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 2:16 pm PST (22:16 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 37 km (23 mi) south-southwest of Mammoth Lakes, CA, at 11:06 pm PDT on 6 September 2020 (06:06 UTC), 2.1 km deep.

USGS: 33km NE of Shaver Lake, CA

88 km (54 mi) NE of Fresno, CA

11:06 pm PDT, Sep 6, 2020 · · 2.1 km deep · released about 5.9 lb of TNT

10 km30 km60 km120 km N Madera County 61 kmMono County 68 kmMariposa County 78 kmFresno County 81 kmTuolumne County 110 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
11:06 pm PDT on 6 September 2020 ()
Where
37 km (23 mi) south-southwest of Mammoth Lakes, CA · earthquakes near Mammoth Lakes
Magnitude
M 1.5 (md)
Depth
2.1 km below the surface
Felt
no reports yet
Nearest
Madera County, 61 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2249 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, 37 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 5.9 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 2,500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,800,000× the energy of this one
  3. Around the size people start to feel M 3.0 160× the energy of this one
  4. This earthquake M 1.5 about 5.9 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 21,000 times the energy of this one.

Before 2016, the USGS record lists 25 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.2 9 km SW of Aspen Springs, California · 31 km NE of this epicentre
  2. 6.1 11 km WNW of Aspen Springs, California · 37 km NE of this epicentre
  3. 6.1 8 km W of Aspen Springs, California · 35 km NE of this epicentre
  4. 6.1 4 km NNW of Round Valley, California · 44 km ENE of this epicentre
  5. 6.0 Mammoth Lakes area, California · 41 km NE 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 37.3275, -119.0818. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Madera County, CA 61 km (38 mi) WSW earthquakes near Madera County
Mono County, CA 68 km (42 mi) NNE earthquakes near Mono County
Mariposa County, CA 78 km (49 mi) WNW earthquakes near Mariposa County
Fresno County, CA 81 km (50 mi) SW earthquakes near Fresno County
Tuolumne County, CA 110 km (68 mi) NW earthquakes near Tuolumne County

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

Aftershocks so far

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

  1. 2.2 20km SE of Yosemite Valley, CA
  2. 1.6 22km ESE of Yosemite Valley, CA
  3. 1.6 21km SE of Yosemite Valley, CA
  4. 2.0 19km SE of Yosemite Valley, CA
  5. 1.7 20km SE of Yosemite Valley, CA
  6. 2.6 20km SE of Yosemite Valley, CA
  7. 3.1 20km SE of Yosemite Valley, CA
  8. 1.6 20km SE of Yosemite Valley, CA
  9. 2.4 20km ESE of Yosemite Valley, CA
  10. 2.3 18 km SE of Yosemite Valley, California
  11. 1.5 20km SE of Yosemite Valley, CA
  12. 2.2 19km SE of Yosemite Valley, CA
  13. 1.5 20km ESE of Yosemite Valley, CA
  14. 1.8 20km SE of Yosemite Valley, CA
  15. 1.5 22km ESE of Yosemite Valley, 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.