3.3

M3.3 Earthquake 106 km SSW of Nikolski, AlaskaOctober 20, 2023

2023-10-20 19:13:53 UTC (2023-10-20) · approx. 8:13 AM UTC-11 local

MagnitudeM3.3(ml)
Time19:13 UTC8:13 AM UTC-11
Depth32.9 kmshallow crustal
Coordinates52.058°, -169.488°
Felt byNo felt reports
Status✓ Reviewed by USGS

On October 20, 2023 at 19:13 UTC, a magnitude 3.3 shallow crustal earthquake struck 106 km SSW of Nikolski, Alaska, at a depth of 32.9 km and coordinates 52.0580°, -169.4877°.

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 52.06°, -169.49°

Earthquake Details

Magnitude
3.3 ml
Depth
32.9 km
shallow crustal
Location
52.0580°N
-169.4877°E

Technical Information

Event ID
us7000l8s9
Event Type
earthquake
Status
✓ Reviewed
Significance
168
Stations Used
15
Azimuthal Gap
228.0°
Min Station Distance
0.744°
RMS Residual
0.34 sec
Last Updated
2023-12-26 21:25:07 UTC

Common Questions

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

The magnitude 3.3 earthquake that struck 106 km SSW of Nikolski, Alaska on October 20, 2023 at 19:13 UTC had a depth of 32.9 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: us7000l8s9). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2023, October 20, 2023). M3.3 Earthquake 106 km SSW of Nikolski, AlaskaOctober 20, 2023. Retrieved December 26, 2023 from https://www.earthquaketracker.org/earthquakes/event/us7000l8s9/