Nearshore Seafloor Depositions and Deformations at Paleo-Glacier Active Area revealed from side scan sonar data, case study from Horseshoe Island, Western Antarctica

Abstract. The variety of geophysical imaging methods, such as shallow-acoustic profiling, multi-beam swath bathymetry, and side scan sonar, has made it possible to recognize and understand submerged glacial landforms on and below the seafloor of historically glaciated continental edges. By examining these landforms, one can learn more about the dynamics of paleo ice sheets and the processes by which ice sheets move, erode, and deposit sediment. In order to evaluate model projections of the future responses of the Greenland and Antarctic ice sheets to climate change, it is equally crucial to comprehend previous rates of change. In order to accomplish this, the video ground-trothing and side scan sonar data, which are the initial dataset for the study area, were used to map the nearshore deformations and deposition features of Western Horseshoe Island, Western Antarctica. The morphological and erosional boundaries indicate that streams of melting ice have affected the seafloor, especially below 10 meters, in the recent past, forming glacial marine phases and ice-margin. Nonetheless, a limited area also revealed subglacial seafloor features, such a paleolake, and paleoshoreline morphology, suggesting the presence of a two-phase mechanism in the study area. Meltwater streams and ice flow directions in the research region generally trend southward, with the island's southernmost portion being deeper than its westernmost component.