QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8ml

40 km ENE of Condon, Montana

· 10 km deep · released about 480 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lake County 64 kmTeton County 73 kmMissoula County 88 kmLewis and Clark County 90 kmFlathead County 91 kmPowell County 96 kmPondera County 97 kmGlacier 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
Magnitude
M 2.8 (ml)
Depth
10 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
Lake County, 64 km W
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2799 days ago

A magnitude 2.8 earthquake was recorded 40 km ENE of Condon, Montana at 12:43 UTC on 2018-11-25. 1 person has reported feeling it to USGS. 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 480 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 32,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 22,000× the energy of this one
  3. Around the size people start to feel M 3.0 2× the energy of this one
  4. This earthquake M 2.8 about 480 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 47.6857, -113.2327. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lake County, MT 64 km (40 mi) W earthquakes near Lake County
Teton County, MT 73 km (45 mi) ENE earthquakes near Teton County
Missoula County, MT 88 km (55 mi) SW earthquakes near Missoula County
Lewis and Clark County, MT 90 km (56 mi) SE earthquakes near Lewis and Clark County
Flathead County, MT 91 km (57 mi) NW earthquakes near Flathead County
Powell County, MT 96 km (60 mi) SSE earthquakes near Powell County

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

Aftershocks so far

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

  1. 1.6 35 km NE of Seeley Lake, Montana
  2. 2.0 36 km NE of Seeley Lake, Montana
  3. 1.7 37 km NE of Seeley Lake, Montana
  4. 1.6 36 km NE of Seeley Lake, Montana
  5. 2.8 36 km NE of Seeley Lake, Montana
  6. 2.0 37 km NE of Seeley Lake, Montana
  7. 2.2 36 km NE of Seeley Lake, Montana
  8. 1.8 36 km NE of Seeley Lake, Montana
  9. 2.2 36 km NE of Seeley Lake, Montana
  10. 1.5 36 km NE of Seeley Lake, Montana
  11. 1.9 36 km NE of Seeley Lake, Montana
  12. 2.2 36 km NE of Seeley Lake, Montana
  13. 2.2 47 km WNW of Augusta, Montana
  14. 1.5 10 km ENE of Condon, Montana
  15. 2.3 25 km ENE 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.