I work on climate reconstructions from marine sediments and stalagmites (cave dripstones) with a variety of geochemical methods. Recently I have focused on novel techniques to reconstruct past temperatures, most importantly clumped isotope thermometry. This method takes advantage of the fact that the distribution of isotopes within molecules depends on the formation temperature. Our state-of-the-art equipment at the stable isotope facility Farlab is specifically targeting samples where only limited material is available. This allows us to apply the method to marine microfossils (foraminifera) in order to reconstruct temperature changes in the ocean across the last 65 million years (project DOTpaleo, funded by the Norwegian Research Council, and earlier projects C4T, funded by the European Research Council and CLIP, funded by the Trond Mohn Foundation).
In addition, with Yves Krüger we have established a technique that allows constraining growth temperatures of stalagmites by studying ancient drip water trapped as fluid inclusions within the calcite matrix. We have been using this and other methods to reconstruct tropical temperatures across the last half million years in the project T-TRAC, funded by the Norwegian Research Council, as well as on South African stalagmites in the framework of the SapienCE Center. Now we are further testing and developing the method in the project FluidMICS (funded by the ERC) to then apply it in different places in the tropics/subtropics and find out about the interplay between low and high latitude climate across the Quaternary.
Institutt for geovitenskap / Department of Earth Science
Realfagbygget, Allégt. 41