4.5

M4.5 Earthquake 92 km S of False Pass, AlaskaSeptember 11, 2026

2026-09-11 07:31:45 UTC (6 hours ago) · approx. 8:31 PM UTC-11 local

MagnitudeM4.5(mb)
Time07:31 UTC8:31 PM UTC-11
Depth43.1 kmshallow crustal
Coordinates54.034°, -163.155°
Felt byNo felt reports
Status✓ Reviewed by USGS

On September 11, 2026 at 07:31 UTC, a magnitude 4.5 shallow crustal earthquake struck 92 km S of False Pass, Alaska, at a depth of 43.1 km and coordinates 54.0340°, -163.1555°. This earthquake was detected by 39 seismic stations with good location accuracy and was assigned a USGS significance rating of 312, placing it among routine seismic activity.

Physical scale: An earthquake of magnitude 4.5 releases seismic energy equivalent to roughly 85 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 767 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 54.03°, -163.16°

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 M4.5 earthquake near 92 km S of False Pass, Alaska

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

Earthquake Details

Magnitude
4.5 mb
Depth
43.1 km
shallow crustal
Location
54.0340°N
-163.1555°E
Intensity (MMI)
2.9
weak

Technical Information

Event ID
us7000tgk1
Event Type
earthquake
Status
✓ Reviewed
Significance
312
Stations Used
39
Azimuthal Gap
152.0°
Min Station Distance
0.838°
RMS Residual
0.49 sec
Last Updated
2026-09-11 13:15:36 UTC

Common Questions

How strong was the magnitude 4.5 earthquake near False Pass, Alaska?

The magnitude 4.5 earthquake that struck 92 km S of False Pass, Alaska on September 11, 2026 at 07:31 UTC had a depth of 43.1 km. For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at 54.0340°, -163.1555°, which is 92 km S of False Pass, Alaska. View all earthquakes in Alaska.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.5 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 4.5 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: us7000tgk1). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, September 11, 2026). M4.5 Earthquake 92 km S of False Pass, AlaskaSeptember 11, 2026. Retrieved September 11, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000tgk1/