3.2

M3.2 Earthquake 82 km SSE of Adak, AlaskaApril 16, 2025

2025-04-16 19:31:39 UTC (2025-04-16) · approx. 7:31 AM UTC-12 local

MagnitudeM3.2(ml)
Time19:31 UTC7:31 AM UTC-12
Depth18.2 kmshallow crustal
Coordinates51.157°, -176.304°
Felt byNo felt reports
Status✓ Reviewed by USGS

On April 16, 2025 at 19:31 UTC, a magnitude 3.2 shallow crustal earthquake struck 82 km SSE of Adak, Alaska, at a depth of 18.2 km and coordinates 51.1571°, -176.3044°.

Physical scale: An earthquake of magnitude 3.2 releases seismic energy equivalent to roughly 951 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 97 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 4 days ago 94 km SSE of Adak, Alaska. Since the mainshock, the USGS has recorded 4 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 51.16°, -176.30°

Earthquake Details

Magnitude
3.2 ml
Depth
18.2 km
shallow crustal
Location
51.1571°N
-176.3044°E

Technical Information

Event ID
us7000pw9a
Event Type
earthquake
Status
✓ Reviewed
Significance
158
Stations Used
21
Azimuthal Gap
219.0°
Min Station Distance
0.709°
RMS Residual
0.30 sec
Last Updated
2025-06-27 00:34:57 UTC

Common Questions

How strong was the magnitude 3.2 earthquake near Adak, Alaska?

The magnitude 3.2 earthquake that struck 82 km SSE of Adak, Alaska on April 16, 2025 at 19:31 UTC had a depth of 18.2 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 3.2 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 3.2 earthquake is an aftershock of the larger magnitude 5.0 mainshock that occurred earlier 94 km SSE of Adak, Alaska. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.

Understanding This Data

Magnitude 3.2 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us7000pw9a). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2025, April 16, 2025). M3.2 Earthquake 82 km SSE of Adak, AlaskaApril 16, 2025. Retrieved June 27, 2025 from https://www.earthquaketracker.org/earthquakes/event/us7000pw9a/