M3.6 Earthquake 112 km SE of Atka, Alaska — September 18, 2026
2026-09-18 09:23:44 UTC (11 hours ago) · approx. 9:23 PM UTC-12 local
On September 18, 2026 at 09:23 UTC, a magnitude 3.6 shallow crustal earthquake struck 112 km SE of Atka, Alaska, at a depth of 0.0 km and coordinates 51.3640°, -173.2780°.
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.
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
-173.2780°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 3.6 earthquake near Atka, Alaska?
The magnitude 3.6 earthquake that struck 112 km SE of Atka, Alaska on September 18, 2026 at 09:23 UTC had a depth of 0.0 km. For context, this was a minor earthquake typically detected only by instruments.
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.
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Understanding This Data
Magnitude 3.6 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: aka2026smympm). 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 112 km SE of Atka, Alaska — September 18, 2026. Retrieved September 18, 2026 from https://www.earthquaketracker.org/earthquakes/event/aka2026smympm/