QuakeIndex

Earthquake · reviewed by a seismologist

M 2.2md

Earthquake near Mammoth Lakes, CA

No earthquake was likely felt in Mammoth Lakes in the 24 hours to 1:47 pm PST (21:47 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 2.2 earthquake was recorded 33 km (21 mi) east-southeast of Mammoth Lakes, CA, at 9:28 am PDT on 4 October 2020 (16:28 UTC), 9.2 km deep.

USGS: 6km E of Toms Place, CA

9:28 am PDT, Oct 4, 2020 · · 9.2 km deep · released about 69 lb of TNT

10 km30 km60 km120 km N Mono County 46 kmEsmeralda County 89 kmMineral County 108 kmMadera County 108 kmMariposa 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
9:28 am PDT on 4 October 2020 ()
Where
33 km (21 mi) east-southeast of Mammoth Lakes, CA · earthquakes near Mammoth Lakes
Magnitude
M 2.2 (md)
Depth
9.2 km below the surface
Felt
no reports yet
Nearest
Mono County, 46 km NNW
Nearest mapped fault
Long Valley fault, 2 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 1648 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 17 km (11 mi) from the epicentre. In Mammoth Lakes, 33 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.

Earthquakes near other towns within 30 km: Dixon Lane-Meadow Creek, West Bishop, Bishop.

How big was it?

This earthquake released about 69 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.2 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 220,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 150,000× the energy of this one
  3. Around the size people start to feel M 3.0 14× the energy of this one
  4. This earthquake M 2.2 about 69 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 6,200 times the energy of this one.

Before 2016, the USGS record lists 41 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.4 The 1986 Chalfant Valley, California Earthquake · 15 km E of this epicentre
  2. 6.2 9 km SW of Aspen Springs, California · 18 km WSW of this epicentre
  3. 6.1 11 km WNW of Aspen Springs, California · 20 km W of this epicentre
  4. 6.1 8 km W of Aspen Springs, California · 17 km W of this epicentre
  5. 6.1 4 km NNW of Round Valley, California · 11 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 37.5600, -118.6103. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Mono County, CA 46 km (29 mi) NNW earthquakes near Mono County
Esmeralda County, NV 89 km (56 mi) ENE earthquakes near Esmeralda County
Mineral County, NV 108 km (67 mi) N earthquakes near Mineral County
Madera County, CA 108 km (67 mi) WSW earthquakes near Madera County
Mariposa County, CA 115 km (71 mi) W earthquakes near Mariposa County
Fresno County, CA 128 km (80 mi) SW earthquakes near Fresno 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. 1.9 38km SSW of Qualeys Camp, NV
  2. 1.7 15km WSW of Toms Place, CA
  3. 2.0 10km SSW of Toms Place, CA
  4. 2.1 43km NNE of Toms Place, CA
  5. 1.9 16 km NW of Dyer, Nevada
  6. 2.7 11km SW of Toms Place, CA
  7. 1.8 9km ESE of Mammoth Lakes, CA
  8. 1.7 9km E of Mammoth Lakes, CA
  9. 2.3 6km ESE of Round Valley, CA
  10. 1.5 26 km NW of Benton, California
  11. 2.9 19km NNW of Toms Place, CA
  12. 1.7 12km E of Mammoth Lakes, CA
  13. 1.9 11km E of Mammoth Lakes, CA
  14. 2.0 15km SW of Toms Place, CA
  15. 2.0 8km NE of Big Pine, 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.