Earthquake · reviewed by a seismologist
M 1.5ml
Earthquake near Salmon, ID
No earthquake was likely felt in Salmon in the 24 hours to 5:14 am MST (12:14 UTC). The last one was M 4.3, 102 km (64 mi) S, at 11:05 am MDT on 8 June 2025, estimated intensity II (weak) in town; 27 felt reports to USGS. Every earthquake near Salmon
This page: a magnitude 1.5 earthquake was recorded 31 km (19 mi) west-northwest of Salmon, ID, at 4:48 pm MDT on 27 October 2023 (22:48 UTC), 6.5 km deep.
USGS: Idaho-Montana border region
- When
- 4:48 pm MDT on 27 October 2023 ()
- Where
- 31 km (19 mi) west-northwest of Salmon, ID · earthquakes near Salmon
- Magnitude
- M 1.5 (ml)
- Depth
- 6.5 km below the surface
- Felt
- no reports yet
- Nearest
- Lemhi County, 47 km SE
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1112 days ago
Earthquake alerts for Salmon, ID
Get a notification in this browser when USGS records an earthquake near Salmon, 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 8 km (5 mi) from the epicentre. In Salmon, 31 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 6.2 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.
- Mineral, Virginia 2011 M 5.8 2,500,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,700,000× the energy of this one
- Around the size people start to feel M 3.0 150× the energy of this one
- This earthquake M 1.5 about 6.2 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 45.2397, -114.2837. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Lemhi County, ID | 47 km (29 mi) | SE | earthquakes near Lemhi County |
| Ravalli County, MT | 94 km (59 mi) | N | earthquakes near Ravalli County |
| Custer County, ID | 107 km (67 mi) | S | earthquakes near Custer County |
| Beaverhead County, MT | 110 km (68 mi) | E | earthquakes near Beaverhead County |
| Valley County, ID | 113 km (70 mi) | WSW | earthquakes near Valley County |
| Idaho County, ID | 114 km (71 mi) | NW | earthquakes near Idaho County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
10 earthquakes have been recorded within 50 km since this one.
- 2.5 30 km SW of Salmon, Idaho
- 1.6 52 km NNW of Challis, Idaho
- 1.7 32 km WSW of Salmon, Idaho
- 1.5 32 km WSW of Salmon, Idaho
- 2.3 62 km ENE of Yellow Pine, Idaho
- 1.6 48 km NNW of Challis, Idaho
- 1.5 6 km ESE of Salmon, Idaho
- 1.6 4 km NNE of Salmon, Idaho
- 1.8 45 km SW of Salmon, Idaho
- 2.8 25 km NNW of Salmon, 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.