4.2

M4.2 Earthquake 92 km WNW of False Pass, AlaskaAugust 31, 2026

2026-08-31 23:16:53 UTC (48 min ago) · approx. 12:16 PM UTC-11 local

MagnitudeM4.2(mb)
Time23:16 UTC12:16 PM UTC-11
Depth174.4 kmintermediate depth
Coordinates55.063°, -164.810°
Felt byNo felt reports
Status✓ Reviewed by USGS

On August 31, 2026 at 23:16 UTC, a magnitude 4.2 intermediate depth earthquake struck 92 km WNW of False Pass, Alaska, at a depth of 174.4 km and coordinates 55.0626°, -164.8095°.

Physical scale: An earthquake of magnitude 4.2 releases seismic energy equivalent to roughly 30 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 476 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 55.06°, -164.81°

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 M4.2 earthquake near 92 km WNW of False Pass, Alaska

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

Earthquake Details

Magnitude
4.2 mb
Depth
174.4 km
intermediate depth
Location
55.0626°N
-164.8095°E
Intensity (MMI)
1.0
weak

Technical Information

Event ID
us7000td88
Event Type
earthquake
Status
✓ Reviewed
Significance
271
Stations Used
36
Azimuthal Gap
73.0°
Min Station Distance
0.574°
RMS Residual
0.91 sec
Last Updated
2026-08-31 23:40:33 UTC

Common Questions

How strong was the magnitude 4.2 earthquake near False Pass, Alaska?

The magnitude 4.2 earthquake that struck 92 km WNW of False Pass, Alaska on August 31, 2026 at 23:16 UTC had a depth of 174.4 km. For context, this was a light earthquake commonly felt near the epicenter.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.2 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 4.2 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us7000td88). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, August 31, 2026). M4.2 Earthquake 92 km WNW of False Pass, AlaskaAugust 31, 2026. Retrieved August 31, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000td88/