4.8

M4.8 Earthquake 188 km SE of Perryville, AlaskaAugust 29, 2026

2026-08-29 15:16:54 UTC (25 min ago) · approx. 5:16 AM UTC-10 local

MagnitudeM4.8(ml)
Time15:16 UTC5:16 AM UTC-10
Depth5.7 kmshallow crustal
Coordinates54.788°, -156.924°
Felt byNo felt reports
StatusAutomatic (preliminary)

On August 29, 2026 at 15:16 UTC, a magnitude 4.8 shallow crustal earthquake struck 188 km SE of Perryville, Alaska, at a depth of 5.7 km and coordinates 54.7880°, -156.9240°. This earthquake was detected by 280 seismic stations with good location accuracy and was assigned a USGS significance rating of 354, placing it among routine seismic activity.

Physical scale: An earthquake of magnitude 4.8 releases seismic energy equivalent to roughly 239 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.2 km — 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 54.79°, -156.92°

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 M4.8 earthquake near 188 km SE of Perryville, Alaska

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

Earthquake Details

Magnitude
4.8 ml
Depth
5.7 km
shallow crustal
Location
54.7880°N
-156.9240°E
Intensity (MMI)
2.5
weak

Technical Information

Event ID
aka2026rcluqc
Event Type
earthquake
Status
Automatic
Significance
354
Stations Used
280
Azimuthal Gap
169.0°
Min Station Distance
1.800°
RMS Residual
1.10 sec
Last Updated
2026-08-29 15:39:20 UTC

Common Questions

How strong was the magnitude 4.8 earthquake near Perryville, Alaska?

The magnitude 4.8 earthquake that struck 188 km SE of Perryville, Alaska on August 29, 2026 at 15:16 UTC had a depth of 5.7 km. For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at 54.7880°, -156.9240°, which is 188 km SE of Perryville, Alaska. View all earthquakes in Alaska.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.8 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 4.8 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: aka2026rcluqc). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, August 29, 2026). M4.8 Earthquake 188 km SE of Perryville, AlaskaAugust 29, 2026. Retrieved August 29, 2026 from https://www.earthquaketracker.org/earthquakes/event/aka2026rcluqc/