Research Seminar, Caroline Cooper: Arctic Deltas: Modeling the effects of sea ice on arctic delta morphology

The Arctic has experienced rapid increases in temperatures in recent decades, shifting cryosphere terrestrial and ocean processes. This has implications for arctic deltas which are the meeting place for land-sea interactions. Seasonal sea ice coverage has been present in the arctic ocean for the development of modern deltas like the Colville River Delta which has led to unique fluvial sediment pathways and complex geomorphologies when compared to those in temperate regions. Little long-term morphologic modeling has been done on arctic deltas which has left a gap in our understanding of sea ice controls on delta formation. To address this, a long-term morphologic and hydrodynamic model was constructed in Delft3D to simulate the temporal evolution of the Colville River Delta, the largest delta on the Alaskan Arctic Coast. Model simulations begin at 6 ka, when Holocene transgression ended, resulting in the development of modern deltas. Simulations are in 2D, from the delta apex down to the shelf break, and include the dominant arctic seasonal conditions that drive coastal morphology: freeze-up, break-up/freshet, and open-water. The model uses the novel approach of a floating structure (barges) on the water surface to mimic the lid-like effect of nearshore landfast sea ice on hydrodynamics. This model should help address how certain features of arctic deltas formed and provide insight on future morphologic processes of arctic deltas as this environment begins to warm.

Passcode is UNCEMES