CAREER: Disentangling the controls and impacts of sedimentary iron cycling across Alaskan continental shelves

This research will examine how iron cycles on northern Alaskan shelves. Iron in Arctic sediments can play a key role in how nutrients and other elements, including toxic trace metals and economically critical metals, cycle between the ocean and the seafloor. Iron is also an important nutrient that controls how much productivity occurs in the surface ocean, which has important implications for fisheries. Ocean margin sediments may be an important source of iron to the Arctic Ocean. A key part of the project will focus on the changing iron content of Arctic rivers. The project leader will design educational activities to train students at Kent State University in planning oceanographic field work and using elemental data to study different ocean processes. The project will also provide outreach and education opportunities for Alaskan students and will support graduate and undergraduate students. The team will determine the distribution of reactive Fe within shelf sediments, the controls on active Fe remobilization, and links between Fe cycling and other nutrients, toxic trace metals, and economically important metals. The proposed research includes an expedition to the region to collect water column, sediment, and potential ferromanganese crust samples across four land to slope transects. Paired porewater and sediment geochemical results will be used to determine the modern exchange of Fe and other elements across the sediment water interface. Longer sediment cores will be used for paleoceanographic reconstructions of past changes in iron cycling. Education plans for the project will integrate research efforts and take advantage of the proposed oceanographic expedition and surrounding activities to engage with Alaskan middle school students, develop new skills-based curriculum for undergraduate and graduate students at Kent State University, and train students in seagoing and laboratory research techniques. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.