3.3

M3.3 Earthquake 180 km W of Nikolski, Alaska — October 20, 2026

2026-10-20 23:35:40 UTC (18 hours ago) · approx. 12:35 PM UTC-11 local

MagnitudeM3.3(ml)
Time23:35 UTC≈ 12:35 PM UTC-11
Depth16.8 kmshallow crustal
Coordinates53.187°, -171.520°
Felt byNo felt reports
Status✓ Reviewed by USGS

On October 20, 2026 at 23:35 UTC, a magnitude 3.3 shallow crustal earthquake struck 180 km W of Nikolski, Alaska, at a depth of 16.8 km and coordinates 53.1870°, -171.5200°.

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 53.19°, -171.52°

Earthquake Details

Magnitude
3.3 ml
Depth
16.8 km
shallow crustal
Location
53.1870°N
-171.5200°E

Technical Information

Event ID
aka2026uvdppt
Event Type
earthquake
Status
✓ Reviewed
Significance
168
Stations Used
49
Azimuthal Gap
162.0°
Min Station Distance
1.000°
RMS Residual
0.80 sec
Last Updated
2026-10-21 16:20:14 UTC

Common Questions

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

The magnitude 3.3 earthquake that struck 180 km W of Nikolski, Alaska on October 20, 2026 at 23:35 UTC had a depth of 16.8 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: aka2026uvdppt). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, October 20, 2026). M3.3 Earthquake 180 km W of Nikolski, Alaska — October 20, 2026. Retrieved October 21, 2026 from https://www.earthquaketracker.org/earthquakes/event/aka2026uvdppt/