Short presentation

I am a geologist and palaeoclimatologist using geochemical techniques to reconstruct climate and environmental conditions through Earth's history.

To do this, I analyze stable isotopes of sediments and sedimentary rocks and, especially, the carbonate shells of fossils (e.g. bivalves, belemnites, brachiopods, corals). I use the oxygen isotopes generated to reconstruct the seawater temperatures from the times in which the fossils lived, and using carbon isotopes, it is possible to reconstruct the CO₂ content of the seawater/atmosphere system for the same times.

The results allow reconstruction of natural climate fluctuations as well as changes in environmental conditions in the geological past over time spans of several tens of thousands to several hundred million years; including for mass extinction events (e.g. Permian/Triassic, Triassic/Jurassic, Cretaceous/Paleogene boundaries).

In my research projects, I have demonstrated that fundamental changes in atmospheric CO₂ took place in the Triassic, and that the end of the Late Paleozoic glaciation occurred in the earliest Permian. Furthermore, I was able to show that the mass extinction at the Permian/Triassic boundary was closely related to a volcanic event of enormous magnitude (Trap volcanism), during a period of enhanced continental weathering. 

What is notable about my results is that – even if often parallel trends exist – at certain times in the Earth's history, temperature fluctuations do not correlate with CO₂ variations. For example, a severe climatic cooling in central and northern Europe during the earliest Middle Jurassic (Aalenian) appears to have been caused by a sudden cut-off of an ocean current (similar to today's Gulf Stream) at that time by a tectonic event (uplift of the North Sea dome by uplift of the asthenosphere). This switched off the oceanic heat transport from low to high latitudes and central and northern Europe cooled down. We were further able to show that during the Eocene – one of the hottest periods in Earth's history – the North Sea temporarily reached Arctic temperatures. This was potentially also in connection with intense volcanic activity and the effects of other volcanic gases such as SO₂.

CV

ACADEMIC  QUALIFICATIONS: 

Dipl. Geol.:
Ruhr-University Bochum, Germany, 1993.

Ph.D.:
Ruhr-University Bochum, Germany, 1999 (Dr. rer. nat.).
Entitled "⁸⁷Sr/⁸⁶Sr-, d¹⁸O- und d¹³C-Evolution des triassischen Meerwassers: Geochemische und stratigraphische Untersuchungen an Conodonten und Brachiopoden"

Habilitation:  
Freie Universität Berlin, Germany, 2008 (Priv. Doz).
Entitled "Seawater isotope variations during the Permian and at the Permian-Triassic boundary: Clues for palaeoclimate and environmental impacts"



EMPLOYMENT  HISTORY:

1994-1999:   Ruhr-University Bochum, Germany, scientific assistant
1999-2001:   Ruhr-University Bochum, Germany, scientific assistant
2001:           Netherlands Institute for Sea Research; Texel, Netherlands, res. fellow
2001-2002:   University Innsbruck, Austria, research fellow
2002-2004:   Ruhr-University Bochum, Germany, scientific assistant
2004-2006:   University of Oxford, U.K., research fellow 
2006-2009:   Freie University Berlin, Germany, scientific assistant
since 2009:   Copenhagen University, Denmark, Associate Professor