Large scale maps of sediment thicknesses are essential prerequisites for the next generation of high resolution paleobathymetric reconstructions. In addition, maps of sediment thicknesses on continental margins are useful for studies of terrigenous sediment supply and sediment distribution on the ocean floor. Based on a compilation of more than 10000 km of single and multichannel seismic reflection data and correlations with ocean drilling sites, we model isopach grids of the Southern Pacific margin of West Antarctica. Following recent seismic stratigraphic models, we differentiate between "pre-glacial" and "glacially transported" sediments. The subsequent modelling of sediment thickness grids allows us to compare the pre-glacial and glacial sedimentary development in the study area. Based on available drillhole dates, we estimate the onset of accumulation of glacially transported sediments to have occurred at about 10 Ma, based on approximate sediment deposition rates. The thickest glacial sediment accumulations occur in front of major glacial drainage outlets, i.e. Marguerite Trough on the western Antarctic Peninsula margin, Belgica Trough in the Bellingshausen Sea, and the trough off Pine Island Bay in the Amundsen Sea. Sedimentation rates between 140 and 170 m/m.y. are calculated for these sites.
Helmholtz Research Programs > MARCOPOLI (2004-2008) > MAR2-Palaeo Climate Mechanisms and Variability