QuakeIndex

Earthquake · reviewed by a seismologist

M 2.4md

6km SSE of Bridgeport, CA

Yes. A magnitude 2.4 earthquake was recorded 6km SSE of Bridgeport, CA, at 8:54 pm PDT on 12 July 2021 (03:54 UTC), 6.1 km deep. 2 people have reported feeling it to USGS.

· 6.1 km deep · released about 110 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mono County 43 kmAlpine County 69 kmTuolumne County 70 kmMineral County 77 kmDouglas County 85 kmLyon County 91 kmMariposa County 94 kmCarson City 115 kmCalaveras County 118 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 2.4 (md)
Depth
6.1 km below the surface
Felt
2 reports · strongest reported intensity II
Nearest
Mono County, 43 km SE
Nearest mapped fault
Robinson Creek fault, 9 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 1947 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 20 km (12 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 110 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.4 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 130,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 95,000× the energy of this one
  3. Around the size people start to feel M 3.0 8.5× the energy of this one
  4. This earthquake M 2.4 about 110 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 6.0 on 2021-07-08 — about 270,000 times the energy of this one.

Before 2016, the USGS record lists 9 earthquakes of M5 or more within 50 km; the five largest:

  1. 5.8 3 km NE of Mono City, California · 18 km SSE of this epicentre
  2. 5.2 23 km S of Walker, California · 28 km WNW of this epicentre
  3. 5.2 21 km S of Hawthorne, Nevada · 49 km ENE of this epicentre
  4. 5.2 31 km ENE of Mono City, California · 34 km E of this epicentre
  5. 5.1 23 km E of Bridgeport, California · 22 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 38.2057, -119.2035. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Mono County, CA 43 km (27 mi) SE earthquakes near Mono County
Alpine County, CA 69 km (43 mi) NW earthquakes near Alpine County
Tuolumne County, CA 70 km (43 mi) WSW earthquakes near Tuolumne County
Mineral County, NV 77 km (48 mi) ENE earthquakes near Mineral County
Douglas County, NV 85 km (53 mi) NNW earthquakes near Douglas County
Lyon County, NV 91 km (56 mi) N earthquakes near Lyon County

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

Aftershocks so far

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

  1. 1.7 29km SSW of Smith Valley, NV
  2. 2.1 29km SSW of Smith Valley, NV
  3. 2.4 28km SSW of Smith Valley, NV
  4. 2.4 28km SSW of Smith Valley, NV
  5. 2.1 29km SSW of Smith Valley, NV
  6. 3.9 28km SSW of Smith Valley, NV
  7. 2.2 26km SSW of Smith Valley, NV
  8. 1.6 32km NW of Bridgeport, CA
  9. 1.5 32km ENE of Dardanelle, CA
  10. 1.5 29km SE of Markleeville, CA
  11. 1.8 30km ENE of Dardanelle, CA
  12. 1.6 26km SSW of Smith Valley, NV
  13. 1.5 29km SSW of Smith Valley, NV
  14. 1.5 28km ESE of Markleeville, CA
  15. 1.5 32km ENE of Dardanelle, 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.