Material Fluxes through Small River Systems on the Alaskan North Slope
Dr. Shawn Gallaher | United States Naval Academy
Changes in Arctic regional climate can affect the timing, duration, and intensity of the Arctic spring-summer thaw cycle and therefore alter the biogeochemistry of mountain and tundra river systems as they flow toward the coastal system of the Arctic Ocean. In this project, the U. S. Naval Academy Polar Science and Technology Program will lead a joint field team of Service Academy faculty and students through a comprehensive study of representative small, Alaskan North Slope seasonal rivers in order to identify material sources from degrading permafrost and quantify fluxes of carbon, metals, stable isotopes, and heat. This will allow for a better understanding of the current and future role these systems have on water column structure, ice conditions, circulation, material (biogeochemical) cycling/fate, and transport on the U.S. portion of the Alaskan Beaufort shelf/slope.
This project will use an integrated approach involving Service Academy faculty and students to develop low-cost solutions to observing small river systems using unmanned aerial vehicles (UAVs), autonomous surface vehicles (ASVs), fixed monitoring stations, in situ data collection, and discrete sample collection for biogeochemical analysis coupled with remote sensing. This will result in high-resolution, 3-dimensional (3-D) surveys of basin morphology and vegetation cover (aerial surveys and 3-D Lidar), and in situ CDOM fluorometry and absorbance, scattering, and reflectance, turbidity, and pH. The investigators will also conduct a biogeochemical analysis of discrete samples of water, sediments, particulate matter, and soils for major ions, bulk elements, organic carbon, trace elements, and stable isotopes collected throughout the river basin from the North Slope headwaters to the coastal Arctic Ocean mouth during the spring-to-late-summer period over multiple years.
Project results will continue the time series initiated by earlier scientist in the Toolik Lake region in characterizing the material sources and their transport through small river systems as permafrost continues to decay on the Alaskan North Slope. These results will attempt to show that changes in Arctic regional climate can affect the timing, duration, and intensity of the Arctic spring-summer thaw cycles and therefore alter the biogeochemical composition of small rivers along the U.S. Alaskan North Slope. This data will also enhance understanding of the changing Arctic environment as its strategic importance increases along with its potential as a future battlespace. Additionally, participation of the U. S. Service Academy Midshipmen and Cadets in this research effort will build lasting relationships and professionally develop these young men and women as they move toward their futures as U.S. military leaders.