Earthquake · reviewed by a seismologist
M 1.8ml
Earthquake near Evergreen, MT
USGS: 3 km W of Evergreen, Montana
- When
- 7:38 am MDT on 31 August 2017 ()
- Where
- 3 km (2 mi) W of Evergreen, MT · earthquakes near Evergreen
- Magnitude
- M 1.8 (ml)
- Depth
- 9.0 km below the surface
- Felt
- no reports yet
- Nearest
- Flathead County, 21 km ENE
- Nearest mapped fault
- Mission fault, 8 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 3320 days ago
A magnitude 1.8 earthquake was recorded 3 km (2 mi) W of Evergreen, MT, at 7:38 am MDT on 31 August 2017 (13:38 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
Earthquakes near other towns within 30 km: Kalispell, Somers, Columbia Falls, Whitefish, Lakeside, Bigfork.
How big was it?
This earthquake released about 13 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 1,200,000× the energy of this one
- Magna, Utah 2020 M 5.7 840,000× the energy of this one
- Around the size people start to feel M 3.0 75× the energy of this one
- This earthquake M 1.8 about 13 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 one earthquake of M5 or more within 50 km:
- 5.5 Western Montana · 46 km ESE 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 48.2243, -114.3172. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Flathead County, MT | 21 km (13 mi) | ENE | earthquakes near Flathead County |
| Lake County, MT | 67 km (42 mi) | SSE | earthquakes near Lake County |
| Sanders County, MT | 83 km (51 mi) | SW | earthquakes near Sanders County |
| Lincoln County, MT | 92 km (57 mi) | WNW | earthquakes near Lincoln County |
| Glacier County, MT | 111 km (69 mi) | ENE | earthquakes near Glacier County |
| Shoshone County, ID | 152 km (95 mi) | SW | earthquakes near Shoshone County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
54 earthquakes have been recorded within 50 km since this one.
- 1.5 8 km ESE of Woods Bay, Montana
- 1.6 3 km NNE of Somers, Montana
- 2.0 1 km ENE of Columbia Falls, Montana
- 1.6 Western Montana
- 2.1 8 km NNW of Bigfork, Montana
- 1.7 11 km NW of Batavia, Montana
- 2.9 4 km N of Elmo, Montana
- 1.6 12 km NNW of Batavia, Montana
- 2.5 6 km WNW of Bear Dance, Montana
- 1.6 4 km ESE of Rollins, Montana
- 1.6 13 km WNW of Marion, Montana
- 2.1 16 km NNE of Swan Lake, Montana
- 2.1 10 km SW of Whitefish, Montana
- 1.7 3 km E of Forest Hill Village, Montana
- 1.6 13 km E of Martin City, Montana
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.