3.1

M3.1 Earthquake 263 km ESE of Chiniak, AlaskaJuly 7, 2025

2025-07-07 19:59:54 UTC (2025-07-07) · approx. 9:59 AM UTC-10 local

MagnitudeM3.1(ml)
Time19:59 UTC9:59 AM UTC-10
Depth10.0 kmshallow crustal
Coordinates56.508°, -148.433°
Felt byNo felt reports
Status✓ Reviewed by USGS

On July 7, 2025 at 19:59 UTC, a magnitude 3.1 shallow crustal earthquake struck 263 km ESE of Chiniak, Alaska, at a depth of 10.0 km and coordinates 56.5079°, -148.4334°.

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 56.51°, -148.43°

Earthquake Details

Magnitude
3.1 ml
Depth
10.0 km
shallow crustal
Location
56.5079°N
-148.4334°E

Technical Information

Event ID
us7000qb88
Event Type
earthquake
Status
✓ Reviewed
Significance
148
Stations Used
56
Azimuthal Gap
173.0°
Min Station Distance
2.598°
RMS Residual
0.63 sec
Last Updated
2025-09-12 16:23:11 UTC

Common Questions

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

The magnitude 3.1 earthquake that struck 263 km ESE of Chiniak, Alaska on July 7, 2025 at 19:59 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 3.1 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: us7000qb88). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2025, July 7, 2025). M3.1 Earthquake 263 km ESE of Chiniak, AlaskaJuly 7, 2025. Retrieved September 12, 2025 from https://www.earthquaketracker.org/earthquakes/event/us7000qb88/