The North American plate in Alaska is an amalgamation of many tectonic terranes (e.g., Colpron et al., 2007) (Figure 1a). The present terranes result from multiple long-term episodes of accretion, accumulation, and deformation due to the dynamic and complex plate boundary interactions of the Pacific, Siberian, and North American Plates (e.g., Shephard et al., 2013). Northern Alaska is a passive margin and was accreted in the late Jurassic (e.g., Moore & Box, 2016;Till, 2016). The Alaskan Interior experienced complex collisional and extensional deformation in the Permian and Cretaceous periods (e.g., Johnston, 2001;Plafker & Berg, 1994). In southern Alaska, accreted terranes docked in the late Mesozoic to Cenozoic, and strike-slip zones developed due to the subduction of the Pacific Plate and Yakutat microplate (e.g., Shephard et al., 2013). Offshore southern Alaska, the Alaska-Aleutian subduction zone is one of the most tectonically and seismically active convergent margins in the world. Historically, a series of great earthquakes have occurred along the megathrust boundary (Figure 1a).With the recent deployment of the USArray Transportable Array (TA) in continental Alaska (Busby & Aderhold, 2020) and the Alaska Amphibious Community Seismic Experiment (AACSE) in the Alaska Peninsula and offshore (Barcheck et al., 2020), as well as other regional networks, new seismic data have become available to investigate the tectonic architecture and history of deformation of Alaska and the subduction zone both onshore and offshore (Figure 1b). Previous seismic studies in Alaska have focused both on the isotropic and anisotropic structure of the crust and mantle. Isotropic seismic models have been presented based on seismic reflection and