M.Sc. Arne Leider

My PhD-project is part of the “Multidisciplinary study of continental/ocean climate dynamics using high-resolution records from the eastern Mediterranean” (MOCCHA), which is incorporated into the EUROCORES Program and explores two sites in the Mediterranean for future IODP proposals. A near-coastal site at the Gallipoli shelf (Gulf of Taranto, S Italy) and a deep anoxic basin site in the mid Ionian Sea provide marine records suitable for high resolution climate reconstruction with better than 4-yrs resolution for at least the last 4000 years. The program investigates a suite of organic and inorganic chemical parameters, foraminiferal isotopes and elemental composition as well as palynological composition of the samples.
The near-coastal site at the Gallipoli shelf revealed high-frequency 11-year and centennial-scale cyclicity in the sediment based on stable carbon and oxygen isotope profiles of planktic foraminifera and alkenone based Sea Surface Temperatures, suggesting a relation to solar forcing. The multidisciplinary approach of MOCCHA aims at the calibration and development of current and new terrestrial and oceanic paleo-climate-related proxies and their application to older units.

The main aspects of the PhD project are:

1. Analysis of specific lipid biomarkers based on a network of surface sediment samples from the SW Adriatic Sea and the Gulf of Taranto obtained during CAPPUCCINO cruise 2006. The aim is to tune biomarker related proxies which integrate recent conditions such as Sea Surface Temperature, algal ecology, changes in land-sea interaction, hydrology and transport. Identification and quantification will be achieved by performance of GC-MS, –FID and HPLC-MS protocols. Source classification will be obtained using compound specific stable isotopic composition analysis of carbon and hydrogen (GC-IRMS). Temperature proxies that will be compared are the alkenone based UK’37 and tetraether lipid based TEX86 index. Terrestrial derived organic matter will be analysed using long-chained n-alkanes, lignins and applying the recently presented BIT index.

2. Application of the above mentioned proxies to time slices of the Holocene. The aim of this study is a lipid-based environmental reconstruction to further unravel the climate dynamics and forcing in this region. As an overlook the main features of the second part of this project, based on high-resolution analysis, are:

• temperature reconstruction of key cores

• lipid-based reconstruction of changes in the marine community

• lipid-based reconstruction of land-sea interactions on basis of profiles and n-alkane stable isotope analysis