Marine particles act as carriers transporting trace elements from the continents to the ocean. Many of the trace elements are necessary for the marine ecosystems and thus the particle transport is a key factor for Arctic marine life. Climate change is suggested to increase the supply of carbon, nutrients and trace elements from continental sources into the Arctic Ocean. This project aims to provide information on transport of particles from the continental shelf areas of the Eurasian Arctic into the central Arctic basins, where settling through the water column and sedimentation occur.

Water samples were collected using a large-volume sampler followed by filtration. Particles were collected using pumps lowered to the selected depth where water, several hundred litres, was passed through the filter.

We will now examine the water samples by using radioactive thorium (Th) and protactinium (Pa) isotopes to study the transport of small particles and investigate their role in the biogeochemical cycling across the Arctic Ocean. The laboratory analyses of Th and Pa isotopes will result in detailed vertical resolution of their isotope distribution. This distribution will provide insight into the fate of particles transported from continental sources to the Arctic and their impact on trace elements.