Understanding the drift of Shackleton's Endurance during its last days before it sank in November 1915, using meteorological reanalysis data

Abstract. On 5 December 1914, Sir Ernest Shackleton and his crew set sail from South Georgia aboard the wooden barquentine vessel Endurance, beginning the Imperial Trans-Antarctic Expedition to cross the Antarctic continent. However, Shackleton and his crew never reached land because the vessel became beset in the sea ice of the Weddell Sea in January 1915. Endurance then drifted in the pack for 11 months, was crushed by the ice, and sank on 21 November 1915. Over many years, various predictions were made about the location of the wreck. These were based largely on navigational fixes taken by Captain Frank Worsley, the navigator of the Endurance, 3 d prior to and 1 d after the sinking of Endurance. On 5 March 2022, the Endurance22 expedition located the wreck some 9.4 km southeast of Worsley's estimated sinking position. In this paper, we describe the use of meteorological reanalysis data to reconstruct the likely ice drift trajectory of Endurance for the period between Worsley's final two fixes, at some point along which the vessel sank. Reconstructions are sensitive to choices of wind factor and turning angle, but allow an envelope of possible scenarios to be developed. A likely scenario yields a simulated sinking location some 3.5 km from the position at which the wreck finally was found, with a trajectory describing an excursion to the southeast and an anticlockwise turn to the northwest prior to sinking. Despite numerous sources of uncertainty, these results show the potential for such methods in marine archaeology.