Abstract

The primary aim of the Weddell Sea Expedition 2019 was to investigate the fluctuating extent and glacial history of the Larsen C Ice Shelf, together with the sea ice, oceanography and marine biology close to it, as part of an interdisciplinary science programme led by the Scott Polar Research Institute. The Weddell Sea and Larsen Ice Shelf were selected for investigation because of the known instability of ice shelves in this area, including the recent calving of the huge iceberg A68 , and the significance of the area for sea-ice and dense bottom-water formation. The expedition platform was the South African icebreaker Agulhas II, which was equipped with a number of scientific instruments including two state-of-the-art autonomous underwater vehicles (AUVs). The initial findings of the expedition, including geophysical observations of past ice-shelf grounding lines imaged in unprecedented detail, will be presented. A second expedition aim was to use the AUVs to search for the wreck of Sir Ernest Shackleton’s ship Endurance which was crushed by sea ice and sank in the Weddell Sea during the Imperial Trans-Antarctic Expedition (1914 – 1917). A century later the sea-ice conditions in the western Weddell Sea remain just as challenging, but in early 2019 the Agulhas II managed to penetrate this remote region to search for the wreck, whose position was known from historical theodolite and sextant measurements held in the archives of the Scott Polar Research Institute. The search for Endurance will also be outlined.