3.8

M3.8 Earthquake near Rat Islands, Aleutian Islands, Alaska — May 23, 2021

2021-05-23 21:56:37 UTC (2021-05-23) · approx. 9:56 AM UTC+12 local

MagnitudeM3.8(mb)
Time21:56 UTC≈ 9:56 AM UTC+12
Depth119.1 kmintermediate depth
Coordinates52.145°, 178.163°
Felt byNo felt reports
Status✓ Reviewed by USGS

On May 23, 2021 at 21:56 UTC, a magnitude 3.8 intermediate depth earthquake struck near Rat Islands, Aleutian Islands, Alaska, at a depth of 119.1 km and coordinates 52.1451°, 178.1629°.

Physical scale: An earthquake of magnitude 3.8 releases seismic energy equivalent to roughly 7.6 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 252 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 52.15°, 178.16°

Earthquake Details

Magnitude
3.8 mb
Depth
119.1 km
intermediate depth
Location
52.1451°N
178.1629°E

Technical Information

Event ID
us6000efgk
Event Type
earthquake
Status
✓ Reviewed
Significance
222
Azimuthal Gap
186.0°
Min Station Distance
1.902°
RMS Residual
0.60 sec
Last Updated
2021-07-31 22:09:02 UTC

Common Questions

How strong was the magnitude 3.8 earthquake near Rat Islands, Aleutian Islands, Alaska?

The magnitude 3.8 earthquake that struck near Rat Islands, Aleutian Islands, Alaska on May 23, 2021 at 21:56 UTC had a depth of 119.1 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 3.8 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 3.8 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us6000efgk). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, May 23, 2021). M3.8 Earthquake near Rat Islands, Aleutian Islands, Alaska — May 23, 2021. Retrieved July 31, 2021 from https://www.earthquaketracker.org/earthquakes/event/us6000efgk/