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Mathias Feldtmann

Doktorand_innen

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+49 421 218-65982

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UFT, room 1560

Mathias Feldtmann
Institution: University of Bremen
Other webpage(s): Mathias' MARUM web page

 

PhD project:

Deciphering the climate of the Greenhouse world 45 million years ago – Closing the Mid-Eocene time scale gap

The climate of the earth is not stationary, but facing constant changes. Throughout the Cenozoic, the Earth switched between greenhouse and icehouse conditions. The middle Eocene was a period of substantial upheavals; the warm world of the early Paleogene cooled down, which eventually led to the onset of glaciation during the early Oligocene.

We know that periodic variations in the Earth’s orbit like the precession of the Earth’s axis with respect to the solstices, the angle between its equatorial plane and orbital plane (obliquity) and the shape of the Earth’s orbit (eccentricity) - the so called ‚Milankovitch cycles’, have an influence in the total and relative distribution of insolation. These variations are correlated with climate fluctuations which in turn influence biological, oceanographic or atmospheric processes, Within marine sediments, variations in proxies like stable isotopes can therefore be traced back to the changes in Earth’s orbit.

Since we know the frequency of the cycles (several 10,000 years to millions), we can use the imprint of the orbital parameters to set up an astronomical time scale.

My PhD thesis will deal with the age calibration of the Middle Eocene. Significant efforts were made in the past and the main part of the Cenozoic has already been astronomically tuned. However, there is still a prominent gap around the Mid-Eocene which, when closed, allows us to extend a complete orbital time scale back to the Mesozoic and to anchor the floating time scale of the Paleogene.
For this purpose. I will use sediment samples from IODP Expedition 342, Site 1408 off Newfoundland. These show an excellent preservation of microfossils and a substantially high sedimentation rate.
I will generate a high-resolution time series of planktic foraminiferal stable oxygen and carbon isotopes to decode the orbital parameters and obtain a tuned age model. Furthermore, the oxygen and carbon isotope values derived from Site U1408 provide important information about the formation of deep-water and its flow patterns as well as primary production. The high-resolution isotope time series are ideally suited to detect even high frequency patterns in changing climatic and oceanographic conditions.
This project is part of the Eocene Stable Isotope Consortium, an international cooperation to decipher the paleoceanographic evolution of the North Atlantic during the Eocene and improve the cyclostratigraphic time scale.

Thesis committee:

Prof. Dr. Heiko PälikeUniversity of Bremen
Dr. Thomas WesterholdUniversity of Bremen
Prof. Dr. Michael SchulzUniversity of Bremen
Dr. David de VleeschouwerUniversity of Bremen