Late Pleistocene and Holocene climate forcing on the Baltic Sea

Field: Miljövetenskap
Project leader: Thomas Andrén
Starting year: 2015
Project type: Project

During autumn 2013 the first ever scientific drilling expedition in the Baltic Sea was carried out within the International Ocean Discovery Program IODP Expedition 347, Baltic Sea Paleoenvironment .

The overarching objective of Expedition 347 was to gain a deeper understanding of the paleoenvironmental evolution of the Baltic Sea Basin through the last glacial cycle.

After the expedition, the following Onshore Science Party in early spring 2014 carried out visual inspection and description of the cores retrieved, measurements of physical properties, and intense sampling of the cores. Initial biostratigraphic and lithologic analyses provided a preliminary chronology that, together with the visual appearance of the sediment, was used as a guide for further sampling.

In general, the expedition was very successful and all of the research themes formulated in the original proposal will be explored and the objectives met. The project presented here is designed as two integrated sub-projects with the following overarching aims:

• To better constrain the model of the Scandinavian Ice Sheet with its global and regional isostatic and eustatic impacts.

• To investigate how Baltic in- and outflows have varied over time and how these variation are related to changes in large-scale atmospheric circulation and changing sea levels (threshold depths).

• To determine the main mechanisms behind hypoxia-driving processes in the Baltic and to what degree human activities have played a role.

Expected outcome

It is envisaged that answering these research questions it will allow us to gain totally new scientific insights in a variety of research fields such as e.g.

• regional and global issues on the timing and forcing of rapid climate change and sea levels

• glacial history of the Scandinavian ice sheet and its inter-action with the climate system

• mechanisms behind hypoxia-driving processes in intra-continental type of sea basins

The Off- and Onshore Science Party consist of 30 specialist scientists from Europe, USA, Japan, China, Australia and New Zeeland and were selected in a strong international competition. In addition to the Co-chief Scientist Thomas Andrén another two Swedes were selected of which the siliceous microfossil specialist Elinor Andrén is also from Södertörn University. Hence Södertörn University scientists play a leading role in the Science Party.

Final report_ThomasAndrén_Late Pleistocene and Holocene climate forcing on the Baltic Sea