QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

23 km WSW of Craig, Montana

· 3.6 km deep · released about 13 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lewis and Clark County 14 kmPowell County 54 kmCascade County 76 kmTeton County 88 kmBroadwater County 97 kmJefferson County 101 kmGranite County 113 kmMeagher County 113 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 1.8 (ml)
Depth
3.6 km below the surface
Felt
no reports yet
Nearest
Lewis and Clark County, 14 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1968 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 13 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 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 810,000× the energy of this one
  3. Around the size people start to feel M 3.0 72× the energy of this one
  4. This earthquake M 1.8 about 13 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 47.0245, -112.2662. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Lewis and Clark County, MT 14 km (9 mi) SE of here earthquakes near Lewis and Clark County
Powell County, MT 54 km (34 mi) ENE of here earthquakes near Powell County
Cascade County, MT 76 km (48 mi) WSW of here earthquakes near Cascade County
Teton County, MT 88 km (55 mi) S of here earthquakes near Teton County
Broadwater County, MT 97 km (60 mi) NW of here earthquakes near Broadwater County
Jefferson County, MT 101 km (63 mi) N of here earthquakes near Jefferson County

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

Aftershocks so far

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

  1. 2.0 9 km E of Lincoln, Montana
  2. 1.8 11 km E of Lincoln, Montana
  3. 1.5 11 km E of Lincoln, Montana
  4. 1.8 16 km E of Lincoln, Montana
  5. 1.5 12 km E of Lincoln, Montana
  6. 2.4 15 km ESE of Lincoln, Montana
  7. 1.7 10 km N of Elliston, Montana
  8. 1.8 8 km SSE of Marysville, Montana
  9. 1.9 13 km ESE of Lincoln, Montana
  10. 1.6 3 km SW of Helena Valley Northwest, Montana
  11. 1.6 5 km SSE of Lincoln, Montana
  12. 1.8 12 km ESE of Lincoln, Montana
  13. 2.0 5 km SSE of Lincoln, Montana
  14. 2.8 7 km SSE of Lincoln, Montana
  15. 3.3 6 km SSE 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 1,100,000 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.