M3.1 Earthquake 75 km WSW of Karluk, Alaska — September 23, 2026
2026-09-23 13:30:25 UTC (12 hours ago) · approx. 3:30 AM UTC-10 local
On September 23, 2026 at 13:30 UTC, a magnitude 3.1 shallow crustal earthquake struck 75 km WSW of Karluk, Alaska, at a depth of 51.3 km and coordinates 57.2020°, -155.5080°.
Physical scale: An earthquake of magnitude 3.1 releases seismic energy equivalent to roughly 674 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 83 m — a useful intuition for the size of the slip patch on the fault.
Earthquake Details
-155.5080°E
Technical Information
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Common Questions
How strong was the magnitude 3.1 earthquake near Karluk, Alaska?
The magnitude 3.1 earthquake that struck 75 km WSW of Karluk, Alaska on September 23, 2026 at 13:30 UTC had a depth of 51.3 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 3.1 earthquakes can continue for several days and gradually diminish over time.
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Understanding This Data
Magnitude 3.1 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: aka2026swmvfb). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, September 23, 2026). M3.1 Earthquake 75 km WSW of Karluk, Alaska — September 23, 2026. Retrieved September 23, 2026 from https://www.earthquaketracker.org/earthquakes/event/aka2026swmvfb/