Wave-driven shoreline changes along the Beaufort and Chukchi coasts

Abstract:

The physical vulnerability of Arctic coastlines is directly linked to the presence of nearshore sea ice, which acts as a protective barrier against ocean waves. The observed increase in the length of the open water season coincides with an expected rise in storm frequency, especially in the autumn. Additionally, deep-water observations and modeling studies reveal a clear trend of increasing surface wave activity in the Beaufort and Chukchi seas, related to prolonged retreat of seasonal offshore sea ice. The associated potential for flooding and erosion at the coasts is complicated by the sediment composition, some which may be more vulnerable to rising temperatures (permafrost sediments at bluffs) or increasing waves (mobile sediments at barrier islands and spits). Using an equilibrium shoreline framework, we investigate decadal trends in shoreline retreat and assess the relative roles of waves and ocean temperature in causing shoreline retreat. We apply a recently collected set of coastal wave observations and a model hindcast climatology to understand how shorelines are moving in response to both the changes in the forcing from offshore and changes in the natural protection from the shorefast ice.

Funded by the National Science Foundation and the Office of Naval Research.