Earthquake · reviewed by a seismologist
M 2.0ml
Earthquake near Helena Valley Northeast, MT
USGS: 26 km ENE of Helena Valley Northeast, Montana
- When
- 11:59 pm MST on 13 November 2017 ()
- Where
- 26 km (16 mi) ENE of Helena Valley Northeast, MT · earthquakes near Helena Valley Northeast
- Magnitude
- M 2.0 (ml)
- Depth
- 11 km below the surface
- Felt
- no reports yet
- Nearest
- Broadwater County, 54 km SSE
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 3245 days ago
A magnitude 2.0 earthquake was recorded 26 km (16 mi) ENE of Helena Valley Northeast, MT, at 11:59 pm MST on 13 November 2017 (06:59 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
Earthquakes near other towns within 30 km: Helena Valley Southeast.
How big was it?
This earthquake released about 33 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.0 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 450,000× the energy of this one
- Magna, Utah 2020 M 5.7 320,000× the energy of this one
- Around the size people start to feel M 3.0 29× the energy of this one
- This earthquake M 2.0 about 33 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:
- 6.1 The 1935 Helena, Montana Earthquakes (Mainshock) · 24 km S of this epicentre
- 5.9 2 km ENE of Helena, Montana · 36 km SW of this epicentre
- 5.9 The 1935 Helena, Montana Earthquakes (Largest Aftershock) · 33 km SSW of this epicentre
- 5.0 2 km ENE of Helena, Montana · 36 km SW 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 46.8040, -111.6418. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Broadwater County, MT | 54 km (33 mi) | SSE | earthquakes near Broadwater County |
| Meagher County, MT | 60 km (37 mi) | ESE | earthquakes near Meagher County |
| Cascade County, MT | 61 km (38 mi) | NNE | earthquakes near Cascade County |
| Lewis and Clark County, MT | 66 km (41 mi) | WNW | earthquakes near Lewis and Clark County |
| Jefferson County, MT | 82 km (51 mi) | SSW | earthquakes near Jefferson County |
| Powell County, MT | 98 km (61 mi) | W | earthquakes near Powell 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.
- 1.6 1 km SSE of South Hills, Montana
- 1.6 1 km SSE of South Hills, Montana
- 2.2 36 km SSW of Stockett, Montana
- 1.7 2 km NNW of Montana City, Montana
- 1.5 21 km NE of Townsend, Montana
- 2.2 6 km W of Helena Valley West Central, Montana
- 2.4 8 km NNE of Helena Valley Northwest, Montana
- 1.5 9 km NE of Townsend, Montana
- 2.9 11 km SW of Winston, Montana
- 2.3 2 km WNW of East Helena, Montana
- 1.6 2 km NW of Montana City, Montana
- 2.0 Western Montana
- 1.7 4 km WSW of South Hills, Montana
- 2.4 4 km NNW of Helena Valley Northeast, Montana
- 2.3 13 km WSW of Craig, 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.