Evolution of hydrogen isotopes of a Mid-Cenozoic sediment core
The evolution of seawater isotopes reveals information of evaporation/ precipitation, ice volume, salinity, and temperature. Stable oxygen isotopes of carbonate shells, e.g. of foraminifera, are a great tool in paleoceanography however their ratio is mainly temperature related, while stable hydrogen isotopes of Biomarker (organic compounds e.g. alkenones) are not temperature related and mainly salinity and sea water isotope dependent. Combining the information of both seawater isotope proxies contributes to a better understanding of paleoceanographic parameters, linked processes, and the reconstruction of the past climate evolution.
Aim of the student project is to reconstruct the evolution of the hydrogen isotopic composition of the ancient sea water on a deep-sea sediment core spanning the Mid-Cenozoic and compare to existing proxy records e.g. oxygen isotope and temperature.
The Cenozoic spans the ice-free greenhouse time where we expect high evaporation rates followed by the tipping-point Eocene-Oligocene-Transition (EOT) with a climate shift towards an icehouse. The Antarctic ice sheet builds up slowly and changes in ice volume, sea level and temperature are recorded in the global benthic δ18O stack. During the Oligocene the Drake Passage formed, playing a major role in the Antarctic and global ocean circulation, followed by a major deep ocean cooling trend during the Miocene. Further cooling and formation of the Arctic ice cap and extensive glaciation over Greenland took place during the Pliocene.
Methodological focus will be:
- Extraction of sediment samples
- Identification of biomarker (GC-FID, GC-MS)
- Compound specific stable hydrogen isotope measurements of biomarker lipids such as alkenones (GC-TC-irMS)
- Data comparison of hydrogen isotopes with proxy records (further organic temperature proxies, δ18O, δ13C measurements could be added)
- Literature research
The student should be interested in paleoceanography, marine sediment proxies, stable isotopes and have a basic knowledge of the Cenozoic Era and climate evolution.
We are looking for a highly motivated MSc student with a background and keen interest in earth sciences and geochemistry. This project has a minimum stay of 2 months at NIOZ, Texel. The student will gain experience in the field of isotope geology, mass spectrometry, reporting scientific research. The earliest possible start date for this project is November 2022.
For further information, please contact Katrin Haettig (firstname.lastname@example.org).