M3.1 Earthquake 95 km E of Nikolski, Alaska — March 18, 2026
2026-03-18 17:52:12 UTC (2026-03-18) · approx. 6:52 AM UTC-11 local
On March 18, 2026 at 17:52 UTC, a magnitude 3.1 shallow crustal earthquake struck 95 km E of Nikolski, Alaska, at a depth of 7.7 km and coordinates 52.7990°, -167.4681°.
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.
This earthquake is part of an ongoing aftershock sequence following the magnitude 5.0 mainshock that occurred 20 days ago 93 km SSW of Unalaska, Alaska. Since the mainshock, the USGS has recorded 33 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.
Earthquake Details
-167.4681°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 3.1 earthquake near Nikolski, Alaska?
The magnitude 3.1 earthquake that struck 95 km E of Nikolski, Alaska on March 18, 2026 at 17:52 UTC had a depth of 7.7 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.
Is this the same earthquake as the M5.0 one earlier?
No. This magnitude 3.1 earthquake is an aftershock of the larger magnitude 5.0 mainshock that occurred earlier 93 km SSW of Unalaska, Alaska. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
What should I do after an earthquake?
If you were in the affected area: check yourself and others for injuries, inspect your home for damage, and be prepared for aftershocks. For detailed guidance, see our earthquake safety guide and emergency planning resources.
Actions
Understanding This Data
Magnitude 3.1 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: us6000shfa). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, March 18, 2026). M3.1 Earthquake 95 km E of Nikolski, Alaska — March 18, 2026. Retrieved May 26, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000shfa/