QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

Earthquake near Mammoth Lakes, CA

No earthquake was likely felt in Mammoth Lakes in the 24 hours to 12:57 pm PST (20:57 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 2.1 earthquake was recorded 34 km (21 mi) south of Mammoth Lakes, CA, at 3:56 pm PDT on 16 October 2023 (22:56 UTC), 14 km deep.

USGS: 31 km WSW of Round Valley, CA

99 km (61 mi) NE of Fresno, CA

3:56 pm PDT, Oct 16, 2023 · · 14 km deep · released about 40 lb of TNT

Every earthquake near Mammoth Lakes Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mono County 63 kmMadera County 74 kmMariposa County 90 kmFresno County 91 kmTuolumne County 117 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
3:56 pm PDT on 16 October 2023 ()
Where
34 km (21 mi) south of Mammoth Lakes, CA · earthquakes near Mammoth Lakes
Magnitude
M 2.1 (md)
Depth
14 km below the surface
Felt
no reports yet
Nearest
Mono County, 63 km N
Nearest mapped fault
Hilton Creek fault, 23 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 1122 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, 34 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 40 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 5.8 380,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 270,000× the energy of this one
  3. Around the size people start to feel M 3.0 24× the energy of this one
  4. This earthquake M 2.1 about 40 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 4.8 on 2016-02-16 — about 11,000 times the energy of this one.

Before 2016, the USGS record lists 33 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.4 The 1986 Chalfant Valley, California Earthquake · 48 km ENE of this epicentre
  2. 6.2 9 km SW of Aspen Springs, California · 21 km NE of this epicentre
  3. 6.1 11 km WNW of Aspen Springs, California · 28 km NNE of this epicentre
  4. 6.1 8 km W of Aspen Springs, California · 26 km NNE of this epicentre
  5. 6.1 4 km NNW of Round Valley, California · 32 km ENE 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 37.3487, -118.9358. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Mono County, CA 63 km (39 mi) N earthquakes near Mono County
Madera County, CA 74 km (46 mi) WSW earthquakes near Madera County
Mariposa County, CA 90 km (56 mi) WNW earthquakes near Mariposa County
Fresno County, CA 91 km (57 mi) SW earthquakes near Fresno County
Tuolumne County, CA 117 km (73 mi) NW earthquakes near Tuolumne County
Esmeralda County, NV 124 km (77 mi) ENE earthquakes near Esmeralda County

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

Aftershocks so far

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

  1. 1.6 17 km SE of Mammoth Lakes, CA
  2. 1.6 16 km WSW of Toms Place, CA
  3. 1.7 16 km WSW of Toms Place, CA
  4. 2.8 12 km ESE of Mammoth Lakes, CA
  5. 1.6 12 km W of Toms Place, CA
  6. 1.8 17 km WSW of Toms Place, CA
  7. 1.5 8 km ENE of Round Valley, CA
  8. 1.5 12 km ESE of Mammoth Lakes, CA
  9. 2.1 12 km ESE of Mammoth Lakes, CA
  10. 1.8 16 km SW of Toms Place, CA
  11. 1.9 12 km SE of Mammoth Lakes, CA
  12. 1.6 16 km WSW of Toms Place, CA
  13. 1.6 16 km SW of Toms Place, CA
  14. 1.7 17 km SW of Toms Place, CA
  15. 1.8 17 km 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.