Ariadna Martínez-Dios

Summary

My PhD thesis is framed in the field of Paleoceanography and aims to explore past ocean conditions from the combination of two paleoarchives: sediment cores and cold water corals (CWC). My main objective is to experimentally calibrate specific elemental ratios including P/Ca, Ba/Ca, Cd/Ca, B/Ca, U/Ca and Li/Mg as proxies of nutrient dynamics, pH, carbonate ion concentration and temperature. To this end, I am currently working with the CWC species Desmophyllum dianthus under manipulative conditions of pH, T and nutrients in aquaria. These individuals, together with fossil specimens of D. dianthus, will be later analysed with Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICPMS) at Rutgers University (US). In parallel to the experiments, I analyse molecular biomarkers in marine sediment cores, including long chain alkenones, synthesized by a few phytoplankton species of the Haptophyta division, and which allow reconstructing sea surface temperatures and primary production in the past. This combined approach allows working with different resolutions and time scales and will ultimately help to assess the natural variability of ocean processes to better understand environmental changes caused by anthropogenic activity.

Aquatic & Marine Chemistry Biogeochemistry Climate Change Biology Ecology Marine Biology