4.9

M4.9 Earthquake near Rat Islands, Aleutian Islands, AlaskaFebruary 21, 2025

2025-02-21 07:07:09 UTC (2025-02-21) · approx. 7:07 PM UTC+12 local

Felt by 1 person across nearby locations.

MagnitudeM4.9(mb)
Time07:07 UTC7:07 PM UTC+12
Depth52.3 kmshallow crustal
Coordinates51.526°, 178.138°
Felt by1DYFI response· max MMI 3.7
Status✓ Reviewed by USGS

On February 21, 2025 at 07:07 UTC, a magnitude 4.9 shallow crustal earthquake struck near Rat Islands, Aleutian Islands, Alaska, at a depth of 52.3 km and coordinates 51.5262°, 178.1377°. The earthquake was reported felt by 1 personacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 3.7 (light). This earthquake was detected by 246 seismic stations with good location accuracy and was assigned a USGS significance rating of 369, placing it among routine seismic activity.

Physical scale: An earthquake of magnitude 4.9 releases seismic energy equivalent to roughly 338 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.4 km — a useful intuition for the size of the slip patch on the fault.

The epicenter is located in Alaska, a region characterized by Pacific Plate subduction beneath the North American Plate, producing frequent megathrust and crustal earthquakes along the Aleutian arc. The nearest mapped fault system is the Aleutian megathrust. View all earthquakes in Alaska.

Learn more: Magnitude scale · Aftershock sequences

Map showing earthquake epicenter at 51.53°, 178.14°

ShakeMap — predicted shaking intensity

Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.

USGS ShakeMap intensity contours for the M4.9 earthquake near Rat Islands, Aleutian Islands, Alaska

Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 1 citizen response to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.

USGS DYFI community-reported intensity map for the M4.9 earthquake near Rat Islands, Aleutian Islands, Alaska

Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report

Earthquake Details

Magnitude
4.9 mb
Depth
52.3 km
shallow crustal
Location
51.5262°N
178.1377°E
Felt Reports
1
DYFI responses
Intensity (MMI)
3.7
light
Community Intensity
0.0
CDI from reports

Technical Information

Event ID
us7000pf61
Event Type
earthquake
Status
✓ Reviewed
Significance
369
Stations Used
246
Azimuthal Gap
109.0°
Min Station Distance
0.482°
RMS Residual
0.95 sec
Last Updated
2025-05-06 21:39:17 UTC

Common Questions

How strong was the magnitude 4.9 earthquake near Rat Islands, Aleutian Islands, Alaska?

The magnitude 4.9 earthquake that struck near Rat Islands, Aleutian Islands, Alaska on February 21, 2025 at 07:07 UTC had a depth of 52.3 km. It was felt by 1 person with maximum shaking intensity of MMI 3.7 (light). For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at 51.5262°, 178.1377°, which is near Rat Islands, Aleutian Islands, Alaska. View all earthquakes in Alaska.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.9 earthquakes can continue for several days and gradually diminish over time.

Has Alaska had earthquakes this big before?

The largest recorded earthquake in Alaska was the M9.2 Great Alaska earthquake of March 27, 1964. Today's magnitude 4.9 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: us7000pf61). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2025, February 21, 2025). M4.9 Earthquake near Rat Islands, Aleutian Islands, AlaskaFebruary 21, 2025. Retrieved May 6, 2025 from https://www.earthquaketracker.org/earthquakes/event/us7000pf61/