EVOLUTION OF ARCTIC CONTINENTAL SHELVES: MODELLING MORPHODYNAMIC FEEDBACKS TO CLIMATE-DRIVEN INCREASES IN SEA STATES

• Main Author: Malito, John
• Other Authors: Eidam, Emily F, Rodriguez, Antonio, McKee, Brent, Sebastian, Antonia
• Format: Master Thesis
• Language: English
• Published: University of North Carolina at Chapel Hill Graduate School 2021
• Subjects: Coastal oceanography; Sediment transport modelling; Marine geology; Arctic shelf evolution; Coastal morphodynamics; Arctic; Beaufort Shelf; Sea ice
• Online Access: https://doi.org/10.17615/14sq-wj55; https://cdr.lib.unc.edu/downloads/2r36v726m?file=thumbnail; https://cdr.lib.unc.edu/downloads/2r36v726m

Arctic continental shelves, including the Alaskan Beaufort Shelf (ABS), are experiencing declines in sea ice coverage and duration which are leading to increasingly energetic sea states and coastal erosion. A Delft3D sediment transport model was developed to test how present-day and projected future waves impact shelf evolution, and how shelf geometry modifies propagation of waves toward the coast. Wave-induced sediment transport and morphologic adjustment were enhanced on a relatively steep ABS shelf section (slope 0.0008) under increased projected waves. Redistribution of sediments from the inner shelf to the middle shelf led to attenuation of projected waves as the shelf evolved, creating a regulatory feedback loop. In contrast, effective wave attenuation across a relatively flat shelf section (slope 0.0003) limited cross-shelf transport and morphologic change. Our findings suggest that morphodynamic feedbacks to the growing Arctic wave climate depend on shelf geometry and can impact future coastal erosion. Master of Science