QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

28 km E of Mono City, California

Yes. A magnitude 2.1 earthquake was recorded 28 km E of Mono City, California, at 9:03 pm PST on 23 February 2017 (05:03 UTC), 2.0 km deep. 1 person has reported feeling it to USGS.

· 2.0 km deep · released about 41 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mono County 19 kmMineral County 60 kmTuolumne County 100 kmAlpine County 104 kmLyon County 109 kmEsmeralda County 110 kmMariposa County 111 kmDouglas County 114 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
Magnitude
M 2.1 (md)
Depth
2.0 km below the surface
Felt
1 report · strongest reported intensity III
Nearest
Mono County, 19 km SSW
Nearest mapped fault
Huntoon Valley fault system, 12 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 3056 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. 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 41 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 5.8 370,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 260,000× the energy of this one
  3. Around the size people start to feel M 3.0 23× the energy of this one
  4. This earthquake M 2.1 about 41 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 180,000 times the energy of this one.

Before 2016, the USGS record lists 21 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.3 The 1934 Excelsior Mountains, Nevada Earthquake · 46 km ENE of this epicentre
  2. 6.0 7 km ENE of Mammoth Lakes, California · 46 km S of this epicentre
  3. 5.9 8 km NNE of Mammoth Lakes, California · 42 km SSW of this epicentre
  4. 5.8 3 km NE of Mono City, California · 26 km W of this epicentre
  5. 5.6 Excelsior Mountains, Nevada (Foreshock) · 44 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 38.0843, -118.8277. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Mono County, CA 19 km (12 mi) SSW earthquakes near Mono County
Mineral County, NV 60 km (37 mi) NE earthquakes near Mineral County
Tuolumne County, CA 100 km (62 mi) W earthquakes near Tuolumne County
Alpine County, CA 104 km (64 mi) NW earthquakes near Alpine County
Lyon County, NV 109 km (68 mi) NNW earthquakes near Lyon County
Esmeralda County, NV 110 km (68 mi) ESE earthquakes near Esmeralda 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. 2.3 29 km SSW of Hawthorne, Nevada
  2. 2.0 29 km SSW of Hawthorne, Nevada
  3. 1.9 29 km SSW of Hawthorne, Nevada
  4. 1.8 30 km SSW of Hawthorne, Nevada
  5. 1.8 30 km SSW of Hawthorne, Nevada
  6. 1.9 29 km SSW of Hawthorne, Nevada
  7. 1.5 29 km SSW of Hawthorne, Nevada
  8. 2.5 28 km SSW of Hawthorne, Nevada
  9. 2.2 29 km SSW of Hawthorne, Nevada
  10. 1.6 29 km SSW of Hawthorne, Nevada
  11. 1.6 30 km SSW of Hawthorne, Nevada
  12. 2.3 29 km SSW of Hawthorne, Nevada
  13. 2.0 California-Nevada border region
  14. 1.6 California-Nevada border region
  15. 1.8 29 km SSW of Hawthorne, Nevada

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.