Calibration and reconstruction of Holocene variability of water mass properties inferred from stable isotopes in foraminifers

Contact:Dr. Robert F. Spielhagen

Isotopic and geochemical analyses and abundances of fossil foraminifera are common tools for paleoceanographic reconstructions. Oxygen isotopic (d18O) records of sediment cores provide information about variation in sea surface temperatures and salinities in the past, while carbon isotopic (d13C) records refer to e.g., paleoproductivity and stratification.

This study intends to improve the understanding of the correlation between recent oceanic variability and the composition of shells of living calcareous microorganisms. This is important for a correct interpretation of fossil stable isotope data. The aim of our calibration study is to investigate how in-situ conditions like salinity, temperature, and stable isotopic ratios of the ambient water are reflected in the tests of living foraminifera (further information).

Furthermore, marine sediment cores from the Nordic Seas and the adjacent Arctic are investigated in order to reconstruct the paleoceanographic and paleoclimatic variability in this area. The main focus lies on the variability of water masses, currents and sea ice cover during the last 10,000 years. To determine the maximum range of natural variability, the last glacial-interglacial transition is also included in these studies (further information).  

The project is funded by the European Commission (CORDIS) within the CASE (The Changing Arctic and Subarctic Environment) Initial Training Network. All investigations are performed in close cooperation with CASE ITN partners and researchers in the other work packages.