M3.6 Earthquake 5 km NW of Black Eagle, Montana — September 18, 2026
2026-09-18 13:40:42 UTC (2 hours ago) · approx. 6:40 AM UTC-7 local
Felt by 140 people across surrounding communities.
On September 18, 2026 at 13:40 UTC, a magnitude 3.6 shallow crustal earthquake struck 5 km NW of Black Eagle, Montana, at a depth of 27.7 km and coordinates 47.5572°, -111.3244°. The earthquake was reported felt by 140 peopleacross surrounding communities, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 3.4 (light). This earthquake was detected by 28 seismic stations with good location accuracy and was assigned a USGS significance rating of 247, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 3.6 releases seismic energy equivalent to roughly 3.8 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 184 m — a useful intuition for the size of the slip patch on the fault.
The epicenter is located in Montana, a region characterized by the Intermountain Seismic Belt, a diffuse zone of crustal deformation between the stable craton and the Basin and Range. View all earthquakes in Montana.
Learn more: Magnitude scale · Aftershock sequences
ShakeMap — predicted shaking intensity
Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.
Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 140 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.
Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report
Earthquake Details
-111.3244°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 3.6 earthquake near Black Eagle, Montana?
The magnitude 3.6 earthquake that struck 5 km NW of Black Eagle, Montana on September 18, 2026 at 13:40 UTC had a depth of 27.7 km. It was felt by 140 people with maximum shaking intensity of MMI 3.4 (light). For context, this was a minor earthquake typically detected only by instruments.
Where did the earthquake occur?
The earthquake epicenter was located at 47.5572°, -111.3244°, which is 5 km NW of Black Eagle, Montana. View all earthquakes in Montana.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 3.6 earthquakes can continue for several days and gradually diminish over time.
Has Montana had earthquakes this big before?
The largest recorded earthquake in Montana was the M7.3 Hebgen Lake earthquake of August 17, 1959. Today's magnitude 3.6 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us7000tiax). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, September 18, 2026). M3.6 Earthquake 5 km NW of Black Eagle, Montana — September 18, 2026. Retrieved September 18, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000tiax/