QuakeIndex

Earthquake · reviewed by a seismologist

M 2.7ml

11 km NW of Harrison, Montana

· 11 km deep · released about 340 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Jefferson County 41 kmMadison County 50 kmSilver Bow County 62 kmGallatin County 63 kmBroadwater County 69 kmDeer Lodge County 104 kmBeaverhead County 106 kmPark County 111 kmMeagher County 117 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 2.7 (ml)
Depth
11 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
Jefferson County, 41 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3023 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 1 person has reported feeling it to USGS.

How big was it?

This earthquake released about 340 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 45,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 32,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.8× the energy of this one
  4. This earthquake M 2.7 about 340 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.

Where

Epicentre 45.7713, -111.8864. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Jefferson County, MT 41 km (26 mi) SSE of here earthquakes near Jefferson County
Madison County, MT 50 km (31 mi) N of here earthquakes near Madison County
Silver Bow County, MT 62 km (38 mi) ESE of here earthquakes near Silver Bow County
Gallatin County, MT 63 km (39 mi) WNW of here earthquakes near Gallatin County
Broadwater County, MT 69 km (43 mi) SSW of here earthquakes near Broadwater County
Deer Lodge County, MT 104 km (64 mi) ESE of here earthquakes near Deer Lodge 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 1 km W of Manhattan, Montana
  2. 2.3 1 km WNW of Manhattan, Montana
  3. 1.6 1 km WNW of Manhattan, Montana
  4. 2.0 1 km W of Manhattan, Montana
  5. 2.2 2 km WNW of Manhattan, Montana
  6. 2.2 2 km W of Manhattan, Montana
  7. 1.8 1 km WNW of Manhattan, Montana
  8. 1.9 1 km W of Manhattan, Montana
  9. 1.8 1 km WNW of Manhattan, Montana
  10. 1.5 2 km SW of Manhattan, Montana
  11. 1.7 0 km W of Manhattan, Montana
  12. 1.8 2 km WNW of Manhattan, Montana
  13. 2.1 1 km W of Manhattan, Montana
  14. 2.0 2 km WNW of Manhattan, Montana
  15. 2.4 1 km WNW of Manhattan, 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.0 on 2016-09-03 — it released about 99 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.