4.6

M4.6 Earthquake 173 km WNW of Adak, AlaskaSeptember 16, 2024

2024-09-16 18:13:02 UTC (2024-09-16) · approx. 6:13 AM UTC-12 local

MagnitudeM4.6(mb)
Time18:13 UTC6:13 AM UTC-12
Depth249.1 kmintermediate depth
Coordinates52.512°, -178.949°
Felt byNo felt reports
Status✓ Reviewed by USGS

On September 16, 2024 at 18:13 UTC, a magnitude 4.6 intermediate depth earthquake struck 173 km WNW of Adak, Alaska, at a depth of 249.1 km and coordinates 52.5116°, -178.9489°. This earthquake was detected by 65 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 326, placing it among routine seismic activity.

Physical scale: An earthquake of magnitude 4.6 releases seismic energy equivalent to roughly 120 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 899 m — 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 52.51°, -178.95°

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 M4.6 earthquake near 173 km WNW of Adak, Alaska

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

Earthquake Details

Magnitude
4.6 mb
Depth
249.1 km
intermediate depth
Location
52.5116°N
-178.9489°E
Intensity (MMI)
1.8
weak

Technical Information

Event ID
us7000neam
Event Type
earthquake
Status
✓ Reviewed
Significance
326
Stations Used
65
Azimuthal Gap
47.0°
Min Station Distance
0.699°
RMS Residual
0.71 sec
Last Updated
2024-11-23 23:27:18 UTC

Common Questions

How strong was the magnitude 4.6 earthquake near Adak, Alaska?

The magnitude 4.6 earthquake that struck 173 km WNW of Adak, Alaska on September 16, 2024 at 18:13 UTC had a depth of 249.1 km. For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at 52.5116°, -178.9489°, which is 173 km WNW of Adak, Alaska. View all earthquakes in Alaska.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.6 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 4.6 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: us7000neam). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2024, September 16, 2024). M4.6 Earthquake 173 km WNW of Adak, AlaskaSeptember 16, 2024. Retrieved November 23, 2024 from https://www.earthquaketracker.org/earthquakes/event/us7000neam/