TY - JOUR

T1 - The Evolving Paleobathymetry of the Circum-Antarctic Southern Ocean Since 34 Ma

T2 - A Key to Understanding Past Cryosphere-Ocean Developments

AU - Hochmuth, K.

AU - Gohl, K.

AU - Leitchenkov, G.

AU - Sauermilch, I.

AU - Whittaker, J. M.

AU - Uenzelmann-Neben, G.

AU - Davy, B.

AU - De Santis, L.

N1 - Funding Information: The authors thank the numerous scientists, technicians, and ship crews involved in the acquisition and processing of the seismic reflection data as well as the data curators at OGS Trieste for providing their services within the SCAR Antarctic Seismic Data Library System (SDLS). Additional data have been provided by Geoscience Australia, Spectrum Geo Ltd. This project has been funded by the Deutsche Forschungsgemeinschaft (DFG) under Projects GO724/15-1 and GO724/-2, and institutional resources from the Research Program PACES-II, Workpackage 3.2, of the Alfred Wegener Institute. The project contributes to the SCAR Scientific Research Program ?Past Antarctic Ice Sheet Dynamics? (PAIS). I.S. was supported under the Australian Research Council's Special Research Initiative for Antarctic Gateway Partnership (Project ID SR140300001). K.H. further acknowledges the ?Visiting Scholarship? scheme of the University of Tasmania, funding a 3-month research visit at the University of Tasmania. J.M.W. acknowledges funding from the Australian Research Council DP180102280. B.W.D. acknowledges funding support from the New Zealand MBIE for the Zealandia research programme. G.L. acknowledges the Russian Science Foundation Grant 16-17-10139. The authors would like to thank Emerson E&P Software, Emerson Automation Solutions, for providing licenses for the seismic software Paradigm in the scope of the Emerson Academic Program. The authors thank two anonymous reviewers for their enthusiastic and helpful comments, which improved the manuscript and the Pangaea data editors for their help with the publication of the paleobathymetric and isopach data sets. Publisher Copyright: ©2020. The Authors. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2020/8/1

Y1 - 2020/8/1

N2 - The Southern Ocean is a key player in the climate, ocean, and atmospheric system. As the only direct connection between all three major oceans since the opening of the Southern Ocean gateways, the development of the Southern Ocean and its relationship with the Antarctic cryosphere has influenced the climate of the entire planet. Although the depths of the ocean floor have been recognized as an important factor in climate and paleoclimate models, appropriate paleobathymetric models including a detailed analysis of the sediment cover are not available. Here we utilize more than 40 years of seismic reflection data acquisition along the margins of Antarctica and its conjugate margins, along with multiple drilling campaigns by the International Ocean Discovery Program (IODP) and its predecessor programs. We combine and update the seismic stratigraphy across the regions of the Southern Ocean and calculate ocean-wide paleobathymetry grids via a backstripping method. We present a suite of high-resolution paleobathymetric grids from the Eocene-Oligocene Boundary to modern times. The grids reveal the development of the Southern Ocean from isolated basins to an interconnected ocean affected by the onset and vigor of an Antarctic Circumpolar Current, as well as the glacial sedimentation and erosion of the Antarctic continent. The ocean-wide comparison through time exposes patterns of ice sheet development such as switching of glacial outlets and the change from wet-based to dry-based ice sheets. Ocean currents and bottom-water production interact with the sedimentation along the continental shelf and slope and profit from the opening of the ocean gateways.

AB - The Southern Ocean is a key player in the climate, ocean, and atmospheric system. As the only direct connection between all three major oceans since the opening of the Southern Ocean gateways, the development of the Southern Ocean and its relationship with the Antarctic cryosphere has influenced the climate of the entire planet. Although the depths of the ocean floor have been recognized as an important factor in climate and paleoclimate models, appropriate paleobathymetric models including a detailed analysis of the sediment cover are not available. Here we utilize more than 40 years of seismic reflection data acquisition along the margins of Antarctica and its conjugate margins, along with multiple drilling campaigns by the International Ocean Discovery Program (IODP) and its predecessor programs. We combine and update the seismic stratigraphy across the regions of the Southern Ocean and calculate ocean-wide paleobathymetry grids via a backstripping method. We present a suite of high-resolution paleobathymetric grids from the Eocene-Oligocene Boundary to modern times. The grids reveal the development of the Southern Ocean from isolated basins to an interconnected ocean affected by the onset and vigor of an Antarctic Circumpolar Current, as well as the glacial sedimentation and erosion of the Antarctic continent. The ocean-wide comparison through time exposes patterns of ice sheet development such as switching of glacial outlets and the change from wet-based to dry-based ice sheets. Ocean currents and bottom-water production interact with the sedimentation along the continental shelf and slope and profit from the opening of the ocean gateways.

KW - glacial sedimentation

KW - ice sheet

KW - ocean gateways

KW - paleobathymetry

KW - Southern Ocean

UR - http://www.scopus.com/inward/record.url?scp=85089853259&partnerID=8YFLogxK

U2 - 10.1029/2020GC009122

DO - 10.1029/2020GC009122

M3 - Article

AN - SCOPUS:85089853259

VL - 21

JO - Geochemistry, Geophysics, Geosystems

JF - Geochemistry, Geophysics, Geosystems

SN - 1525-2027

IS - 8

M1 - e2020GC009122

ER -