M5.3 Earthquake 104 km SSW of Nikolski, Alaska — September 3, 2026
2026-09-03 18:45:39 UTC (1 hour ago) · approx. 7:45 AM UTC-11 local
Aftershock of the M6.3 mainshock.
On September 3, 2026 at 18:45 UTC, a magnitude 5.3 shallow crustal earthquake struck 104 km SSW of Nikolski, Alaska, at a depth of 10.0 km and coordinates 52.0304°, -169.2217°. This earthquake was detected by 118 seismic stations with good location accuracy and was assigned a USGS significance rating of 432, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 5.3 releases seismic energy equivalent to roughly 1 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 2.7 km — a useful intuition for the size of the slip patch on the fault.
This earthquake is part of an ongoing aftershock sequence following the magnitude 6.3 mainshock that occurred 8 hours ago 84 km SSW of Nikolski, Alaska. Since the mainshock, the USGS has recorded 63 aftershocks in this area. Aftershock activity is expected to continue for weeks to months as stresses on surrounding faults redistribute.
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
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
Earthquake Details
-169.2217°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 5.3 earthquake near Nikolski, Alaska?
The magnitude 5.3 earthquake that struck 104 km SSW of Nikolski, Alaska on September 3, 2026 at 18:45 UTC had a depth of 10.0 km. For context, this was a moderate earthquake that could be widely felt.
Where did the earthquake occur?
The earthquake epicenter was located at 52.0304°, -169.2217°, which is 104 km SSW of Nikolski, Alaska. View all earthquakes in Alaska.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.3 earthquakes can continue for days to weeks and gradually diminish over time.
Is this the same earthquake as the M6.3 one earlier?
No. This magnitude 5.3 earthquake is an aftershock of the larger magnitude 6.3 mainshock that occurred earlier 84 km SSW of Nikolski, Alaska. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
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 5.3 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us7000te2m). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, September 3, 2026). M5.3 Earthquake 104 km SSW of Nikolski, Alaska — September 3, 2026. Retrieved September 3, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000te2m/