3.5

M3.5 Earthquake 32 km ENE of Pedro Bay, AlaskaSeptember 28, 2025

2025-09-28 19:21:45 UTC (2025-09-28) · approx. 9:21 AM UTC-10 local

MagnitudeM3.5(ml)
Time19:21 UTC9:21 AM UTC-10
Depth130.1 kmintermediate depth
Coordinates59.845°, -153.545°
Felt byNo felt reports
Status✓ Reviewed by USGS

On September 28, 2025 at 19:21 UTC, a magnitude 3.5 intermediate depth earthquake struck 32 km ENE of Pedro Bay, Alaska, at a depth of 130.1 km and coordinates 59.8447°, -153.5449°.

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 59.84°, -153.54°

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 M3.5 earthquake near 32 km ENE of Pedro Bay, Alaska

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

Earthquake Details

Magnitude
3.5 ml
Depth
130.1 km
intermediate depth
Location
59.8447°N
-153.5449°E
Intensity (MMI)
3.1
light

Technical Information

Event ID
ak025cgi2vuu
Event Type
earthquake
Status
✓ Reviewed
Significance
188
RMS Residual
0.58 sec
Last Updated
2025-12-11 21:40:41 UTC

Common Questions

How strong was the magnitude 3.5 earthquake near Pedro Bay, Alaska?

The magnitude 3.5 earthquake that struck 32 km ENE of Pedro Bay, Alaska on September 28, 2025 at 19:21 UTC had a depth of 130.1 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.

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: ak025cgi2vuu). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2025, September 28, 2025). M3.5 Earthquake 32 km ENE of Pedro Bay, AlaskaSeptember 28, 2025. Retrieved May 28, 2026 from https://www.earthquaketracker.org/earthquakes/event/ak025cgi2vuu/