3.3

M3.3 Earthquake 83 km SE of Akutan, AlaskaOctober 25, 2021

2021-10-25 21:40:30 UTC (2021-10-25) · approx. 10:40 AM UTC-11 local

MagnitudeM3.3(ml)
Time21:40 UTC10:40 AM UTC-11
Depth27.4 kmshallow crustal
Coordinates53.524°, -165.040°
Felt byNo felt reports
Status✓ Reviewed by USGS

On October 25, 2021 at 21:40 UTC, a magnitude 3.3 shallow crustal earthquake struck 83 km SE of Akutan, Alaska, at a depth of 27.4 km and coordinates 53.5237°, -165.0401°.

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 53.52°, -165.04°

Earthquake Details

Magnitude
3.3 ml
Depth
27.4 km
shallow crustal
Location
53.5237°N
-165.0401°E

Technical Information

Event ID
us6000ga5f
Event Type
earthquake
Status
✓ Reviewed
Significance
168
Azimuthal Gap
220.0°
Min Station Distance
0.750°
RMS Residual
0.56 sec
Last Updated
2022-01-08 17:43:02 UTC

Common Questions

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

The magnitude 3.3 earthquake that struck 83 km SE of Akutan, Alaska on October 25, 2021 at 21:40 UTC had a depth of 27.4 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 3.3 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: us6000ga5f). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, October 25, 2021). M3.3 Earthquake 83 km SE of Akutan, AlaskaOctober 25, 2021. Retrieved January 8, 2022 from https://www.earthquaketracker.org/earthquakes/event/us6000ga5f/