3.1

M3.1 Earthquake 61 km NE of Adak, AlaskaAugust 11, 2025

2025-08-11 19:47:33 UTC (2025-08-11) · approx. 7:47 AM UTC-12 local

MagnitudeM3.1(ml)
Time19:47 UTC7:47 AM UTC-12
Depth202.5 kmintermediate depth
Coordinates52.282°, -176.030°
Felt byNo felt reports
Status✓ Reviewed by USGS

On August 11, 2025 at 19:47 UTC, a magnitude 3.1 intermediate depth earthquake struck 61 km NE of Adak, Alaska, at a depth of 202.5 km and coordinates 52.2825°, -176.0301°.

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 52.28°, -176.03°

Earthquake Details

Magnitude
3.1 ml
Depth
202.5 km
intermediate depth
Location
52.2825°N
-176.0301°E

Technical Information

Event ID
us6000r1th
Event Type
earthquake
Status
✓ Reviewed
Significance
148
Stations Used
26
Azimuthal Gap
135.0°
Min Station Distance
0.189°
RMS Residual
0.15 sec
Last Updated
2025-10-25 13:40:41 UTC

Common Questions

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

The magnitude 3.1 earthquake that struck 61 km NE of Adak, Alaska on August 11, 2025 at 19:47 UTC had a depth of 202.5 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.

Understanding This Data

Magnitude 3.1 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us6000r1th). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2025, August 11, 2025). M3.1 Earthquake 61 km NE of Adak, AlaskaAugust 11, 2025. Retrieved October 25, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000r1th/