Summary

After 11 drill holes and numerous operations of conventional sediment coring, seismic and aeromagnetic surveying, geothermal temperature probing, bathymetric and sub-bottom profiling, hard rock sampling on the mainland and islands, and the measurements of geodetic survey points, we can proudly look to our achievements in terms of sample collection and data acquisition. Whether the samples and data are sufficient enough to address the ice sheet dynamics of this Antarctic sector will only be known after thorough analysis back in our institutes. But we have already good indications for interesting results after a first glance at the samples and data on board. For instance, we know that we drilled – for the first time in this West Antarctic region – sedimentary rocks from the time before the first ice sheet grew in West Antarctica, thus, from a very warm period. Other drill cores reveal sediments from youngest deposits from meltwater pulses of the Pine Island Glaciers, alternating with marine deposits that will help determine the ages of the depositional processes and melt history of the glacier. We also drilled sediments from a presumable former sub-glacial lake. It now depends on the detective-like lab work to extract the relevant information from the climate archives in these sediments in context with the geophysical data so that the past dynamics of the West Antarctic Ice Sheet can be reconstructed.

All of our work on board was only possible because of the excellent crew of Polarstern under the leadership of Captain Schwarze. We are grateful to the crew who brought us safely through previously uncharted areas, helped deploying and retrieving our gear, and who made our time on board very pleasant with tasty meals and a friendly atmosphere. We also thank the helicopter crew who made the numerous flights to the mainland, islands and along aeromagnetic survey tracks possible.

We arrived in Punta Arenas this Saturday’s morning and have to take care of some loading work. Most of us will depart on Monday for our long journey back home – some will spend a few days vacation.

In the name of all expedition participants, I am sending you the best regards and wishes.

Karsten Gohl

(Chief Scientist of Expedition PS104)