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Lithospheric Modification in Northeastern Alaska Interpreted From Full-Wave Ambient Noise Tomography

Subduction margins undergo long-term deformation over geologic time that can deform the overriding plate for hundreds of kilometers. Numerical modeling of subduction dynamics and deformation of overriding plates suggest far-field (1000s km) inboard deformation as the result of shallow subduction. Previous studies of the upper plate of northeastern Alaska focus primarily on data from surface deformation using geodetic measurements. However, the 3-D deeper structural modification of the overriding lithosphere is unclear. The Yakutat microplate in Alaska is a shallowly dipping subducting slab characterized by high coupling with the overriding North American Plate. The collision of the Yakutat microplate with the North American continent reactivated a system of right-lateral strike-slip faults across Alaska and Yukon, including the Denali Fault in southern Alaska and the Tintina Fault in eastern Alaska. Here, we use full-wave ambient noise tomography to produce a high-resolution image of northeastern Alaska, covering the eastern Brooks Range, the Porcupine Shear Zone, the Yukon Flats Basin, and the Tintina Fault. We will present the shear-wave velocity structure of the lithosphere and discuss the lithospheric modification and the surface geologic record in northeastern Alaska associated with the shallow subduction of the Pacific plate and the Yakutat microplate along the southern Alaska convergent margin.

Session: Earth’s Structure from the Crust to the Core [Poster Session]

Type: Poster

Room: Exhibit Hall

Date: 5/2/2024

Presentation Time: 08:00 AM (local time)

Presenting Author: Vincent Sassard

Student Presenter: Yes

Additional Authors