Weekly Reports Polarstern

The Expedition PS10104 from Punta Arenas to Punta Arenas

How much and how fast will the global sea level rise in the next 100 or 200 years? One of the largest uncertainties in the prediction models is given by the role of the ice sheets, in particular that of West Antarctica which today is melting fast in some regions.  A complete melt-down of the West Antarctic Ice Sheet would result in a sea level rise of 3 to 5 meters. Indications that the ice sheet collapsed partially or completely during past warm times of the Earth come from numerical climate models and some geological data of marine sediments deposited in those warm periods.

Our POLARSTERN expedition PS104 starts on February 6th from Punta Arenas in southern Chile and is aiming for the continental shelf of the Amundsen Sea off West Antarctica. The mighty outlet glaciers into the Amundsen Sea, such as Pine Island and Thwaites glaciers, currently suffer from the largest ice mass loss in Antarctica. Has a possible collapse of the West Antarctic Ice Sheet always been initiated from this region during past warm times? By operating the remote-controlled seabed drill device MARUM-MeBo70, we want to collect drill cores from sediments that were deposited in relevant past warm periods. These sediments can provide records that show how far the ice sheet retreated during those times in which atmospheric conditions and ocean temperature were similar to today or predicted for the near future. Such knowledge will help to better understand the behaviour of the West Antarctic Ice Sheet during times of climate change and improve predictions for its future development. Closely related to the drilling program at selected sites we will conduct geophysical surveys to transfer the drill core results to a larger area. In addition, we will collect rock samples from the main land as well as geodetic data important to understand the land uplift caused by the ice mass loss. The helicopters of POLARSTERN support both land-based programs to study the past and present ice sheet development. They are, therefore, an excellent supplement to the drilling program from the ship.

We will take you along on an exciting and hopefully revealing expedition through our weekly reports and blogs.