QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

18 km SE of Cascade, Idaho

Yes. A magnitude 1.7 earthquake was recorded 18 km SE of Cascade, Idaho, 96 km (60 mi) NNE of Boise City, ID, at 7:50 pm MDT on 19 September 2020 (01:50 UTC), 7.2 km deep.

96 km (60 mi) NNE of Boise City, ID

· 7.2 km deep · released about 9.6 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Boise County 49 kmValley County 52 kmGem County 59 kmAdams County 70 kmWashington County 75 kmPayette County 85 kmCanyon County 111 kmAda County 112 kmElmore County 118 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 1.7 (ml)
Depth
7.2 km below the surface
Felt
no reports yet
Nearest
Boise County, 49 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2243 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 10 km (6 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 9.6 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 1,600,000× 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 99× the energy of this one
  4. This earthquake M 1.7 about 9.6 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 44.4182, -115.8573. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Boise County, ID 49 km (31 mi) SSE earthquakes near Boise County
Valley County, ID 52 km (32 mi) NNE earthquakes near Valley County
Gem County, ID 59 km (36 mi) SW earthquakes near Gem County
Adams County, ID 70 km (43 mi) NW earthquakes near Adams County
Washington County, ID 75 km (46 mi) W earthquakes near Washington County
Payette County, ID 85 km (53 mi) WSW earthquakes near Payette County

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

Aftershocks so far

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

  1. 2.1 6 km NNE of Smiths Ferry, Idaho
  2. 2.4 7 km W of Smiths Ferry, Idaho
  3. 2.1 39 km N of Lowman, Idaho
  4. 2.2 6 km N of Smiths Ferry, Idaho
  5. 3.1 6 km NNW of Smiths Ferry, Idaho
  6. 2.0 6 km WNW of Smiths Ferry, Idaho
  7. 2.1 2 km N of Smiths Ferry, Idaho
  8. 1.8 38 km N of Lowman, Idaho
  9. 2.2 41 km NW of Stanley, Idaho
  10. 2.2 7 km W of Smiths Ferry, Idaho
  11. 2.1 4 km NNW of Cascade, Idaho
  12. 2.2 31 km NNE of Lowman, Idaho
  13. 1.7 8 km WNW of Smiths Ferry, Idaho
  14. 1.7 14 km NW of Cascade, Idaho
  15. 1.9 24 km E 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.