Glacial Thrusts: Implications for the Crustal Deformation of the Icy Satellites

Abstract

The icy satellites of the outer Solar System show surfaces strongly deformed by tectonic activity, which mostly shows wide strike-slip zones. The structural pattern recognized on such regions can be ascribed to the deformation observed on terrestrial analogs identified in glaciers, whose flow produces deformation structures that bear key information to compare and better understand the surface and subsurface development of the structures identified on icy satellites. Multiscale analysis is used to acquire localand regional-scale datasets that are compared with icy satellite data. Glacier deformation structures are compared with those identified in a unique regional-scale investigation of the icy satellites. In this work, we present a review of the approach used for the comparison between glacial and icy satellite shear zone deformation. The comparison concerns thedeformation styles observed in these bodies, with a particular emphasis on compressional structures, called thrusts, which are hardly detected on icy satellites. Thrusts occur on glaciers and are important for glacial flow, deformation compensation and fluid circulation. Here, we report the occurrence of glacial thrust to better understand the icy environment under deformation and make inferences on icy satellite shear zones. Thanks to fieldwork and remote sensing analyses, we can infer the potential location and development of such compressional structures on icy satellites, which are pivotal for the compensation of their tectonics. We analyze glacial deformation by considering the icy satellite context and we discuss their potential detection with data from current and future planetary missions. A total of five categories of thrusts are presented to understand the best method for their detection, and a conceptual model on icy satellite surface and subsurface structural pattern is proposed.