TASMANDRAKE Cruise, RV Hespérides

Abstract

The general objective of the TASMANDRAKE project is the study of the onset and evolution of the Antarctic Circumpolar Current (ACC). Taking into account the allowed period and that the capabilities of the geophysical equipment on board cannot image the deep structures and sediments, the cruise cannot fulfill the objectives of the TASMANDRAKE Project pertaining to the opening of gateways and onset of the ACC. We have therefore developed and alternative plan for the DRAKE2018 cruise that will allow us to collect mid-penetration to shallow data from the southern Drake-Scotia area (58ºS/62ºS and 60ºW/50ºW) and the South Orkney Shelf (60ºS/63ºS and 50ºW/40ºW). With this kind of capabilities we target those objectives of the TASMANDRAKE Project dealing with: 1) the evolution of the ACC during the Pleistocene and the Holocene; and 2) near-surface structure of continental blocks (i.e., the South Orkney micro-continent and the platform surrounding Elephant Island) and age of the older oceanic crust in Drake Passage. The proposed work is aimed to help land- ocean correlations between the stratigraphy of Seymour/Marambio Island and Ocean Drilling Project Site 696, in order to better understand the break-up and paleogeographic evolution of these continental blocks. The proposed marine surveys will consist in the execution of predefined transects along which geophysical data will be collected. In addition, we expect to collect sediment cores in specific sites, in order to groundtruth seismic facies with sediment information and provide age constrains of the most recent (Quaternary-Pliocene) units