QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6ml

6 km SE of Craig, Montana

· 7.4 km deep · released about 8.1 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lewis and Clark County 38 kmCascade County 52 kmPowell County 82 kmBroadwater County 84 kmMeagher County 89 kmTeton County 92 kmJefferson County 102 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 1.6 (ml)
Depth
7.4 km below the surface
Felt
no reports yet
Nearest
Lewis and Clark County, 38 km WNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 517 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 8.1 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,900,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,300,000× the energy of this one
  3. Around the size people start to feel M 3.0 120× the energy of this one
  4. This earthquake M 1.6 about 8.1 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 47.0333, -111.8937. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Lewis and Clark County, MT 38 km (24 mi) ESE of here earthquakes near Lewis and Clark County
Cascade County, MT 52 km (32 mi) SW of here earthquakes near Cascade County
Powell County, MT 82 km (51 mi) ENE of here earthquakes near Powell County
Broadwater County, MT 84 km (52 mi) NNW of here earthquakes near Broadwater County
Meagher County, MT 89 km (55 mi) NW of here earthquakes near Meagher County
Teton County, MT 92 km (57 mi) SSE of here earthquakes near Teton County

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

Aftershocks so far

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

  1. 1.5 16 km NE of Helena Valley Northwest, Montana
  2. 1.6 14 km SSE of Craig, Montana
  3. 2.4 21 km SSE of Craig, Montana
  4. 2.0 32 km ENE of Helena Valley Northeast, Montana
  5. 2.0 20 km NNE of Helena Valley Northeast, Montana
  6. 1.5 31 km ENE of Helena Valley Northeast, Montana
  7. 2.0 19 km E of Lincoln, Montana
  8. 1.7 14 km NNW of Winston, Montana
  9. 1.6 18 km E of Lincoln, Montana
  10. 1.5 3 km SE of Helena Valley West Central, 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 4.3 on 2016-01-30 — it released about 12,000 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.