4.1

M4.1 Earthquake near Rat Islands, Aleutian Islands, AlaskaOctober 21, 2022

2022-10-21 20:44:23 UTC (2022-10-21) · approx. 8:44 AM UTC+12 local

MagnitudeM4.1(mb)
Time20:44 UTC8:44 AM UTC+12
Depth109.5 kmintermediate depth
Coordinates51.769°, 178.361°
Felt byNo felt reports
Status✓ Reviewed by USGS

On October 21, 2022 at 20:44 UTC, a magnitude 4.1 intermediate depth earthquake struck near Rat Islands, Aleutian Islands, Alaska, at a depth of 109.5 km and coordinates 51.7687°, 178.3606°.

Physical scale: An earthquake of magnitude 4.1 releases seismic energy equivalent to roughly 21 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 406 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 51.77°, 178.36°

Earthquake Details

Magnitude
4.1 mb
Depth
109.5 km
intermediate depth
Location
51.7687°N
178.3606°E

Technical Information

Event ID
us7000inpl
Event Type
earthquake
Status
✓ Reviewed
Significance
259
Stations Used
57
Azimuthal Gap
128.0°
Min Station Distance
0.203°
RMS Residual
0.63 sec
Last Updated
2024-01-18 17:14:37 UTC

Common Questions

How strong was the magnitude 4.1 earthquake near Rat Islands, Aleutian Islands, Alaska?

The magnitude 4.1 earthquake that struck near Rat Islands, Aleutian Islands, Alaska on October 21, 2022 at 20:44 UTC had a depth of 109.5 km. For context, this was a light earthquake commonly felt near the epicenter.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.1 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 4.1 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us7000inpl). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2022, October 21, 2022). M4.1 Earthquake near Rat Islands, Aleutian Islands, AlaskaOctober 21, 2022. Retrieved January 18, 2024 from https://www.earthquaketracker.org/earthquakes/event/us7000inpl/