5.0

M5.0 Earthquake 104 km SSW of Adak, AlaskaFebruary 29, 2024

2024-02-29 09:22:19 UTC (2024-02-29) · approx. 9:22 PM UTC-12 local

Maximum shaking intensity MMI 4.3 (moderate).

MagnitudeM5.0(mww)
Time09:22 UTC9:22 PM UTC-12
Depth26.9 kmshallow crustal
Coordinates51.042°, -177.321°
Felt byNo felt reports
Status✓ Reviewed by USGS

On February 29, 2024 at 09:22 UTC, a magnitude 5.0 shallow crustal earthquake struck 104 km SSW of Adak, Alaska, at a depth of 26.9 km and coordinates 51.0421°, -177.3209°. This earthquake was detected by 200 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 385, placing it among routine seismic activity.

Physical scale: An earthquake of magnitude 5.0 releases seismic energy equivalent to roughly 477 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.7 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 51.04°, -177.32°

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 M5.0 earthquake near 104 km SSW of Adak, Alaska

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

Earthquake Details

Magnitude
5.0 mww
Depth
26.9 km
shallow crustal
Location
51.0421°N
-177.3209°E
Intensity (MMI)
4.3
moderate

Technical Information

Event ID
us6000mfsl
Event Type
earthquake
Status
✓ Reviewed
Significance
385
Stations Used
200
Azimuthal Gap
75.0°
Min Station Distance
0.722°
RMS Residual
0.83 sec
Last Updated
2024-12-12 09:32:33 UTC

Common Questions

How strong was the magnitude 5.0 earthquake near Adak, Alaska?

The magnitude 5.0 earthquake that struck 104 km SSW of Adak, Alaska on February 29, 2024 at 09:22 UTC had a depth of 26.9 km. For context, this was a moderate earthquake that could be widely felt.

Where did the earthquake occur?

The earthquake epicenter was located at 51.0421°, -177.3209°, which is 104 km SSW of Adak, Alaska. View all earthquakes in Alaska.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.0 earthquakes can continue for days to weeks 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 5.0 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: us6000mfsl). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2024, February 29, 2024). M5.0 Earthquake 104 km SSW of Adak, AlaskaFebruary 29, 2024. Retrieved December 12, 2024 from https://www.earthquaketracker.org/earthquakes/event/us6000mfsl/