Southwest Atlantic intermediate and deep water circulation : 20,000 years of water mass re-organization and current strength variability

Abstract

As one of the major players of the Atlantic meridional overturning circulation, the deep southern component water (SCW), comprising Lower Circumpolar Deep Water (LCDW) and Antarctic Bottom Water (AABW), ventilates the deep waters and influences global climate. However, detailed information about deep SCW strength are lacking, due to its corrosivity resulting in a lack of appropriate paleoceanographic archives. In order to improve the accuracy of ocean circulation variability, detailed deep SCW reconstructions require additional efforts from many branches of climate research. In the frame of this thesis, seven radiocarbon-dated Sediment cores from the Argentine continental margin (i.e. from contourite deposits, the Mar del Plata Canyon and the deep slope) were investigated. The core sites provide the opportunity to investigate the intermediate and deep water mass circulation, e.g. deep SCW flow strength variations, of the deep Southwest Atlantic during the last 20 ka. Furthermore, part of these sediment cores were used to analyze the influence of intermediate and deep ocean currents on sedimentary processes within a blind canyon system.