QuakeIndex

Earthquake · reviewed by a seismologist

M 1.2md

51 km NE of Alta, Wyoming

Yes. A magnitude 1.2 earthquake was recorded 51 km NE of Alta, Wyoming, at 10:05 pm MDT on 13 October 2026 (04:05 UTC), 9.0 km deep.

· 9.0 km deep · released about 1.7 lb of TNT

10 km30 km60 km120 km N Teton County 14 kmTeton County 62 kmFremont County 73 kmPark County 91 kmMadison County 92 kmBonneville County 113 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 1.2 (md)
Depth
9.0 km below the surface
Felt
no reports yet
Nearest
Teton County, 14 km ESE
Nearest mapped fault
East Mount Sheridan faults, 7 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 11 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. 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 1.7 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.2 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 8,800,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 6,200,000× the energy of this one
  3. Around the size people start to feel M 3.0 560× the energy of this one
  4. This earthquake M 1.2 about 1.7 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:

  1. 5.1 51 km ESE of West Yellowstone, Montana · 48 km N of this epicentre
  2. 5.0 62 km ESE of West Yellowstone, Montana · 41 km NNE 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 44.0908, -110.5890. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Teton County, WY 14 km (9 mi) ESE earthquakes near Teton County
Teton County, ID 62 km (38 mi) SW earthquakes near Teton County
Fremont County, ID 73 km (45 mi) WNW earthquakes near Fremont County
Park County, WY 91 km (57 mi) ENE earthquakes near Park County
Madison County, ID 92 km (57 mi) WSW earthquakes near Madison County
Bonneville County, ID 113 km (70 mi) SW earthquakes near Bonneville County

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

Aftershocks so far

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

  1. 1.4 68 km ESE of West Yellowstone, Montana
  2. 0.9 27 km SSE of West Yellowstone, Montana
  3. 1.5 53 km SE 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.