M4.2 Earthquake 66 km WNW of Lake Louise, Alaska — September 10, 2026
2026-09-10 05:18:08 UTC (2026-09-10) · approx. 7:18 PM UTC-10 local
Felt by 251 people across surrounding communities. Maximum shaking intensity MMI 4.0 (moderate).
On September 10, 2026 at 05:18 UTC, a magnitude 4.2 shallow crustal earthquake struck 66 km WNW of Lake Louise, Alaska, at a depth of 15.8 km and coordinates 62.5060°, -147.7420°. The earthquake was reported felt by 251 peopleacross surrounding communities, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 4.0 (moderate). This earthquake was detected by 223 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 354, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 4.2 releases seismic energy equivalent to roughly 30 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 476 m — a useful intuition for the size of the slip patch on the fault.
The epicenter is located in Alaska, a region characterized by Pacific Plate subduction beneath the North American Plate, producing frequent megathrust and crustal earthquakes along the Aleutian arc. The nearest mapped fault system is the Aleutian megathrust. View all earthquakes in Alaska.
Learn more: Magnitude scale · Aftershock sequences
What the Shaking Felt Like
At MMI 4.0 (moderate), people in the most strongly affected areas would have experienced: Mild shaking, similar to a passing truck. Hanging objects swing. Glasses and dishes may rattle. Not commonly felt outdoors.
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 251 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
-147.7420°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.2 earthquake near Lake Louise, Alaska?
The magnitude 4.2 earthquake that struck 66 km WNW of Lake Louise, Alaska on September 10, 2026 at 05:18 UTC had a depth of 15.8 km. It was felt by 251 people with maximum shaking intensity of MMI 4.0 (moderate). For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 62.5060°, -147.7420°, which is 66 km WNW of Lake Louise, Alaska. View all earthquakes in Alaska.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.2 earthquakes can continue for several days and gradually diminish over time.
Has Alaska had earthquakes this big before?
The largest recorded earthquake in Alaska was the M9.2 Great Alaska earthquake of March 27, 1964. Today's magnitude 4.2 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: aka2026rxwdbw). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, September 10, 2026). M4.2 Earthquake 66 km WNW of Lake Louise, Alaska — September 10, 2026. Retrieved September 20, 2026 from https://www.earthquaketracker.org/earthquakes/event/aka2026rxwdbw/