SGER: Using 4He/3He thermochronometry to quantify the rate and timing of Canadian Shield fjord incision
Jason Briner Principal Investigator
MetadataShow full item record
Using 4He/3He thermochronometry to quantify the rate and timing of Canadian Shield<br/>fjord incision<br/><br/>Intellectual Merit - The relationship between topographic relief development and climate<br/>change has emerged as a critical topic in earth science. Linking relief generation to climate<br/>change, e.g. the onset of the Quaternary ice age, relies on a quantitative understanding of the<br/>pattern and timing of glacial erosion. Although alpine glacial erosion in active orogenic belts has<br/>been the focus of recent research, fjorded continental margins, arguably the sites of the most<br/>intense glacial incision, in which fjords >1 km deep have been inserted since the ice ages began,<br/>have yet to be examined in detail. The rates and spatial patterns of fjord insertion, and the<br/>feedbacks between ice sheet dynamics, topography, and glacial erosional processes are important<br/>components of Quaternary climate and landscape change. The aim of this research is to quantify<br/>the temporal and spatial evolution of a fjord inserted into the northern Canadian Shield by the<br/>Laurentide Ice Sheet. The research team will apply a novel tool, 4He/3He thermochronometry, to<br/>quantify the rate and pattern of formation of Clyde Inlet, a fjord on Baffin Island typical of<br/>dozens of other fjords rimming the Canadian Shield, and representative of fjords around both<br/>Greenland and Norway.<br/>Samples for 4He/3He thermochronometry will document the thermal history of Clyde Inlet,<br/>which in turn will constrain the long-term incision history of the fjord. Both fjord cross-section<br/>and fjord long-profile sample sets will be collected, which will potentially quantify both vertical<br/>exhumation and headward propagation rates of the fjord. The results of the proposed research<br/>represent a critical step toward the team's longer-term goal of improving the understanding of<br/>the feedbacks between ice sheet dynamics and landscape evolution. The erosional history of the<br/>fjord is the key observational constraint for numerical ice sheet simulations aimed at solving the<br/>complex feedbacks between topography and ice sheet behavior. The erosional history of fjords<br/>exerts a significant control on ice sheet thickness and configuration, the locations of major ice<br/>streams and their onset zones, and the overall stability and configuration of marine-based<br/>margins of ice sheets.<br/>Broader Impacts - This research will train one early-career scientist (Briner) and will expose<br/>graduate and undergraduate students at the Universities of Buffalo and Colorado to novel<br/>applications and exciting earth science problems. Research activities under this award will be<br/>made accessible to indigenous peoples by translating the goals and eventual results into Inuktitut,<br/>making posters that describe the research, and by offering public lectures in Iqaluit, the capital of<br/>Nunavut, and at Clyde River, our proposed field base. The team will continue their tradition of<br/>working with the people of Clyde River, including guides, the Hunter's and Trapper's<br/>Association and high school students. In addition, Anderson will continue his efforts to educate<br/>the broader public about glacial landscape evolution through involvement in ranger training<br/>programs at US National Parks in which glaciers have played significant roles in sculpting the<br/>landscape, and in generation of simulations that can serve both as educational tools in K-12 and<br/>college classrooms, and as dynamic content in National Park displays.