QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

21 km SSW of Lima, Montana

Yes. A magnitude 1.5 earthquake was recorded 21 km SSW of Lima, Montana, at 5:04 pm MDT on 25 August 2022 (23:04 UTC), 10 km deep.

· 10 km deep · released about 5.4 lb of TNT

10 km30 km60 km120 km N Clark County 34 kmBeaverhead County 76 kmJefferson County 80 kmButte County 94 kmFremont County 101 kmLemhi County 107 kmMadison County 112 kmMadison County 115 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 1.5 (ml)
Depth
10 km below the surface
Felt
no reports yet
Nearest
Clark County, 34 km ESE
Nearest mapped fault
Red Rock fault, 19 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 1471 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 2 km (1 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 5.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,800,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 2,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 180× the energy of this one
  4. This earthquake M 1.5 about 5.4 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 4.6 on 2019-04-09 — about 45,000 times the energy of this one.

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

  1. 5.1 19 km NW of Lima, Montana · 35 km N of this epicentre
  2. 5.1 22 km NW of Lima, Montana · 37 km N 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 44.4586, -112.7105. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Clark County, ID 34 km (21 mi) ESE earthquakes near Clark County
Beaverhead County, MT 76 km (48 mi) N earthquakes near Beaverhead County
Jefferson County, ID 80 km (50 mi) SSE earthquakes near Jefferson County
Butte County, ID 94 km (58 mi) SSW earthquakes near Butte County
Fremont County, ID 101 km (63 mi) ESE earthquakes near Fremont County
Lemhi County, ID 107 km (66 mi) WNW earthquakes near Lemhi 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. 2.0 3 km SSE of Lima, Montana
  2. 2.0 3 km SSE of Lima, Montana
  3. 1.8 3 km SSE of Lima, Montana
  4. 1.5 3 km SE of Lima, Montana
  5. 2.5 28 km SSE of Leadore, Idaho
  6. 2.6 6 km E of Lima, Montana
  7. 2.4 Idaho-Montana border region
  8. 2.6 8 km ESE of Lima, Montana
  9. 2.0 35 km S of Lima, Montana
  10. 2.4 1 km WSW of Lima, Montana
  11. 2.2 8 km E of Lima, Montana
  12. 1.6 3 km SSE of Lima, Montana
  13. 1.7 3 km SSE of Lima, Montana
  14. 2.1 3 km SSE of Lima, Montana
  15. 2.3 3 km SSE of Lima, 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.