4.7

M4.7 Earthquake 143 km SE of Perryville, AlaskaJuly 23, 2024

2024-07-23 08:17:57 UTC (2024-07-23) · approx. 9:17 PM UTC-11 local

MagnitudeM4.7(mwr)
Time08:17 UTC9:17 PM UTC-11
Depth9.8 kmshallow crustal
Coordinates54.996°, -157.540°
Felt byNo felt reports
Status✓ Reviewed by USGS

On July 23, 2024 at 08:17 UTC, a magnitude 4.7 shallow crustal earthquake struck 143 km SE of Perryville, Alaska, at a depth of 9.8 km and coordinates 54.9959°, -157.5398°.

Physical scale: An earthquake of magnitude 4.7 releases seismic energy equivalent to roughly 169 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.1 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 55.00°, -157.54°

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 M4.7 earthquake near 143 km SE of Perryville, Alaska

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

Earthquake Details

Magnitude
4.7 mwr
Depth
9.8 km
shallow crustal
Location
54.9959°N
-157.5398°E
Intensity (MMI)
2.3
weak

Technical Information

Event ID
ak0249f61dl8
Event Type
earthquake
Status
✓ Reviewed
Significance
340
RMS Residual
0.67 sec
Last Updated
2024-10-08 21:49:10 UTC

Common Questions

How strong was the magnitude 4.7 earthquake near Perryville, Alaska?

The magnitude 4.7 earthquake that struck 143 km SE of Perryville, Alaska on July 23, 2024 at 08:17 UTC had a depth of 9.8 km. For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at 54.9959°, -157.5398°, which is 143 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 4.7 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 4.7 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: ak0249f61dl8). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2024, July 23, 2024). M4.7 Earthquake 143 km SE of Perryville, AlaskaJuly 23, 2024. Retrieved October 8, 2024 from https://www.earthquaketracker.org/earthquakes/event/ak0249f61dl8/