26 km SE of Mammoth, Wyoming

2019-10-16 17:08 UTC · 8.3 km deep · released about 750 lb of TNT

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: 2019-10-16 17:08 UTC
Magnitude: M 2.9 (ml)
Depth: 8.3 km below the surface
Felt: no reports yet
Nearest: Park County, 74 km N
Status: Reviewed by a seismologist

USGS · last changed by USGS 2291 days ago · we first saw it 2291 days ago

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

How big was it?

This earthquake released about 750 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.

Mineral, Virginia 2011 M 5.8 20,000× the energy of this one
Magna, Utah 2020 M 5.7 14,000× the energy of this one
Around the size people start to feel M 3.0 1.3× the energy of this one
This earthquake M 2.9 about 750 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.

Where

Map loads when it scrolls into view

Epicentre 44.7938, -110.4902. Map © OpenStreetMap contributors.

Nearby places

Place	Distance	Direction
Park County, MT	74 km (46 mi)	S of here	earthquakes near Park County
Park County, WY	78 km (49 mi)	WNW of here	earthquakes near Park County
Teton County, WY	83 km (52 mi)	N of here	earthquakes near Teton County
Gallatin County, MT	96 km (60 mi)	SSE of here	earthquakes near Gallatin County
Fremont County, ID	102 km (63 mi)	NE of here	earthquakes near Fremont County
Sweet Grass County, MT	121 km (75 mi)	SSW of here	earthquakes near Sweet Grass County

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

Aftershocks so far

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

1.8 30 km E of West Yellowstone, Montana 17:20 UTC
1.6 15 km E of West Yellowstone, Montana 18:48 UTC
1.7 26 km ENE of West Yellowstone, Montana 04:44 UTC
1.8 26 km ENE of West Yellowstone, Montana 13:27 UTC
2.1 26 km ENE of West Yellowstone, Montana 12:14 UTC
1.6 26 km ENE of West Yellowstone, Montana 03:23 UTC
2.0 26 km ENE of West Yellowstone, Montana 02:24 UTC
1.6 32 km ESE of West Yellowstone, Montana 09:14 UTC
2.4 52 km SSE of Mammoth, Wyoming 13:14 UTC
1.9 52 km SSE of Mammoth, Wyoming 12:59 UTC
1.9 52 km SSE of Mammoth, Wyoming 12:57 UTC
1.7 40 km SSE of Mammoth, Wyoming 00:15 UTC
1.6 21 km S of Mammoth, Wyoming 10:44 UTC
1.7 22 km S of Mammoth, Wyoming 09:24 UTC
1.7 20 km S of Mammoth, Wyoming 09:18 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 12:35 UTC. QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

For this area

The largest earthquake within 50 km in our catalogue was M 4.4 on 2017-06-16 — it released about 140 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

The official USGS event page — the source of record for every value above
Did you feel it? Report it to USGS — reports go to USGS, not to us
ShakeMap for this event, when USGS has produced one

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.