Earthquake · reviewed by a seismologist
M 1.9ml
14 km WSW of Stanley, Idaho
Yes. A magnitude 1.9 earthquake was recorded 14 km WSW of Stanley, Idaho, at 2:49 pm MDT on 20 August 2020 (20:49 UTC), 12 km deep.
- When
- Idaho today
- every earthquake in Idaho in the last 24 hours
- Magnitude
- M 1.9 (ml)
- Depth
- 12 km below the surface
- Felt
- no reports yet
- Nearest
- Boise County, 53 km WSW
- Nearest mapped fault
- Sawtooth fault, 6 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 2273 days ago
Earthquake alerts for Challis, ID
Get a notification in this browser when USGS records an earthquake near Challis, 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. 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 18 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 840,000× the energy of this one
- Magna, Utah 2020 M 5.7 600,000× the energy of this one
- Around the size people start to feel M 3.0 53× the energy of this one
- This earthquake M 1.9 about 18 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 6.5 on 2020-03-31 — about 9,400,000 times the energy of this one.
Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:
- 6.1 37 km N of Stanley, Idaho · 45 km NNE of this epicentre
- 6.0 44 km NNW of Stanley, Idaho · 46 km N 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 44.1897, -115.1197. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Boise County, ID | 53 km (33 mi) | WSW | earthquakes near Boise County |
| Custer County, ID | 70 km (43 mi) | E | earthquakes near Custer County |
| Camas County, ID | 81 km (51 mi) | SSE | earthquakes near Camas County |
| Valley County, ID | 84 km (52 mi) | NNW | earthquakes near Valley County |
| Elmore County, ID | 93 km (58 mi) | SSW | earthquakes near Elmore County |
| Gem County, ID | 103 km (64 mi) | W | earthquakes near Gem 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.
- 2.0 27 km NW of Stanley, Idaho
- 2.2 11 km WNW of Stanley, Idaho
- 1.9 27 km NW of Stanley, Idaho
- 2.0 25 km NW of Stanley, Idaho
- 2.2 27 km NW of Stanley, Idaho
- 2.0 20 km WNW of Stanley, Idaho
- 2.8 37 km NW of Stanley, Idaho
- 2.3 23 km NW of Stanley, Idaho
- 1.7 22 km NW of Stanley, Idaho
- 2.3 14 km SW of Stanley, Idaho
- 2.2 13 km SW of Stanley, Idaho
- 2.2 26 km NW of Stanley, Idaho
- 2.1 29 km NW of Stanley, Idaho
- 1.9 18 km WNW of Stanley, Idaho
- 1.9 20 km WNW of Stanley, 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.