3.1

M3.1 Earthquake 256 km SSW of Adak, AlaskaMarch 27, 2026

2026-03-27 21:15:00 UTC (2026-03-27) · approx. 9:15 AM UTC-12 local

MagnitudeM3.1(ml)
Time21:15 UTC9:15 AM UTC-12
Depth10.0 kmshallow crustal
Coordinates49.648°, -177.601°
Felt byNo felt reports
Status✓ Reviewed by USGS

On March 27, 2026 at 21:15 UTC, a magnitude 3.1 shallow crustal earthquake struck 256 km SSW of Adak, Alaska, at a depth of 10.0 km and coordinates 49.6475°, -177.6007°.

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.

Map showing earthquake epicenter at 49.65°, -177.60°

Earthquake Details

Magnitude
3.1 ml
Depth
10.0 km
shallow crustal
Location
49.6475°N
-177.6007°E

Technical Information

Event ID
us7000s897
Event Type
earthquake
Status
✓ Reviewed
Significance
148
Stations Used
18
Azimuthal Gap
273.0°
Min Station Distance
2.059°
RMS Residual
0.49 sec
Last Updated
2026-04-18 22:46:49 UTC

Common Questions

How strong was the magnitude 3.1 earthquake near Adak, Alaska?

The magnitude 3.1 earthquake that struck 256 km SSW of Adak, Alaska on March 27, 2026 at 21:15 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 3.1 earthquakes can continue for several days and gradually diminish over time.

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: us7000s897). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, March 27, 2026). M3.1 Earthquake 256 km SSW of Adak, AlaskaMarch 27, 2026. Retrieved May 13, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000s897/