Assessing the impact of land use and climate change on particulate metal transport to the oceans
Metals are transported to the oceans either as dissolved species in the water or as suspended particles. Suspended particles can affect biological activity and water quality and control dissolved species through various interactions, but also represent an important part of nutrient cycles and the carbon cycle. Data for rivers in NE Iceland suggest that the suspended material flux is much more dependent on discharge rate than are dissolved species, and thus more sensitive to climate change and land use. Dam construction on some of those rivers has filtered out the suspended particulate load, changing the nature and chemistry of the metals transported to the ocean, and providing a venue for determining the impact of changing particulate loads on metal transport.
This project will examine the natural elemental and isotopic variations accompanying seasonal changes in runoff prior to dam construction, and compare these with the present-day (post-dam) variations seen in both the dissolved and suspended particulate flux. This will allow assessment of the impact of dam construction, land use, and climate change on weathering in river catchments and on the elemental and isotope composition of material delivered to the ocean.