Intensified coupling between the East Antarctic Ice Sheet and the Antarctic Circumpolar Current during the Late Miocene

Recent work indicates that the Southern Ocean underwent major reorganisation during the Late Miocene, culminating in the establishment of a modern-like Antarctic Circumpolar Current (ACC). Understanding how changes in ACC dynamics interact with Antarctic ice-sheet behaviour is essential for constraining past ocean–ice feedbacks and for assessing the sensitivity of marine-based sectors of the Antarctic Ice Sheet to future warming. Here, we present new mean sortable silt records from ODP Site 1192 in the South Atlantic Ocean and ODP Site 744 in the South Indian Ocean, both located along the main pathway of the ACC and spanning the past ~18 million years. These records are combined with neodymium isotope compositions (ε_Nd) of fine-grained (<63 μm) detrital sediments from ODP Site 1165, situated on the continental rise off Prydz Bay, East Antarctica, providing complementary constraints on ACC strength, sediment transport, and ice-sheet dynamics. Our results indicate that the development of a vigorous, modern-like ACC during the Late Miocene coincided with a major reorganisation of the ice sheet in the Prydz Bay sector, marking a transition toward a more dynamic ice-sheet state. Overall, our data suggest that oceanic forcing became increasingly important following the establishment of modern-like ACC conditions, highlighting intensified ocean–ice interactions since the Late Miocene.