This award will allow the PIs to continue the development of Thorium-230 profiling in marine sediments as a paleoceanographic tool. Th-230 flux to seafloor has been shown to be largely independent of particulate flux, but closely related to the rate of production in the water column. This property can be exploited to independently calculate sediment flux to the seafloor. Sediment trap work accomplished so far supports this model for modern sediment flux and in the next phase the work will be carried back to isotopic stage 5/6 in Southern Ocean.
