QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

Earthquake near Deer Lodge, MT

USGS: 3 km WNW of Drummond, Montana

5:12 pm MST, Jan 21, 2020 · · 6.3 km deep · released about 14 lb of TNT

Every earthquake near Deer Lodge Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Powell County 26 kmGranite County 37 kmDeer Lodge County 66 kmMissoula County 66 kmLewis and Clark County 78 kmSilver Bow County 96 kmRavalli County 98 kmJefferson County 106 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
5:12 pm MST on 21 January 2020 ()
Where
47 km (29 mi) NW of Deer Lodge, MT · earthquakes near Deer Lodge
Magnitude
M 1.8 (ml)
Depth
6.3 km below the surface
Felt
no reports yet
Nearest
Powell County, 26 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2446 days ago

A magnitude 1.8 earthquake was recorded 47 km (29 mi) NW of Deer Lodge, MT, at 5:12 pm MST on 21 January 2020 (00:12 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

How big was it?

This earthquake released about 14 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 760,000× the energy of this one
  3. Around the size people start to feel M 3.0 68× the energy of this one
  4. This earthquake M 1.8 about 14 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 5.0 on 2017-07-06 — about 68,000 times the energy of this one.

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 46.6833, -113.1828. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Powell County, MT 26 km (16 mi) NE earthquakes near Powell County
Granite County, MT 37 km (23 mi) SSW earthquakes near Granite County
Deer Lodge County, MT 66 km (41 mi) S earthquakes near Deer Lodge County
Missoula County, MT 66 km (41 mi) NW earthquakes near Missoula County
Lewis and Clark County, MT 78 km (48 mi) NE earthquakes near Lewis and Clark County
Silver Bow County, MT 96 km (60 mi) SSE earthquakes near Silver Bow County

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

Aftershocks so far

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

  1. 2.2 7 km NW of Lincoln, Montana
  2. 2.9 Western Montana
  3. 1.7 9 km SW of Lincoln, Montana
  4. 1.8 11 km SW of Lincoln, Montana
  5. 1.7 16 km SSE of Lincoln, Montana
  6. 1.7 15 km WSW of Drummond, Montana
  7. 2.3 13 km ESE of Ovando, Montana
  8. 1.5 21 km NNW of Drummond, Montana
  9. 2.1 16 km ESE of Ovando, Montana
  10. 2.8 17 km ESE of Ovando, Montana
  11. 1.6 6 km NW of Drummond, Montana
  12. 1.6 10 km WNW of Avon, Montana
  13. 1.8 12 km SE of Seeley Lake, Montana
  14. 1.5 4 km S of Drummond, Montana
  15. 1.9 13 km WNW of Ovando, 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.