QuakeIndex

Earthquake · reviewed by a seismologist

M 3.7ml

56 km SSE of Mammoth, Wyoming

Yes. A magnitude 3.7 earthquake was recorded 56 km SSE of Mammoth, Wyoming, at 8:24 am MDT on 29 March 2023 (14:24 UTC), 3.7 km deep. 3 people have reported feeling it to USGS.

· 3.7 km deep · released about 5.7 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Teton County 53 kmPark County 61 kmFremont County 96 kmPark County 105 kmTeton County 109 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 3.7 (ml)
Depth
3.7 km below the surface
Felt
3 reports · strongest reported intensity III
Nearest
Teton County, 53 km S
Nearest mapped fault
Eagle Bay fault, 3 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 1257 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 77 km (48 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 5.7 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.7 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 30,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 1,300× the energy of this one
  3. Magna, Utah 2020 M 5.7 930× the energy of this one
  4. This earthquake M 3.7 about 5.7 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 12× more

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 4.2 on 2022-05-11 — about 5.6 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 · 50 km WNW of this epicentre
  2. 6.0 21 km E of West Yellowstone, Montana · 40 km WNW of this epicentre
  3. 5.9 26 km SSE of Mammoth, Wyoming · 31 km NW of this epicentre
  4. 5.7 13 km SSW of Mammoth, Wyoming · 49 km NW of this epicentre
  5. 5.5 25 km SSW of Mammoth, Wyoming · 43 km NW 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 44.5253, -110.3612. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Teton County, WY 53 km (33 mi) S earthquakes near Teton County
Park County, WY 61 km (38 mi) E earthquakes near Park County
Fremont County, ID 96 km (59 mi) WSW earthquakes near Fremont County
Park County, MT 105 km (65 mi) N earthquakes near Park County
Teton County, ID 109 km (68 mi) SW earthquakes near Teton County
Gallatin County, MT 127 km (79 mi) NNW earthquakes near Gallatin 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. 1.8 45 km ESE of West Yellowstone, Montana
  2. 1.8 46 km ESE of West Yellowstone, Montana
  3. 2.3 45 km ESE of West Yellowstone, Montana
  4. 1.8 45 km ESE of West Yellowstone, Montana
  5. 2.1 45 km ESE of West Yellowstone, Montana
  6. 1.9 44 km ESE of West Yellowstone, Montana
  7. 1.6 45 km ESE of West Yellowstone, Montana
  8. 1.7 23 km SSW of Mammoth, Wyoming
  9. 1.6 64 km SSW of Silver Gate, Montana
  10. 1.9 64 km SSW of Silver Gate, Montana
  11. 1.6 21 km SSW of Mammoth, Wyoming
  12. 1.7 45 km ESE of West Yellowstone, Montana
  13. 1.5 49 km ESE of West Yellowstone, Montana
  14. 2.0 45 km ESE of West Yellowstone, Montana
  15. 1.6 49 km ESE of West Yellowstone, Montana

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.