Magnitude 5.3 Earthquake Strikes Southcentral Alaska
Date: May 8, 2025
Time: 22:51:23 AKDT (06:51:23 UTC, May 9, 2025)
Location: 60.3192°N, 150.8542°W; 14 miles E of Kasilof, 15 miles S of Sterling
Depth: 33.3 miles (53 km)
The United States Geological Survey (USGS) reported a magnitude 5.3 earthquake in Southcentral Alaska. The epicenter was located approximately 14 miles east of Kasilof and 15 miles south of Sterling. The quake, with a depth of 33.3 miles, has not yet been reviewed by a seismologist.
Tectonic Background
Southcentral Alaska’s seismic activity is influenced by various tectonic features. The region is primarily shaped by the megathrust fault, which marks the boundary where the Pacific Plate subducts beneath the North American Plate. This fault was responsible for the 1964 Great Alaska Earthquake, the second-largest ever recorded.
Intermediate-depth earthquakes occur in the Wadati-Benioff Zone, extending along the Aleutian Arc and terminating beneath the Alaska Range. Notable events in this category include the 2016 M7.1 Iniskin and 2018 M7.1 Anchorage earthquakes, which caused significant structural damage.
Additionally, crustal seismicity in the Cook Inlet basin, Castle Mountain Fault, and a diffuse seismic zone between Cook Inlet and the Denali Fault contribute to the region’s earthquake risks. The April 1933 M6.9 earthquake and the 1984 M5.6 Sutton Earthquake are key examples of the region’s seismic history.
Source
Photo credit earthquake.alaska.edu
