3.3

M3.3 Earthquake 175 km WSW of Nikolski, AlaskaJuly 3, 2025

2025-07-03 19:28:21 UTC (2025-07-03) · approx. 8:28 AM UTC-11 local

MagnitudeM3.3(ml)
Time19:28 UTC8:28 AM UTC-11
Depth35.0 kmshallow crustal
Coordinates52.106°, -171.057°
Felt byNo felt reports
Status✓ Reviewed by USGS

On July 3, 2025 at 19:28 UTC, a magnitude 3.3 shallow crustal earthquake struck 175 km WSW of Nikolski, Alaska, at a depth of 35.0 km and coordinates 52.1056°, -171.0567°.

Physical scale: An earthquake of magnitude 3.3 releases seismic energy equivalent to roughly 1.3 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 114 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 52.11°, -171.06°

Earthquake Details

Magnitude
3.3 ml
Depth
35.0 km
shallow crustal
Location
52.1056°N
-171.0567°E

Technical Information

Event ID
us7000qbxi
Event Type
earthquake
Status
✓ Reviewed
Significance
168
Stations Used
19
Azimuthal Gap
212.0°
Min Station Distance
0.976°
RMS Residual
1.05 sec
Last Updated
2025-09-12 16:23:06 UTC

Common Questions

How strong was the magnitude 3.3 earthquake near Nikolski, Alaska?

The magnitude 3.3 earthquake that struck 175 km WSW of Nikolski, Alaska on July 3, 2025 at 19:28 UTC had a depth of 35.0 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 3.3 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 3.3 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us7000qbxi). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2025, July 3, 2025). M3.3 Earthquake 175 km WSW of Nikolski, AlaskaJuly 3, 2025. Retrieved September 12, 2025 from https://www.earthquaketracker.org/earthquakes/event/us7000qbxi/