Rolf-Martin Vieten

e-mail: rolf-martin.vieten@upr.edu               

• Hometown: Celle, Germany

• Previous Education: Leibniz University of Hannover

• Degree obtained:  B.S. and M.S. in Earth Sciences

• Research Interest: Speleothems as climate archives; reconstructing paleoclimate using geochemical proxies; interaction between atmosphere, ocean circulation and hydrosphere; droughts in mesoamerica and community vulnerability; understanding sedimentary processes in underground environments.

My Ph.D. project focuses on the reconstruction of the hydrological variability of the late Holocene in the Caribbean. Primarily I am going to use speleothems, which have been collected in Puerto Rico, Guatemala, Venezuela and Cuba. The selected speleothems are promising proxies for a high resolution climate reconstruction, because their composition varies nearly annually. First the growth rate is modeled using U/Th ages. With a precise age model I will be able to compare the speleothem data to other proxies in the Caribbean, such as the sediments in the Cariaco Basin. The Oxygen-Isotope-Composition in the speleothems is primarily driven by the amount of rainfall. High resolution sampling of the speleothems will produce a detailed δ18O record.

In order to interpret the measured δ18O-values correctly, the processes acting on the rainwater when it passes through the soil until it reaches the speleothem have to be understood.  Cave systems in Puerto Rico are going to be monitored to verify how the rainwater is affected on its way through the soil until it reaches the cave deposits. The monitoring includes sampling of rain and drip water, as well as the installation of weather stations in and above the caves.

A better understanding of the hydrological variability in the Caribbean is of great importance to predict the future redistribution of water resources. Furthermore the results will be used to improve the knowledge about the ocean-atmosphere interaction of the Atlantic and Pacific, due to the location of the Caribbean between both oceans.