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9th SCAR Open Science Conference and XXXVI SCAR Meetings. Hobart, Tasmania, Australia. 31 July - 11 August 2020, The Southern Ocean (SO) is an active regulator of global climate through its influence on the modulation of the global ocean circulation, the phytoplankton productivity as well as nutrient cycles, the transfer of energy and gas between the ocean and the atmosphere, and sea level. Despite its importance, seasonal and sparse distribution of instrumental data across the SO prevent a robust assessment of the physical and biological response and feedback on future climate change. Paleoclimate data are therefore essential to document the natural variability of environmental conditions and identify their drivers from decadal-to-millennial timescales. However, in paleoclimate studies, several questions remain unaddressed due to the lack of robust proxy calibration. While some tools are better constrained than others, the mechanisms controlling them are not fully understood. A critical step to improve their use is to conduct a systematic multi-annual collection of samples and data throughout the SO. ICEPRO has been initiated to strengthen existing collaborations and creating new connections among several partners regularly crossing through different transects the SO and who have the opportunity to sample the water column and marine sediments spanning at least the last 2,000 years. Such collaborative work could therefore cover most of the important regions of the SO, thus allowing a better monitoring of modern environmental and hydrological conditions, and ultimately improve calibration of tools commonly used for paleoreconstructions. Here we aim to present ICEPRO, its first steps and results we obtained from the last Antarctic cruises as well as our future ambitions.

The Ross Sea, located between Victoria Land and Marie Byrd Land in Antarctica, is one of the main drainage of the Antarctic Ice Sheet (AIS). Reflection seismic data acquired by many countries during several decades have provided insights into the history of the Ross Sea and the AIS evolution. However the majority of the existing seismic data are concentrated in the shelf area, where hiatus formed by grounding ice sheet erosion multiple events prevent to reconstruct the entire sedimentary sequences depositional evolution. On the outer shelf and upper slope, the sedimentary sequences are relatively well preserved. The main purpose of this study is the investigation of the Cenozoic Antarctic Ice Sheet evolution through the seismic sequence analysis of the outer shelf and slope of the Central Basin, in the Ross Sea. The data used are the new multi-channel seismic data, KSL12, were acquired on the outer shelf and upper slope of the Central Bain in February 2013 by Korea Polar Research Institute. The reflection seismic data, previously collected by the Italian Antarctic Program (PNRA) and other data available from the Seismic Data Library System (SDLS) are also used for velocity tomography and seismic sequence mapping. The seismic data were processed by a conventional processing flow to produce the seismic profiles. Preliminary results show well-developed prograding wedges at the mouth of glacial troughs, eroded by a major glacial unconformity, the Ross Sea Unconformity 4 (RSU-4), correlated to a main event between early- and mid-Miocene. The velocity anomalies shown along KSL12-1 can be interpreted as showing the occurrence of gas and fluids, diagenetic horizons and sediment compactions. The isopach maps of each sequence show the variation of thickness of the sediments depocenter shift. The seismic sequence stratigraphy and acoustic facies analysis provide information about different phases of ice sheet’s advance and retreat related to the AIS Cenozoic dynamics.