29km SE of Bodie, CA
  12. 1.6 38km NNE of Toms Place, CA
  13. 1.8 31km SSW of Qualeys Camp, NV
  14. 2.1 41km NNE of Toms Place, CA
  15. 1.6 7 km NE of Lee Vining, 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.

On USGS

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