QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5md

Earthquake near Challis, ID

No earthquake was likely felt in Challis in the 24 hours to 5:21 pm MST (00:21 UTC). The last one was M 2.0, 9 km (6 mi) SSW, at 1:32 am MDT on 17 August 2026, estimated intensity II (weak) in town. Every earthquake near Challis

This page: a magnitude 1.5 earthquake was recorded 45 km (28 mi) south-southeast of Challis, ID, at 7:31 am MST on 11 January 2020 (14:31 UTC), 8.0 km deep.

USGS: Idaho-Montana border region

7:31 am MST, Jan 11, 2020 · · 8.0 km deep · released about 5.6 lb of TNT

Every earthquake near Challis Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Custer County 26 kmButte County 82 kmBlaine County 83 kmLemhi County 87 kmCamas County 96 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
7:31 am MST on 11 January 2020 ()
Where
45 km (28 mi) south-southeast of Challis, ID · earthquakes near Challis
Magnitude
M 1.5 (md)
Depth
8.0 km below the surface
Felt
no reports yet
Nearest
Custer County, 26 km WNW
Nearest mapped fault
Lost River fault, 9 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2496 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 6 km (4 mi) from the epicentre. In Challis, 45 km away, the estimate is intensity I (not felt). 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.

Where

Epicentre 44.1443, -113.9778. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Custer County, ID 26 km (16 mi) WNW earthquakes near Custer County
Butte County, ID 82 km (51 mi) SE earthquakes near Butte County
Blaine County, ID 83 km (52 mi) S earthquakes near Blaine County
Lemhi County, ID 87 km (54 mi) N earthquakes near Lemhi County
Camas County, ID 96 km (59 mi) SW earthquakes near Camas County
Beaverhead County, MT 140 km (87 mi) NE earthquakes near Beaverhead County

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

Aftershocks so far

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

  1. 1.6 22 km SE of Challis, Idaho
  2. 1.9 15 km SW of Clayton, Idaho
  3. 1.5 10 km SE of Challis, Idaho
  4. 1.9 17 km SE of Challis, Idaho
  5. 1.9 11 km SE of Challis, Idaho
  6. 2.3 13 km SW of Clayton, Idaho
  7. 1.6 20 km SE of Challis, Idaho
  8. 2.1 17 km SE of Challis, Idaho
  9. 1.7 12 km SSW of Clayton, Idaho
  10. 1.6 14 km ENE of Challis, Idaho
  11. 2.2 19 km ESE of Challis, Idaho
  12. 1.8 19 km E of Challis, Idaho
  13. 1.8 11 km ESE of Challis, Idaho
  14. 2.4 14 km SSE of Clayton, Idaho
  15. 2.4 26 km ESE of Challis, Idaho

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

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