QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8ml

20 km SE of Cascade, Idaho

Yes. A magnitude 2.8 earthquake was recorded 20 km SE of Cascade, Idaho, 93 km (58 mi) NNE of Boise City, ID, at 6:20 am MDT on 18 October 2025 (12:20 UTC), 12 km deep. 1 person has reported feeling it to USGS.

93 km (58 mi) NNE of Boise City, ID

· 12 km deep · released about 480 lb of TNT

10 km30 km60 km120 km N Boise County 46 kmValley County 55 kmGem County 57 kmAdams County 72 kmWashington County 75 kmPayette County 84 kmAda County 109 kmCanyon County 109 kmElmore County 115 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
Idaho today
every earthquake in Idaho in the last 24 hours
Magnitude
M 2.8 (ml)
Depth
12 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
Boise County, 46 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 307 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 25 km (16 mi) from the epicentre. 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 480 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 32,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 22,000× the energy of this one
  3. Around the size people start to feel M 3.0 2× the energy of this one
  4. This earthquake M 2.8 about 480 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 4.9 on 2024-02-26 — about 1,400 times the energy of this one.

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 44.3923, -115.8511. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Boise County, ID 46 km (29 mi) SSE earthquakes near Boise County
Valley County, ID 55 km (34 mi) NNE earthquakes near Valley County
Gem County, ID 57 km (35 mi) SW earthquakes near Gem County
Adams County, ID 72 km (45 mi) NW earthquakes near Adams County
Washington County, ID 75 km (47 mi) W earthquakes near Washington County
Payette County, ID 84 km (52 mi) WSW earthquakes near Payette County

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

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

  1. 2.9 30 km N of Lowman, Idaho
  2. 2.7 28 km N of Lowman, Idaho
  3. 1.6 30 km N of Lowman, Idaho
  4. 1.7 12 km WNW of Cascade, Idaho
  5. 1.8 6 km N of Smiths Ferry, 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.