48 km NE of Spencer, Idaho

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 23 km (14 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 340 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 45,000× the energy of this one
2. Magna, Utah 2020 M 5.7 32,000× the energy of this one
3. Around the size people start to feel M 3.0 2.8× the energy of this one
4. This earthquake M 2.7 about 340 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 4.3 on 2016-06-13 — about 290 times the energy of this one.

Before 2016, the USGS record lists 5 earthquakes of M5 or more within 50 km:

1. 6.1 30 km SSW of Big Sky, Montana · 43 km NNE of this epicentre Nov 23, 1947
2. 5.2 32 km WNW of Hebgen Lake Estates, Montana · 28 km NE of this epicentre Oct 21, 1964
3. 5.2 26 km WNW of Hebgen Lake Estates, Montana · 30 km ENE of this epicentre Mar 11, 1977
4. 5.0 31 km W of Hebgen Lake Estates, Montana · 23 km ENE of this epicentre Aug 19, 1959
5. 5.0 39 km W of Hebgen Lake Estates, Montana · 12 km E of this epicentre Aug 20, 1959

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 44.7120, -111.8333. Map © OpenStreetMap contributors.

Nearby places

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. 1.0 29 km WNW of Hebgen Lake Estates, Montana 01:59 UTC
2. 1.3 28 km S of Ennis, Montana 22:36 UTC
3. 0.2 11 km WSW of Hebgen Lake Estates, Montana 14:11 UTC
4. 0.8 26 km W of Hebgen Lake Estates, Montana 19:33 UTC
5. 0.4 53 km NNE of Spencer, Idaho 19:31 UTC
6. -0.0 25 km WNW of Hebgen Lake Estates, Montana 00:51 UTC
7. 1.4 50 km S of Virginia City, Montana 23:19 UTC
8. 0.1 10 km WNW of Hebgen Lake Estates, Montana 12:28 UTC
9. -0.1 27 km W of Hebgen Lake Estates, Montana 01:12 UTC
10. 0.4 50 km NNE of Spencer, Idaho 18:34 UTC
11. 1.7 10 km WSW of Hebgen Lake Estates, Montana 17:17 UTC
12. 0.1 25 km WNW of Hebgen Lake Estates, Montana 13:09 UTC
13. -0.0 17 km W of Hebgen Lake Estates, Montana 06:14 UTC
14. 0.1 27 km WNW of Hebgen Lake Estates, Montana 14:53 UTC
15. 0.0 30 km WNW of Hebgen Lake Estates, Montana 01:45 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 23:10 UTC. QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

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.