QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9md

Earthquake near Mammoth Lakes, CA

No earthquake was likely felt in Mammoth Lakes in the 24 hours to 12:28 pm PST (20:28 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 1.9 earthquake was recorded 48 km (30 mi) north-northeast of Mammoth Lakes, CA, at 10:14 am PDT on 27 August 2020 (17:14 UTC), less than 1 km deep.

USGS: 31km SE of Bodie, CA

10:14 am PDT, Aug 27, 2020 · · 0.2 km deep · released about 25 lb of TNT

Every earthquake near Mammoth Lakes Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mono County 19 kmMineral County 60 kmEsmeralda County 101 kmTuolumne County 108 kmAlpine County 113 kmMariposa County 116 kmLyon County 116 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
10:14 am PDT on 27 August 2020 ()
Where
48 km (30 mi) north-northeast of Mammoth Lakes, CA · earthquakes near Mammoth Lakes
Magnitude
M 1.9 (md)
Depth
0.2 km below the surface
Felt
no reports yet
Nearest
Mono County, 19 km SW
Nearest mapped fault
Huntoon Valley fault system, 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 2268 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 15 km (9 mi) from the epicentre. In Mammoth Lakes, 48 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 25 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.0 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 600,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 420,000× the energy of this one
  3. Around the size people start to feel M 3.0 38× the energy of this one
  4. This earthquake M 1.9 about 25 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 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. 6.3 The 1934 Excelsior Mountains, Nevada Earthquake · 42 km NE of this epicentre
  2. 6.0 7 km ENE of Mammoth Lakes, California · 43 km SSW of this epicentre
  3. 5.9 8 km NNE of Mammoth Lakes, California · 40 km SSW of this epicentre
  4. 5.8 3 km NE of Mono City, California · 34 km W of this epicentre
  5. 5.7 12 km ESE of Mammoth Lakes, California · 48 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 38.0420, -118.7338. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Mono County, CA 19 km (12 mi) SW earthquakes near Mono County
Mineral County, NV 60 km (37 mi) NNE earthquakes near Mineral County
Esmeralda County, NV 101 km (63 mi) ESE earthquakes near Esmeralda County
Tuolumne County, CA 108 km (67 mi) W earthquakes near Tuolumne County
Alpine County, CA 113 km (70 mi) NW earthquakes near Alpine County
Mariposa County, CA 116 km (72 mi) WSW earthquakes near Mariposa County

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

Aftershocks so far

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

  1. 1.6 30km SE of Bodie, CA
  2. 1.6 30km ESE of Bodie, CA
  3. 1.6 30km SE of Bodie, CA
  4. 1.6 5km E of Mammoth Lakes, CA
  5. 1.5 19 km SSE of Hawthorne, Nevada
  6. 2.1 5km E of Mammoth Lakes, CA
  7. 1.6 30km SE of Bodie, CA
  8. 3.0 5km E of Mammoth Lakes, CA
  9. 2.6 5km E of Mammoth Lakes, CA
  10. 1.7 5km E of Mammoth Lakes, CA
  11. 1.6 27 km NE of Benton, California
  12. 2.1 29km SE of Bodie, CA
  13. 1.6 5km E of Mammoth Lakes, CA
  14. 1.7 5km E of Mammoth Lakes, CA
  15. 1.7 40km E of Lee Vining, 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.