QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

Earthquake near Townsend, MT

No earthquake was likely felt in Townsend in the 24 hours to 7:46 am MST (14:46 UTC). The last one was M 1.7, 9 km (5 mi) W, at 2:32 pm MDT on 15 October 2026, estimated intensity II (weak) in town. Every earthquake near Townsend

This page: a magnitude 1.5 earthquake was recorded 18 km (11 mi) southeast of Townsend, MT, at 1:18 pm MDT on 5 June 2021 (19:18 UTC), less than 1 km deep.

USGS: 8 km ENE of Toston, Montana

1:18 pm MDT, Jun 5, 2021 · · -2.6 km deep · released about 5.6 lb of TNT

Every earthquake near Townsend Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Broadwater County 17 kmMeagher County 52 kmJefferson County 56 kmGallatin County 79 kmPark County 105 kmSilver Bow County 108 kmMadison County 108 kmSweet Grass County 117 kmWheatland County 118 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
1:18 pm MDT on 5 June 2021 ()
Where
18 km (11 mi) southeast of Townsend, MT · earthquakes near Townsend
Montana today
every earthquake in Montana in the last 24 hours
Magnitude
M 1.5 (ml)
Depth
-2.6 km below the surface
Felt
no reports yet
Nearest
Broadwater County, 17 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1983 days ago

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

At this magnitude and depth, people at rest would likely notice it out to about 10 km (6 mi) from the epicentre. In Townsend, 18 km away, the estimate is intensity II (weak). 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 5.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,700,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,900,000× the energy of this one
  3. Around the size people start to feel M 3.0 170× the energy of this one
  4. This earthquake M 1.5 about 5.6 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 4.2 on 2019-08-16 — about 11,000 times the energy of this one.

Before 2016, the USGS record lists 7 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.6 The 1925 Clarkston Valley, Montana Earthquake · 20 km SW of this epicentre
  2. 6.4 Clarkston Valley, Montana (Aftershock) · 20 km SW of this epicentre
  3. 6.1 The 1935 Helena, Montana Earthquakes (Mainshock) · 48 km NNW of this epicentre
  4. 5.5 Clarkston Valley, Montana (Aftershock) · 20 km SW of this epicentre
  5. 5.5 Clarkston Valley, Montana (Aftershock) · 20 km SW of this epicentre

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 46.2160, -111.3448. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Broadwater County, MT 17 km (11 mi) NW earthquakes near Broadwater County
Meagher County, MT 52 km (33 mi) NE earthquakes near Meagher County
Jefferson County, MT 56 km (35 mi) W earthquakes near Jefferson County
Gallatin County, MT 79 km (49 mi) S earthquakes near Gallatin County
Park County, MT 105 km (65 mi) SE earthquakes near Park County
Silver Bow County, MT 108 km (67 mi) WSW earthquakes near Silver Bow County

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

Aftershocks so far

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

  1. 1.6 Western Montana
  2. 1.6 6 km NNW of Logan, Montana
  3. 1.7 5 km W of Ponderosa Pines, Montana
  4. 2.3 3 km WSW of Ponderosa Pines, Montana
  5. 2.1 3 km SW of Ponderosa Pines, Montana
  6. 2.0 11 km WSW of Radersburg, Montana
  7. 2.4 3 km WSW of Ponderosa Pines, Montana
  8. 2.0 7 km NE of Manhattan, Montana
  9. 1.5 2 km NW of Manhattan, Montana
  10. 1.7 3 km NNE of Logan, Montana
  11. 1.5 5 km SW of Manhattan, Montana
  12. 2.1 2 km WSW of Logan, Montana
  13. 1.8 5 km NW of Logan, Montana
  14. 2.2 11 km NE of Townsend, Montana
  15. 1.7 9 km WSW of Townsend, 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.