Shallow crustal velocity structure and tectonic significance beneath Fildes Peninsula, West Antarctica

Abstract Fildes Peninsula is the most exposed area of King George Island, Antarctica, which has experienced frequent volcanic activities, and its strata are composed mainly of basalt and pyroclastic rocks, making it an ideal location for conducting scientific research in Antarctica. This study provides the first constraints on the shallow crustal structure of the peninsula through ambient noise tomography and horizontal-to-vertical spectral ratio (HVSR) analyses by utilizing a denser array of short-period portable seismometers deployed on Fildes Peninsula. The results indicate that the sediment layers on the peninsula are very thin and reveal inhomogeneity within the shallow crust of the study area, which may be related to the characteristics of the surface geological structure. Consistent with crustal activity characteristics observed in most volcanically active regions around the globe, the shallow layers in the study area exhibit predominantly negative radial anisotropy. Our results provide an important imaging basis for the study of shallow crustal structure and deformation on Fildes Peninsula.