3.5

M3.5 Earthquake 206 km SSE of Atka, AlaskaJuly 12, 2025

2025-07-12 16:29:30 UTC (2025-07-12) · approx. 4:29 AM UTC-12 local

MagnitudeM3.5(ml)
Time16:29 UTC4:29 AM UTC-12
Depth10.0 kmshallow crustal
Coordinates50.486°, -173.060°
Felt byNo felt reports
Status✓ Reviewed by USGS

On July 12, 2025 at 16:29 UTC, a magnitude 3.5 shallow crustal earthquake struck 206 km SSE of Atka, Alaska, at a depth of 10.0 km and coordinates 50.4858°, -173.0601°.

Physical scale: An earthquake of magnitude 3.5 releases seismic energy equivalent to roughly 2.7 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 157 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 50.49°, -173.06°

Earthquake Details

Magnitude
3.5 ml
Depth
10.0 km
shallow crustal
Location
50.4858°N
-173.0601°E

Technical Information

Event ID
us7000qcac
Event Type
earthquake
Status
✓ Reviewed
Significance
188
Stations Used
30
Azimuthal Gap
226.0°
Min Station Distance
1.860°
RMS Residual
0.85 sec
Last Updated
2025-11-28 21:01:23 UTC

Common Questions

How strong was the magnitude 3.5 earthquake near Atka, Alaska?

The magnitude 3.5 earthquake that struck 206 km SSE of Atka, Alaska on July 12, 2025 at 16:29 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 3.5 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 3.5 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us7000qcac). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2025, July 12, 2025). M3.5 Earthquake 206 km SSE of Atka, AlaskaJuly 12, 2025. Retrieved November 28, 2025 from https://www.earthquaketracker.org/earthquakes/event/us7000qcac/