4.2

M4.2 Earthquake 24 km SSW of Chiniak, AlaskaApril 29, 2026

2026-04-29 02:36:25 UTC (55 min ago) · approx. 4:36 PM UTC-10 local

Felt by 44 people across nearby locations.

MagnitudeM4.2(ml)
Time02:36 UTC4:36 PM UTC-10
Depth47.5 kmshallow crustal
Coordinates57.409°, -152.432°
Felt by44DYFI responses· max MMI 3.7
Status✓ Reviewed by USGS

On April 29, 2026 at 02:36 UTC, a magnitude 4.2 shallow crustal earthquake struck 24 km SSW of Chiniak, Alaska, at a depth of 47.5 km and coordinates 57.4090°, -152.4320°. The earthquake was reported felt by 44 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 3.7 (light). This earthquake was detected by 211 seismic stations with good location accuracy and was assigned a USGS significance rating of 289, placing it among routine seismic activity.

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.

The epicenter is located in Alaska, a region characterized by Pacific Plate subduction beneath the North American Plate, producing frequent megathrust and crustal earthquakes along the Aleutian arc. The nearest mapped fault system is the Aleutian megathrust. View all earthquakes in Alaska.

Learn more: Magnitude scale · Aftershock sequences

Map showing earthquake epicenter at 57.41°, -152.43°

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 24 km SSW of Chiniak, Alaska

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

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 44 citizen responses 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 24 km SSW of Chiniak, Alaska

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

Earthquake Details

Magnitude
4.2 ml
Depth
47.5 km
shallow crustal
Location
57.4090°N
-152.4320°E
Felt Reports
44
DYFI responses
Intensity (MMI)
3.7
light
Community Intensity
4.1
CDI from reports

Technical Information

Event ID
aka2026iiuvdi
Event Type
earthquake
Status
✓ Reviewed
Significance
289
Stations Used
211
Azimuthal Gap
163.0°
Min Station Distance
0.400°
RMS Residual
0.70 sec
Last Updated
2026-04-29 03:21:56 UTC

Common Questions

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

The magnitude 4.2 earthquake that struck 24 km SSW of Chiniak, Alaska on April 29, 2026 at 02:36 UTC had a depth of 47.5 km. It was felt by 44 people with maximum shaking intensity of MMI 3.7 (light). For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at 57.4090°, -152.4320°, which is 24 km SSW of Chiniak, Alaska. View all earthquakes in Alaska.

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.

Has Alaska had earthquakes this big before?

The largest recorded earthquake in Alaska was the M9.2 Great Alaska earthquake of March 27, 1964. Today's magnitude 4.2 event is significantly smaller than that historical record.

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: aka2026iiuvdi). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, April 29, 2026). M4.2 Earthquake 24 km SSW of Chiniak, AlaskaApril 29, 2026. Retrieved April 29, 2026 from https://www.earthquaketracker.org/earthquakes/event/aka2026iiuvdi/