M4.6 Earthquake 80 km SSE of False Pass, Alaska — May 3, 2026

On May 3, 2026 at 19:20 UTC, a magnitude 4.6 shallow crustal earthquake struck 80 km SSE of False Pass, Alaska, at a depth of 42.7 km and coordinates 54.1902°, -162.9301°. The earthquake was reported felt by 1 personacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 3.8 (light). This earthquake was detected by 31 seismic stations with moderate 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.

This earthquake is part of an ongoing aftershock sequence following the magnitude 5.1 mainshock that occurred 20 days ago 94 km SE of False Pass, Alaska. Since the mainshock, the USGS has recorded 9 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.

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