4.0

M4.0 Earthquake 113 km NE of Atka, AlaskaMay 29, 2026

2026-05-29 10:15:35 UTC (10 hours ago) · approx. 10:15 PM UTC-12 local

MagnitudeM4.0(mb)
Time10:15 UTC10:15 PM UTC-12
Depth230.5 kmintermediate depth
Coordinates52.934°, -173.043°
Felt byNo felt reports
Status✓ Reviewed by USGS

On May 29, 2026 at 10:15 UTC, a magnitude 4.0 intermediate depth earthquake struck 113 km NE of Atka, Alaska, at a depth of 230.5 km and coordinates 52.9336°, -173.0433°.

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 52.93°, -173.04°

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 113 km NE of Atka, Alaska

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

Earthquake Details

Magnitude
4.0 mb
Depth
230.5 km
intermediate depth
Location
52.9336°N
-173.0433°E
Intensity (MMI)
1.0
weak

Technical Information

Event ID
us7000sp8x
Event Type
earthquake
Status
✓ Reviewed
Significance
246
Stations Used
56
Azimuthal Gap
136.0°
Min Station Distance
1.017°
RMS Residual
0.52 sec
Last Updated
2026-05-29 17:58:26 UTC

Common Questions

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

The magnitude 4.0 earthquake that struck 113 km NE of Atka, Alaska on May 29, 2026 at 10:15 UTC had a depth of 230.5 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.

What should I do after an earthquake?

If you were in the affected area: check yourself and others for injuries, inspect your home for damage, and be prepared for aftershocks. For detailed guidance, see our earthquake safety guide and emergency planning resources.

Authoritative source: USGS event page (event ID: us7000sp8x). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, May 29, 2026). M4.0 Earthquake 113 km NE of Atka, AlaskaMay 29, 2026. Retrieved May 29, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000sp8x/