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Analysis of Recent Magnitude 2.7 Earthquake near Iliamna Volcano in Southern Alaska
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Analysis of Recent Magnitude 2.7 Earthquake near Iliamna Volcano in Southern Alaska

“Explore the tectonic intricacies of Southern Alaska following the recent magnitude 2.7 earthquake near Iliamna Volcano. Uncover the seismic dynamics shaped by the interaction of tectonic plates, offering insights crucial for preparedness and risk mitigation in the region.”

The seismic event registering magnitude 2.7, occurring at 00:56:11 AKST on December 5, 2023 (09:56:11 UTC), and located approximately 25 miles south of Iliamna Volcano at coordinates 59.6979°N 152.8526°W, has prompted an exploration into the intricate tectonic dynamics of Southern Alaska.

Southern Alaska stands as a region profoundly affected by various tectonic features, each contributing to the seismic activity witnessed. The seismicity within Southcentral Alaska, renowned for its potent earthquakes, predominantly arises from the interaction between the subducting Pacific Plate and the overriding North American Plate along the megathrust fault. Notably, the historic 1964 M9.2 Great Alaska Earthquake epitomizes the impact generated by this fault, originating beneath Prince William Sound.

Intermediate-depth seismicity, occurring below 20 miles (32 km) in the Wadati-Benioff Zone, delineates the subduction of the Pacific Plate into the mantle beneath the North American Plate. This seismic zone extends across the Aleutian Arc, Alaska Peninsula, and Cook Inlet, exerting its influence beneath the northern foothills of the Alaska Range. Recent seismic events, such as the 2016 M7.1 Iniskin and the 2018 M7.1 Anchorage earthquakes, showcase the substantial ground shaking and structural damage associated with this seismic realm.

Additionally, the region experiences crustal seismicity stemming from multiple sources, including the faults and folds within the Cook Inlet basin, the Castle Mountain Fault, and a broad band of diffuse seismic activity extending from northern Cook Inlet to the Denali Fault. Historical seismic events, notably the April 1933 M6.9 earthquake, underscore the seismic potential of these geological structures, causing considerable damage in Anchorage.

“A seismic event near Iliamna Volcano unravels the complex tectonic tale of Southern Alaska, revealing the region’s seismic intricacies and the ongoing quest for preparedness.”

The Castle Mountain Fault, situated 25 miles (40 km) north of Anchorage, exhibits geological evidence of Holocene offsets and has been associated with the 1984 M5.6 Sutton Earthquake. Furthermore, the diffuse seismicity observed between Cook Inlet and the Denali Fault might indicate a deformation zone between the Bering microplate and the southern Alaska block, characterized by a series of predominantly thrust faults, possibly contributing to significant seismic occurrences like the 1943 M7.0 earthquake.

The recent magnitude 2.7 earthquake near Iliamna Volcano emerges as a part of this intricate seismic fabric, underscoring the continual necessity for comprehensive monitoring and scientific investigation. Understanding these geological complexities is pivotal for developing robust strategies aimed at enhancing preparedness and resilience against seismic events in Southern Alaska. Continued research remains imperative in deciphering the region’s seismic intricacies and mitigating potential risks effectively.


  • Abigail Thomas

    I'm reporter and multimedia producer for WaxMia. Previously I worked as an associate producer at RT News for about 4 years.

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