Earthquake · reviewed by a seismologist
M 1.6ml
Earthquake near Ketchum, ID
No earthquake was likely felt in Ketchum in the 24 hours to 10:15 pm MST (05:15 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 1.6 earthquake was recorded 41 km (25 mi) northwest of Ketchum, ID, at 3:14 am MDT on 22 September 2018 (09:14 UTC), 14 km deep.
USGS: 34 km SE of Stanley, Idaho
- When
- 3:14 am MDT on 22 September 2018 ()
- Where
- 41 km (25 mi) northwest of Ketchum, ID · earthquakes near Ketchum
- Idaho today
- every earthquake in Idaho in the last 24 hours
- Magnitude
- M 1.6 (ml)
- Depth
- 14 km below the surface
- Felt
- no reports yet
- Nearest
- Custer County, 49 km NE
- Nearest mapped fault
- Sawtooth fault, 13 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 2970 days ago
Earthquake alerts for Ketchum, ID
Get a notification in this browser when USGS records an earthquake near Ketchum, 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 it was probably too small to be felt, even directly above it. In Ketchum, 41 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 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.
- Mineral, Virginia 2011 M 5.8 1,900,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,300,000× 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 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.
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 since 1900 lists no earthquake of M5 or more within 50 km.
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 43.9640, -114.6862. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Custer County, ID | 49 km (30 mi) | NE | earthquakes near Custer County |
| Camas County, ID | 52 km (32 mi) | S | earthquakes near Camas County |
| Boise County, ID | 82 km (51 mi) | W | earthquakes near Boise County |
| Blaine County, ID | 86 km (54 mi) | SE | earthquakes near Blaine County |
| Elmore County, ID | 89 km (56 mi) | SW | earthquakes near Elmore County |
| Gooding County, ID | 111 km (69 mi) | S | earthquakes near Gooding County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
34 earthquakes have been recorded within 50 km since this one.
- 2.5 20 km SSW of Clayton, Idaho
- 1.9 13 km SE of Stanley, Idaho
- 2.1 14 km SE of Stanley, Idaho
- 2.4 17 km SSE of Clayton, Idaho
- 2.8 13 km SSE of Clayton, Idaho
- 1.8 25 km SSW of Clayton, Idaho
- 2.4 25 km SSW of Clayton, Idaho
- 1.7 7 km N of Stanley, Idaho
- 2.1 8 km SE of Clayton, Idaho
- 2.0 7 km N of Stanley, Idaho
- 1.5 11 km W of Clayton, Idaho
- 1.6 11 km W of Clayton, Idaho
- 1.7 southern Idaho
- 1.8 15 km SSE of Clayton, Idaho
- 1.6 19 km NW of Clayton, 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.