Changes in the proglacial landscape of the Antarctic Peninsula and sub-Antarctic islands during the 21st century

Proglacial systems are among the most dynamic landscapes on Earth and are important habitats and sources of nutrients. They are predominantly shaped by the interplay of meltwater from glaciers and sediment supplied by slope failures. This thesis describes the composition and ever-evolving dynamics of the Antarctic Peninsula and sub-Antarctic islands’ proglacial environment, making use of remote sensing and field techniques. First, a land cover map of major proglacial sites is presented with ten land cover classes describing the extent of water, sediment, bedrock, and vegetation at 30 m spatial resolution (77 % accuracy). Vegetation and coarse/wet sediment are observed to be more abundant in northerly sites. Building on this, change-vector analysis is used to investigate how Antarctic proglacial regions have evolved in the 21st Century (80 % accuracy). Ice loss is shown to be a key driver of land cover change, with extensive change occurring on South Georgia and Alexander Island, where melt was widespread. An analysis of river water discharge and sediment transport from two neighbouring catchments on Ulu Peninsula, James Ross Island, is also presented. Stream monitoring and provenance techniques highlight that catchments on James Ross Island are sensitive to changes in air temperature (specifically in melting ice and snow) for their water delivery, whilst the supply of sediment is largely controlled by underlying lithology. Finally, the role of recent warming (0.24 ± 0.08 ᵒC yr⁻¹) on deglaciation on the James Ross Archipelago between 2010 and 2023 is described. Over this period, the rate of glacier area reduction increased six-fold, and glacier ablation prevailed (up to -1.5 m yr⁻¹). Together, these findings highlight that glaciers and proglacial systems are rapidly changing in the Antarctic Peninsula and sub-Antarctic, and further research is required to understand how the interaction between these systems will affect the future evolution of its glaciers, landscape, and habitats.