5.3

M5.3 Earthquake 151 km WSW of Adak, AlaskaSeptember 11, 2026

2026-09-11 10:47:12 UTC (1 hour ago) · approx. 10:47 PM UTC-12 local

Maximum shaking intensity MMI 5.3 (strong).

MagnitudeM5.3(mb)
Time10:47 UTC10:47 PM UTC-12
Depth40.9 kmshallow crustal
Coordinates51.213°, -178.543°
Felt byNo felt reports
Status✓ Reviewed by USGS· Tsunami evaluation
Tsunami Warning Issued

On September 11, 2026 at 10:47 UTC, a magnitude 5.3 shallow crustal earthquake struck 151 km WSW of Adak, Alaska, at a depth of 40.9 km and coordinates 51.2130°, -178.5429°. This earthquake was detected by 107 seismic stations with good location accuracy and was assigned a USGS significance rating of 432, placing it among routine seismic activity.

Physical scale: An earthquake of magnitude 5.3 releases seismic energy equivalent to roughly 1 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 2.7 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 51.21°, -178.54°

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 M5.3 earthquake near 151 km WSW of Adak, Alaska

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

Earthquake Details

Magnitude
5.3 mb
Depth
40.9 km
shallow crustal
Location
51.2130°N
-178.5429°E
Intensity (MMI)
5.3
strong

Technical Information

Event ID
us7000tgky
Event Type
earthquake
Status
✓ Reviewed
Significance
432
Stations Used
107
Azimuthal Gap
127.0°
Min Station Distance
0.381°
RMS Residual
1.11 sec
Last Updated
2026-09-11 11:47:27 UTC

Common Questions

How strong was the magnitude 5.3 earthquake near Adak, Alaska?

The magnitude 5.3 earthquake that struck 151 km WSW of Adak, Alaska on September 11, 2026 at 10:47 UTC had a depth of 40.9 km. For context, this was a moderate earthquake that could be widely felt.

Where did the earthquake occur?

The earthquake epicenter was located at 51.2130°, -178.5429°, which is 151 km WSW of Adak, Alaska. View all earthquakes in Alaska.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.3 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 5.3 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: us7000tgky). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, September 11, 2026). M5.3 Earthquake 151 km WSW of Adak, AlaskaSeptember 11, 2026. Retrieved September 11, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000tgky/