Research and visualisation of the submarine relief of the Argentine Islands (Western Antarctica) using GIS methods

The aim of this study is to investigate the geomorphological structure and genesis of the submarine relief under the influence of morphogenetic factors within the sub-Antarctic shelf area near the Argentine Islands, where the ‘Akademik Vernadskyi’ Ukrainian Antarctic Station is located. The research is based on the construction and analysis of a digital seafloor model using GIS tools. The primary data for constructing the digital terrain model (DTM) of the studied water area were bathymetric maps from the British Admiralty (Admiralty Surveys of the UK), along with maps constructed based on echo-sounding (boat-based) depth surveys. The database covers an area of 5.6 km² and includes 760 data points. The 3D model was created using ArcGIS software and Surfer 10. The model provides a clear illustration of the surface relief formed under the influence of endogenous and exogenous geological processes. The Argentine Islands are considered a horst, bounded by a fault. The model reveals the fault-scarp nature of the main fault that separates the Argentine Islands horst from the Penola Strait, as well as horizontal ledges of large blocks and second-order step-faulted blocks that complicate the displacement surface, small transverse depressions with suspension flow deposition cones. In the underwater relief, the straits between the islands appear as shallow, linear depressions oriented parallel and perpendicular to the marginal fault. Their formation resulted from the combined influence of primary tectonic factors and secondary glacial erosion processes. It is likely that these depressions were initially formed under terrestrial conditions due to glacial erosion by descending glaciers moving toward the deep strait during the Quaternary glaciation, when sea levels were significantly lower. The applied method of three-dimensional modelling has proven to be an effective tool for visualising the features of the submarine relief. The generated digital terrain models clearly reveal fine-scale elements of the seafloor morphology that are not readily discernible from conventional bathymetric maps.