3.9

M3.9 Earthquake 242 km ESE of Attu Station, AlaskaMarch 2, 2026

2026-03-02 19:13:55 UTC (2026-03-02) · approx. 7:13 AM UTC+12 local

MagnitudeM3.9(mb)
Time19:13 UTC7:13 AM UTC+12
Depth10.0 kmshallow crustal
Coordinates51.957°, 176.436°
Felt byNo felt reports
Status✓ Reviewed by USGS

On March 2, 2026 at 19:13 UTC, a magnitude 3.9 shallow crustal earthquake struck 242 km ESE of Attu Station, Alaska, at a depth of 10.0 km and coordinates 51.9571°, 176.4356°.

Physical scale: An earthquake of magnitude 3.9 releases seismic energy equivalent to roughly 11 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 296 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 5.8 mainshock that occurred 7 days ago 235 km ESE of Attu Station, Alaska. Since the mainshock, the USGS has recorded 19 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.

Map showing earthquake epicenter at 51.96°, 176.44°

Earthquake Details

Magnitude
3.9 mb
Depth
10.0 km
shallow crustal
Location
51.9571°N
176.4356°E

Technical Information

Event ID
us6000sg3p
Event Type
earthquake
Status
✓ Reviewed
Significance
234
Stations Used
25
Azimuthal Gap
186.0°
Min Station Distance
1.322°
RMS Residual
0.36 sec
Last Updated
2026-03-14 16:27:58 UTC

Common Questions

How strong was the magnitude 3.9 earthquake near Attu Station, Alaska?

The magnitude 3.9 earthquake that struck 242 km ESE of Attu Station, Alaska on March 2, 2026 at 19:13 UTC had a depth of 10.0 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 3.9 earthquakes can continue for several days and gradually diminish over time.

Is this the same earthquake as the M5.8 one earlier?

No. This magnitude 3.9 earthquake is an aftershock of the larger magnitude 5.8 mainshock that occurred earlier 235 km ESE of Attu Station, 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.

Authoritative source: USGS event page (event ID: us6000sg3p). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, March 2, 2026). M3.9 Earthquake 242 km ESE of Attu Station, AlaskaMarch 2, 2026. Retrieved May 13, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000sg3p/