QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

15 km NE of Babb, Montana

Yes. A magnitude 1.8 earthquake was recorded 15 km NE of Babb, Montana, at 12:29 am MDT on 22 March 2020 (06:29 UTC), 20 km deep.

· 20 km deep · released about 17 lb of TNT

10 km30 km60 km120 km N Glacier County 38 kmFlathead County 93 kmPondera 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 1.8 (ml)
Depth
20 km below the surface
Felt
no reports yet
Nearest
Glacier County, 38 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2424 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. 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 17 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 5.8 870,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 620,000× the energy of this one
  3. Around the size people start to feel M 3.0 55× the energy of this one
  4. This earthquake M 1.8 about 17 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 48.9740, -113.3103. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Glacier County, MT 38 km (24 mi) SE earthquakes near Glacier County
Flathead County, MT 93 km (58 mi) SW earthquakes near Flathead County
Pondera County, MT 115 km (72 mi) SE earthquakes near Pondera County
Toole County, MT 121 km (75 mi) ESE earthquakes near Toole County

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

Aftershocks so far

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

  1. 2.3 6 km SSW of Cardston, Canada
  2. 1.7 21 km SSE of Cardston, Canada
  3. 2.8 8 km S of Cardston, Canada
  4. 1.7 14 km S of Cardston, Canada
  5. 2.0 Alberta, Canada
  6. 1.9 35 km SE of Cardston, Canada
  7. 1.9 10 km NNW of Babb, Montana
  8. 2.3 31 km S of Magrath, Canada
  9. 1.7 33 km SE of Cardston, Canada
  10. 2.3 31 km SE of Cardston, Canada
  11. 1.8 39 km ESE of Cardston, Canada
  12. 2.4 38 km ESE of Cardston, Canada
  13. 1.7 37 km ESE of Cardston, Canada
  14. 1.7 13 km S of Cardston, Canada

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.