4.0

M4.0 Earthquake 203 km SE of Unalaska, Alaska — November 7, 2026

2026-11-07 19:45:08 UTC (11 hours ago) · approx. 8:45 AM UTC-11 local

MagnitudeM4.0(ml)
Time19:45 UTC≈ 8:45 AM UTC-11
Depth27.9 kmshallow crustal
Coordinates52.377°, -164.782°
Felt byNo felt reports
Status✓ Reviewed by USGS

On November 7, 2026 at 19:45 UTC, a magnitude 4.0 shallow crustal earthquake struck 203 km SE of Unalaska, Alaska, at a depth of 27.9 km and coordinates 52.3770°, -164.7820°.

Physical scale: An earthquake of magnitude 4.0 releases seismic energy equivalent to roughly 15 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 347 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 52.38°, -164.78°

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 M4.0 earthquake near 203 km SE of Unalaska, Alaska

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

Earthquake Details

Magnitude
4.0 ml
Depth
27.9 km
shallow crustal
Location
52.3770°N
-164.7820°E
Intensity (MMI)
1.0
weak

Technical Information

Event ID
aka2026wcchuf
Event Type
earthquake
Status
✓ Reviewed
Significance
246
Stations Used
99
Azimuthal Gap
216.0°
Min Station Distance
1.800°
RMS Residual
0.80 sec
Last Updated
2026-11-08 06:03:10 UTC

Common Questions

How strong was the magnitude 4.0 earthquake near Unalaska, Alaska?

The magnitude 4.0 earthquake that struck 203 km SE of Unalaska, Alaska on November 7, 2026 at 19:45 UTC had a depth of 27.9 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 4.0 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 4.0 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: aka2026wcchuf). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, November 7, 2026). M4.0 Earthquake 203 km SE of Unalaska, Alaska — November 7, 2026. Retrieved November 8, 2026 from https://www.earthquaketracker.org/earthquakes/event/aka2026wcchuf/