QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3ml

11 km ESE of Jardine, Montana

Yes. A magnitude 2.3 earthquake was recorded 11 km ESE of Jardine, Montana, at 9:49 pm MDT on 23 July 2021 (03:49 UTC), 13 km deep.

· 13 km deep · released about 79 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Park County 49 kmGallatin County 75 kmPark County 93 kmSweet Grass County 98 kmTeton County 109 kmStillwater County 113 kmMadison County 115 kmCarbon County 118 kmFremont 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
Montana today
every earthquake in Montana in the last 24 hours
Magnitude
M 2.3 (ml)
Depth
13 km below the surface
Felt
no reports yet
Nearest
Park County, 49 km N
Nearest mapped fault
Mirror Plateau faults, 23 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 1934 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 14 km (9 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 79 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 190,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 130,000× the energy of this one
  3. Around the size people start to feel M 3.0 12× the energy of this one
  4. This earthquake M 2.3 about 79 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 2017-06-16 — about 1,300 times the energy of this one.

Before 2016, the USGS record lists 10 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.5 14 km N of Madison Junction, Wyoming · 42 km SW of this epicentre
  2. 6.3 22 km SW of Mammoth, Wyoming · 37 km SW of this epicentre
  3. 6.0 21 km E of West Yellowstone, Montana · 49 km SSW of this epicentre
  4. 5.9 26 km SSE of Mammoth, Wyoming · 32 km SSW of this epicentre
  5. 5.7 13 km SSW of Mammoth, Wyoming · 26 km SW 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 45.0237, -110.5058. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Park County, MT 49 km (30 mi) N earthquakes near Park County
Gallatin County, MT 75 km (47 mi) NW earthquakes near Gallatin County
Park County, WY 93 km (58 mi) SE earthquakes near Park County
Sweet Grass County, MT 98 km (61 mi) NNE earthquakes near Sweet Grass County
Teton County, WY 109 km (67 mi) S earthquakes near Teton County
Stillwater County, MT 113 km (70 mi) NE earthquakes near Stillwater County

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

Aftershocks so far

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

  1. 2.1 28 km S of Mammoth, Wyoming
  2. 1.7 Wyoming
  3. 1.8 29 km S of Mammoth, Wyoming
  4. 1.6 29 km S of Mammoth, Wyoming
  5. 1.9 22 km S of Mammoth, Wyoming
  6. 1.5 28 km E of West Yellowstone, Montana
  7. 1.5 28 km E of West Yellowstone, Montana
  8. 1.5 23 km SSE of Mammoth, Wyoming
  9. 1.6 25 km SSE of Mammoth, Wyoming
  10. 1.5 24 km SSE of Mammoth, Wyoming
  11. 1.5 24 km SSE of Mammoth, Wyoming
  12. 2.6 25 km SSE of Mammoth, Wyoming
  13. 1.6 23 km SSE of Mammoth, Wyoming
  14. 1.6 25 km SSE of Mammoth, Wyoming
  15. 1.6 25 km SSE of Mammoth, Wyoming

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.