Project IPY n°8 SASSI : Synoptic Antarctic Shelf- Slope Interactions Study Involving a team of scientists from 11 countries, this project will measure the temperature, saltiness and flow speed of the water from continental shelf and slope, including under ice environments. This is something scientists know very little about, but the data are crucial for developing better global climate models. The few recent measurements we have suggest that the water close to Antarctica is getting fresher (less salty). But where is this extra fresh water coming from ? Only by measuring – especially during winter – the properties of the water and how fast it is flowing will we be able to understand the processes that are going on, and make sure that these are put into our climate models correctly. There has never been a concerted effort to make measurements on the Antarctic continental shelf and slope during the winter. IPY is enabling everyone to work together to make this happen, by leaving instruments on the sea bed and in the water for a year, even when the ice is covering the sea surface above them. Each nation is going to deploy instruments so that a circumpolar coverage can be obtained for the first time. As well gathering data during IPY, some of SASSI's instruments will be left in place after IPY, providing an important legacy for future research.