QuakeIndex

Earthquake · reviewed by a seismologist

M 3.3ml

40 km NE of Seeley Lake, Montana

· 23 km deep · released about 1.3 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lewis and Clark County 62 kmPowell County 65 kmTeton County 75 kmMissoula County 75 kmLake County 79 kmPondera County 111 kmGranite County 116 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 3.3 (ml)
Depth
23 km below the surface
Felt
5 reports · strongest reported intensity III
Nearest
Lewis and Clark County, 62 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2515 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 5 people have reported feeling it to USGS.

How big was it?

This earthquake released about 1.3 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.3 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 130,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 5,600× the energy of this one
  3. Magna, Utah 2020 M 5.7 4,000× the energy of this one
  4. This earthquake M 3.3 about 1.3 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 2.8× more

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

Epicentre 47.4166, -113.0815. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Lewis and Clark County, MT 62 km (39 mi) WNW of here earthquakes near Lewis and Clark County
Powell County, MT 65 km (40 mi) N of here earthquakes near Powell County
Teton County, MT 75 km (46 mi) SW of here earthquakes near Teton County
Missoula County, MT 75 km (47 mi) NE of here earthquakes near Missoula County
Lake County, MT 79 km (49 mi) ESE of here earthquakes near Lake County
Pondera County, MT 111 km (69 mi) SW of here earthquakes near Pondera County

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

Aftershocks so far

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

  1. 2.0 40 km WSW of Augusta, Montana
  2. 2.3 26 km ESE of Condon, Montana
  3. 2.1 14 km N of Seeley Lake, Montana
  4. 2.3 13 km ESE of Ovando, Montana
  5. 1.8 12 km SE of Seeley Lake, Montana
  6. 2.0 25 km NE of Ovando, Montana
  7. 1.9 13 km WNW of Ovando, Montana
  8. 2.7 26 km WSW of Augusta, Montana
  9. 1.8 16 km ESE of Ovando, Montana
  10. 1.7 16 km ESE of Ovando, Montana
  11. 1.8 25 km W of Augusta, Montana
  12. 1.6 36 km NE of Seeley Lake, Montana
  13. 2.4 37 km NE of Seeley Lake, Montana
  14. 2.0 27 km W of Augusta, Montana
  15. 1.5 37 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.