QuakeIndex

Earthquake · reviewed by a seismologist

M 3.0ml

26 km WSW of Augusta, Montana

Yes. A magnitude 3.0 earthquake was recorded 26 km WSW of Augusta, Montana, at 4:18 am MST on 20 January 2025 (11:18 UTC), 30 km deep. 1 person has reported feeling it to USGS.

· 30 km deep · released about 950 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lewis and Clark County 43 kmTeton County 55 kmPowell County 67 kmPondera County 97 kmMissoula County 98 kmLake County 104 kmCascade County 105 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 3.0 (ml)
Depth
30 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
Lewis and Clark County, 43 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 592 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 21 km (13 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 950 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 350,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 16,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 11,000× the energy of this one
  4. This earthquake M 3.0 about 950 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 since 1900 lists no earthquake of M5 or more within 50 km.

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 47.4294, -112.7358. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lewis and Clark County, MT 43 km (27 mi) SE earthquakes near Lewis and Clark County
Teton County, MT 55 km (34 mi) NE earthquakes near Teton County
Powell County, MT 67 km (41 mi) SSW earthquakes near Powell County
Pondera County, MT 97 km (60 mi) NNE earthquakes near Pondera County
Missoula County, MT 98 km (61 mi) WSW earthquakes near Missoula County
Lake County, MT 104 km (65 mi) WNW earthquakes near Lake County

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

Aftershocks so far

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

  1. 1.0 22 km N of Ovando, Montana
  2. 2.3 22 km N of Ovando, Montana
  3. 1.6 28 km WSW of Augusta, Montana
  4. 1.9 24 km SSW of Augusta, Montana
  5. 1.1 27 km ENE of Seeley Lake, Montana
  6. 1.2 17 km WNW of Lincoln, Montana
  7. 1.4 38 km NNE of Ovando, Montana
  8. 1.3 41 km WSW of Augusta, Montana
  9. 1.6 23 km SSE of Augusta, Montana
  10. 2.4 32 km ENE of Seeley Lake, Montana
  11. 2.6 31 km ENE of Seeley Lake, Montana
  12. 2.1 25 km ENE of Seeley Lake, Montana
  13. 1.8 20 km N of Lincoln, Montana
  14. 3.1 27 km NE of Seeley Lake, Montana
  15. 1.5 40 km NE of Seeley Lake, 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.