The Evolving Paleobathymetry of the Circum-Antarctic Southern Ocean Since 34 Ma: A Key to Understanding Past Cryosphere-Ocean Developments

The Southern Ocean is a key player in the climate, ocean and atmospheric system. As the onlydirect connection between all three major oceans since the opening of the Southern Oceangateways, the development of the Southern Ocean and its relationship with the Antarcticcryosphere has influenced the climate of the entire planet. Although the depths of the oceanfloor have been recognized as an important factor in climate and paleoclimate models,appropriate paleobathymetric models including a detailed analysis of the sediment cover arenot available. Here, we utilize more than 40 years of seismic reflection data acquisition alongthe margins of Antarctica and its conjugate margins, along with multiple drilling campaigns bythe International Ocean Discovery Program (IODP) and its predecessor programs. Wecombine and update the seismic stratigraphy across the regions of the Southern Ocean andcalculate ocean-wide paleobathymetry grids via a backstripping method. We present a suiteof high-resolution paleobathymetric grids from the Eocene-Oligocene Boundary to modern