3.4

M3.4 Earthquake 73 km SW of Kaktovik, AlaskaSeptember 27, 2021

2021-09-27 22:30:27 UTC (2021-09-27) · approx. 12:30 PM UTC-10 local

MagnitudeM3.4(ml)
Time22:30 UTC12:30 PM UTC-10
Depth20.9 kmshallow crustal
Coordinates69.588°, -144.717°
Felt byNo felt reports
Status✓ Reviewed by USGS

On September 27, 2021 at 22:30 UTC, a magnitude 3.4 shallow crustal earthquake struck 73 km SW of Kaktovik, Alaska, at a depth of 20.9 km and coordinates 69.5882°, -144.7167°.

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.

Map showing earthquake epicenter at 69.59°, -144.72°

Earthquake Details

Magnitude
3.4 ml
Depth
20.9 km
shallow crustal
Location
69.5882°N
-144.7167°E

Technical Information

Event ID
ak021cewdqar
Event Type
earthquake
Status
✓ Reviewed
Significance
178
RMS Residual
0.51 sec
Last Updated
2021-12-04 14:30:00 UTC

Common Questions

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

The magnitude 3.4 earthquake that struck 73 km SW of Kaktovik, Alaska on September 27, 2021 at 22:30 UTC had a depth of 20.9 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 3.4 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 3.4 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: ak021cewdqar). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, September 27, 2021). M3.4 Earthquake 73 km SW of Kaktovik, AlaskaSeptember 27, 2021. Retrieved December 4, 2021 from https://www.earthquaketracker.org/earthquakes/event/ak021cewdqar/