Earthquake · reviewed by a seismologist
M 1.6ml
Earthquake near Challis, ID
No earthquake was likely felt in Challis in the 24 hours to 11:00 pm MST (06:00 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 1.6 earthquake was recorded 46 km (29 mi) west-southwest of Challis, ID, at 9:07 am MDT on 6 October 2021 (15:07 UTC), 6.3 km deep.
USGS: 19 km NE of Stanley, Idaho
- When
- 9:07 am MDT on 6 October 2021 ()
- Where
- 46 km (29 mi) west-southwest of Challis, ID · earthquakes near Challis
- Idaho today
- every earthquake in Idaho in the last 24 hours
- Magnitude
- M 1.6 (ml)
- Depth
- 6.3 km below the surface
- Felt
- no reports yet
- Nearest
- Custer County, 40 km E
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1863 days ago
Earthquake alerts for Challis, ID
Get a notification in this browser when USGS records an earthquake near Challis, ID. No account or email needed.
Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
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 9 km (6 mi) from the epicentre. In Challis, 46 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 7.8 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.
- Mineral, Virginia 2011 M 5.8 1,900,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,400,000× the energy of this one
- Around the size people start to feel M 3.0 120× the energy of this one
- This earthquake M 1.6 about 7.8 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.
For this area
The largest earthquake within 50 km since 2016 was M 6.5 on 2020-03-31 — about 22,000,000 times the energy of this one.
Before 2016, the USGS record lists 3 earthquakes of M5 or more within 50 km:
- 6.1 37 km N of Stanley, Idaho · 28 km NNW of this epicentre
- 6.0 44 km NNW of Stanley, Idaho · 41 km NW of this epicentre
- 5.1 9 km SE of Challis, Idaho · 49 km ENE of this epicentre
Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.
Where
Epicentre 44.3272, -114.7552. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Custer County, ID | 40 km (25 mi) | E | earthquakes near Custer County |
| Boise County, ID | 85 km (53 mi) | WSW | earthquakes near Boise County |
| Valley County, ID | 90 km (56 mi) | NW | earthquakes near Valley County |
| Camas County, ID | 92 km (57 mi) | S | earthquakes near Camas County |
| Lemhi County, ID | 96 km (60 mi) | NE | earthquakes near Lemhi County |
| Elmore County, ID | 119 km (74 mi) | SSW | earthquakes near Elmore 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.
- 1.8 18 km WNW of Stanley, Idaho
- 2.2 24 km WNW of Stanley, Idaho
- 2.1 37 km NW of Stanley, Idaho
- 2.3 12 km NW of Stanley, Idaho
- 2.3 20 km WNW of Stanley, Idaho
- 2.2 13 km NW of Stanley, Idaho
- 2.7 16 km NW of Stanley, Idaho
- 2.7 16 km NW of Stanley, Idaho
- 2.4 southern Idaho
- 2.5 10 km WNW of Stanley, Idaho
- 2.8 24 km WNW of Stanley, Idaho
- 2.2 38 km NW of Stanley, Idaho
- 2.3 27 km NW of Stanley, Idaho
- 2.4 27 km WNW of Stanley, Idaho
- 2.6 14 km NW of Stanley, 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
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.