QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9ml

8 km W of Marysville, Montana

· 5.1 km deep · released about 25 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lewis and Clark County 40 kmPowell County 40 kmJefferson County 76 kmBroadwater County 85 kmGranite County 88 kmDeer Lodge County 93 kmSilver Bow County 99 kmCascade County 101 kmMeagher County 116 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 1.9 (ml)
Depth
5.1 km below the surface
Felt
no reports yet
Nearest
Lewis and Clark County, 40 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1186 days ago

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

How big was it?

This earthquake released about 25 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 620,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 440,000× the energy of this one
  3. Around the size people start to feel M 3.0 39× the energy of this one
  4. This earthquake M 1.9 about 25 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 46.7658, -112.4153. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Lewis and Clark County, MT 40 km (25 mi) S of here earthquakes near Lewis and Clark County
Powell County, MT 40 km (25 mi) ESE of here earthquakes near Powell County
Jefferson County, MT 76 km (47 mi) NNW of here earthquakes near Jefferson County
Broadwater County, MT 85 km (53 mi) NW of here earthquakes near Broadwater County
Granite County, MT 88 km (54 mi) ENE of here earthquakes near Granite County
Deer Lodge County, MT 93 km (58 mi) NE 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

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

  1. 2.2 1 km NW of East Helena, Montana
  2. 1.5 14 km ESE of Lincoln, Montana
  3. 1.7 13 km ESE of Lincoln, Montana
  4. 2.4 13 km SE of Lincoln, Montana
  5. 1.6 15 km WNW of Lincoln, Montana
  6. 1.5 2 km SSE of Lincoln, Montana
  7. 1.5 2 km SE of Lincoln, Montana
  8. 2.3 0 km ESE of Lincoln, Montana
  9. 1.9 10 km NW of Garrison, Montana
  10. 1.9 14 km SE of Lincoln, Montana
  11. 1.6 14 km SE of Lincoln, Montana
  12. 1.7 10 km NW of Marysville, Montana
  13. 2.3 14 km SE of Lincoln, Montana
  14. 2.0 19 km N of Avon, Montana
  15. 2.3 11 km ESE of Lincoln, 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 5.8 on 2017-07-06 — it released about 620,000 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.