M4.0 Earthquake 133 km E of Chalkyitsik, Alaska — June 25, 2026
2026-06-25 10:58:10 UTC (3 hours ago) · approx. 1:58 AM UTC-9 local
On June 25, 2026 at 10:58 UTC, a magnitude 4.0 shallow crustal earthquake struck 133 km E of Chalkyitsik, Alaska, at a depth of 11.4 km and coordinates 66.6400°, -140.7134°.
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.
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.
Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS
Population exposure (USGS PAGER)
Estimated population that experienced each level of shaking. Based on the USGS PAGER rapid impact assessment, which combines ShakeMap output with global population grids.
| Shaking intensity (MMI) | Description | Population exposed |
|---|
Earthquake Details
-140.7134°E
Technical Information
Common Questions
How strong was the magnitude 4.0 earthquake near Chalkyitsik, Alaska?
The magnitude 4.0 earthquake that struck 133 km E of Chalkyitsik, Alaska on June 25, 2026 at 10:58 UTC had a depth of 11.4 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 4.0 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.
Actions
Understanding This Data
Magnitude 4.0 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us6000t832). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, June 25, 2026). M4.0 Earthquake 133 km E of Chalkyitsik, Alaska — June 25, 2026. Retrieved June 25, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000t832/