Earthquake · reviewed by a seismologist
M 2.3ml
Earthquake near Ketchum, ID
No earthquake was likely felt in Ketchum in the 24 hours to 11:12 pm MST (06:12 UTC). The last one was M 4.3, 68 km (43 mi) NNE, at 11:05 am MDT on 8 June 2025, estimated intensity II (weak) in town; 27 felt reports to USGS. Every earthquake near Ketchum
This page: a magnitude 2.3 earthquake was recorded 36 km (22 mi) north of Ketchum, ID, at 8:28 am MDT on 17 October 2020 (14:28 UTC), 10 km deep. 1 person has reported feeling it to USGS.
USGS: 28 km S of Clayton, Idaho
- When
- 8:28 am MDT on 17 October 2020 ()
- Where
- 36 km (22 mi) north of Ketchum, ID · earthquakes near Ketchum
- Idaho today
- every earthquake in Idaho in the last 24 hours
- Magnitude
- M 2.3 (ml)
- Depth
- 10 km below the surface
- Felt
- 1 report · strongest reported intensity II
- Nearest
- Custer County, 33 km NNE
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 2144 days ago
Earthquake alerts for Ketchum, ID
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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 17 km (11 mi) from the epicentre. In Ketchum, 36 km away, the estimate is intensity II (weak). 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 85 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 180,000× the energy of this one
- Magna, Utah 2020 M 5.7 130,000× the energy of this one
- Around the size people start to feel M 3.0 11× the energy of this one
- This earthquake M 2.3 about 85 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
No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.
Before 2016, the USGS record lists 4 earthquakes of M5 or more within 50 km:
- 6.9 The 1983 Borah Peak Earthquake, Idaho · 45 km E of this epicentre
- 5.5 22 km E of Clayton, Idaho · 39 km NE of this epicentre
- 5.4 29 km NW of Mackay, Idaho · 41 km ENE of this epicentre
- 5.4 23 km E of Clayton, Idaho · 36 km NE 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 43.9984, -114.4126. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Custer County, ID | 33 km (21 mi) | NNE | earthquakes near Custer County |
| Camas County, ID | 62 km (39 mi) | SSW | earthquakes near Camas County |
| Blaine County, ID | 77 km (48 mi) | SSE | earthquakes near Blaine County |
| Boise County, ID | 104 km (65 mi) | W | earthquakes near Boise County |
| Butte County, ID | 105 km (65 mi) | ESE | earthquakes near Butte County |
| Elmore County, ID | 108 km (67 mi) | SW | earthquakes near Elmore County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
42 earthquakes have been recorded within 50 km since this one.
- 2.6 24 km NE of Stanley, Idaho
- 2.5 25 km NE of Stanley, Idaho
- 2.0 14 km ENE of Stanley, Idaho
- 2.0 15 km ENE of Stanley, Idaho
- 2.9 14 km ENE of Stanley, Idaho
- 1.9 15 km ENE of Stanley, Idaho
- 1.8 11 km NE of Stanley, Idaho
- 1.8 southern Idaho
- 2.1 18 km S of Stanley, Idaho
- 2.0 4 km NNE of Stanley, Idaho
- 2.3 13 km NE of Stanley, Idaho
- 2.6 10 km NE of Stanley, Idaho
- 2.1 15 km ENE of Stanley, Idaho
- 2.4 19 km S of Stanley, Idaho
- 3.2 14 km S 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.