3.4

M3.4 Earthquake 38 km WSW of Skwentna, AlaskaJanuary 28, 2023

2023-01-28 19:15:55 UTC (2023-01-28) · approx. 9:15 AM UTC-10 local

MagnitudeM3.4(ml)
Time19:15 UTC9:15 AM UTC-10
Depth118.4 kmintermediate depth
Coordinates61.915°, -152.120°
Felt byNo felt reports
Status✓ Reviewed by USGS

On January 28, 2023 at 19:15 UTC, a magnitude 3.4 intermediate depth earthquake struck 38 km WSW of Skwentna, Alaska, at a depth of 118.4 km and coordinates 61.9151°, -152.1201°.

Physical scale: An earthquake of magnitude 3.4 releases seismic energy equivalent to roughly 1.9 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 134 m — a useful intuition for the size of the slip patch on the fault.

This earthquake is part of an ongoing aftershock sequence following the magnitude 5.6 mainshock that occurred 26 days ago 57 km WNW of Skwentna, Alaska. Since the mainshock, the USGS has recorded 18 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.

Map showing earthquake epicenter at 61.92°, -152.12°

Earthquake Details

Magnitude
3.4 ml
Depth
118.4 km
intermediate depth
Location
61.9151°N
-152.1201°E

Technical Information

Event ID
ak0231amga7c
Event Type
earthquake
Status
✓ Reviewed
Significance
178
RMS Residual
0.70 sec
Last Updated
2023-04-11 18:51:39 UTC

Common Questions

How strong was the magnitude 3.4 earthquake near Skwentna, Alaska?

The magnitude 3.4 earthquake that struck 38 km WSW of Skwentna, Alaska on January 28, 2023 at 19:15 UTC had a depth of 118.4 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 3.4 earthquakes can continue for several days and gradually diminish over time.

Is this the same earthquake as the M5.6 one earlier?

No. This magnitude 3.4 earthquake is an aftershock of the larger magnitude 5.6 mainshock that occurred earlier 57 km WNW of Skwentna, Alaska. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.

Understanding This Data

Magnitude 3.4 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: ak0231amga7c). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2023, January 28, 2023). M3.4 Earthquake 38 km WSW of Skwentna, AlaskaJanuary 28, 2023. Retrieved April 11, 2023 from https://www.earthquaketracker.org/earthquakes/event/ak0231amga7c/