3.8

M3.8 Earthquake 105 km ESE of Atka, AlaskaAugust 28, 2025

2025-08-28 17:59:58 UTC (2025-08-28) · approx. 5:59 AM UTC-12 local

MagnitudeM3.8(mb)
Time17:59 UTC5:59 AM UTC-12
Depth65.4 kmshallow crustal
Coordinates51.902°, -172.737°
Felt byNo felt reports
Status✓ Reviewed by USGS

On August 28, 2025 at 17:59 UTC, a magnitude 3.8 shallow crustal earthquake struck 105 km ESE of Atka, Alaska, at a depth of 65.4 km and coordinates 51.9017°, -172.7372°.

Physical scale: An earthquake of magnitude 3.8 releases seismic energy equivalent to roughly 7.6 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 252 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 51.90°, -172.74°

ShakeMap — predicted shaking intensity

Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.

USGS ShakeMap intensity contours for the M3.8 earthquake near 105 km ESE of Atka, Alaska

Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS

Earthquake Details

Magnitude
3.8 mb
Depth
65.4 km
shallow crustal
Location
51.9017°N
-172.7372°E
Intensity (MMI)
3.2
light

Technical Information

Event ID
us7000qrqn
Event Type
earthquake
Status
✓ Reviewed
Significance
222
Stations Used
30
Azimuthal Gap
190.0°
Min Station Distance
0.919°
RMS Residual
0.57 sec
Last Updated
2025-11-19 21:59:42 UTC

Common Questions

How strong was the magnitude 3.8 earthquake near Atka, Alaska?

The magnitude 3.8 earthquake that struck 105 km ESE of Atka, Alaska on August 28, 2025 at 17:59 UTC had a depth of 65.4 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 3.8 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 3.8 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us7000qrqn). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2025, August 28, 2025). M3.8 Earthquake 105 km ESE of Atka, AlaskaAugust 28, 2025. Retrieved November 19, 2025 from https://www.earthquaketracker.org/earthquakes/event/us7000qrqn/