QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

Earthquake near Ketchum, ID

No earthquake was likely felt in Ketchum in the 24 hours to 4:50 pm MST (23:50 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 1.7 earthquake was recorded 37 km (23 mi) north of Ketchum, ID, at 6:17 pm MDT on 19 May 2018 (00:17 UTC), 8.9 km deep.

USGS: 28 km S of Clayton, Idaho

6:17 pm MDT, May 19, 2018 · · 8.9 km deep · released about 10 lb of TNT

Every earthquake near Ketchum Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Custer County 33 kmCamas County 63 kmBlaine County 78 kmBoise County 103 kmButte County 106 kmElmore County 108 kmLemhi County 111 kmLincoln County 115 kmGooding County 119 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
6:17 pm MDT on 19 May 2018 ()
Where
37 km (23 mi) north of Ketchum, ID · earthquakes near Ketchum
Idaho today
every earthquake in Idaho in the last 24 hours
Magnitude
M 1.7 (ml)
Depth
8.9 km below the surface
Felt
no reports yet
Nearest
Custer County, 33 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3096 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 8 km (5 mi) from the epicentre. In Ketchum, 37 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 10 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,100,000× the energy of this one
  3. Around the size people start to feel M 3.0 95× the energy of this one
  4. This earthquake M 1.7 about 10 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:

  1. 6.9 The 1983 Borah Peak Earthquake, Idaho · 46 km E of this epicentre
  2. 5.5 22 km E of Clayton, Idaho · 39 km NE of this epicentre
  3. 5.4 29 km NW of Mackay, Idaho · 42 km E of this epicentre
  4. 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 44.0070, -114.4253. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Custer County, ID 33 km (20 mi) NNE earthquakes near Custer County
Camas County, ID 63 km (39 mi) SSW earthquakes near Camas County
Blaine County, ID 78 km (48 mi) SSE earthquakes near Blaine County
Boise County, ID 103 km (64 mi) W earthquakes near Boise County
Butte County, ID 106 km (66 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

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

  1. 1.6 24 km E of Clayton, Idaho
  2. 1.6 19 km NW of Clayton, Idaho
  3. 2.5 9 km SSE of Clayton, Idaho
  4. 2.1 25 km SSW of Clayton, Idaho
  5. 1.6 34 km NW of Mackay, Idaho
  6. 1.6 34 km SE of Stanley, Idaho
  7. 1.9 35 km ESE of Clayton, Idaho
  8. 1.8 13 km NNE of Clayton, Idaho
  9. 2.1 10 km W of Clayton, Idaho
  10. 1.7 27 km S of Clayton, Idaho
  11. 2.2 12 km W of Clayton, Idaho
  12. 2.1 21 km NNW of Clayton, Idaho
  13. 1.9 15 km W of Clayton, Idaho
  14. 1.6 13 km W of Clayton, Idaho
  15. 2.4 13 km WNW 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

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.