M4.0 Earthquake 85 km SSW of Nikolski, Alaska — September 19, 2026
2026-09-19 12:44:03 UTC (2026-09-19) · approx. 1:44 AM UTC-11 local
On September 19, 2026 at 12:44 UTC, a magnitude 4.0 shallow crustal earthquake struck 85 km SSW of Nikolski, Alaska, at a depth of 37.6 km and coordinates 52.2629°, -169.4516°.
Physical scale: An earthquake of magnitude 4.0 releases seismic energy equivalent to roughly 15 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 347 m — a useful intuition for the size of the slip patch on the fault.
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
-169.4516°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.0 earthquake near Nikolski, Alaska?
The magnitude 4.0 earthquake that struck 85 km SSW of Nikolski, Alaska on September 19, 2026 at 12:44 UTC had a depth of 37.6 km. For context, this was a light earthquake commonly felt near the epicenter.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.0 earthquakes can continue for several days and gradually diminish over time.
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Understanding This Data
Magnitude 4.0 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us7000tikp). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, September 19, 2026). M4.0 Earthquake 85 km SSW of Nikolski, Alaska — September 19, 2026. Retrieved October 1, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000tikp/