4.2

M4.2 Earthquake 148 km NNE of Ambler, AlaskaDecember 10, 2025

2025-12-10 22:17:11 UTC (2025-12-10) · approx. 12:17 PM UTC-10 local

MagnitudeM4.2(ml)
Time22:17 UTC12:17 PM UTC-10
Depth0.5 kmshallow crustal
Coordinates68.308°, -156.462°
Felt by1DYFI response· max MMI 4.5
Status✓ Reviewed by USGS

On December 10, 2025 at 22:17 UTC, a magnitude 4.2 shallow crustal earthquake struck 148 km NNE of Ambler, Alaska, at a depth of 0.5 km and coordinates 68.3080°, -156.4620°. The earthquake was reported felt by 1 personacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 4.5 (moderate).

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 68.31°, -156.46°

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 148 km NNE of Ambler, Alaska

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

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 1 citizen response to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.

USGS DYFI community-reported intensity map for the M4.2 earthquake near 148 km NNE of Ambler, Alaska

Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report

Earthquake Details

Magnitude
4.2 ml
Depth
0.5 km
shallow crustal
Location
68.3080°N
-156.4620°E
Felt Reports
1
DYFI responses
Intensity (MMI)
4.5
moderate
Community Intensity
2.0
CDI from reports

Technical Information

Event ID
ak2025yhikfe
Event Type
earthquake
Status
✓ Reviewed
Significance
272
Stations Used
111
Azimuthal Gap
86.0°
Min Station Distance
0.900°
RMS Residual
1.10 sec
Last Updated
2026-03-10 22:18:35 UTC

Common Questions

How strong was the magnitude 4.2 earthquake near Ambler, Alaska?

The magnitude 4.2 earthquake that struck 148 km NNE of Ambler, Alaska on December 10, 2025 at 22:17 UTC had a depth of 0.5 km. It was felt by 1 person with maximum shaking intensity of MMI 4.5 (moderate). 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.

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: ak2025yhikfe). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2025, December 10, 2025). M4.2 Earthquake 148 km NNE of Ambler, AlaskaDecember 10, 2025. Retrieved May 24, 2026 from https://www.earthquaketracker.org/earthquakes/event/ak2025yhikfe/