Coastal changes in the Arctic

The Arctic’s climate system is changing: air temperatures, major river discharges and open water season length have increased, and storm intensities and tracks are changing. Thirteen quantitative studies of the rates of coastline position change throughout the Arctic show that recently observed changes have not increased coastal erosion rates, which currently range between 0 and 2 m/yr when averaged for the arctic shelf seas. Current data is probably insufficient, both spatially and temporally, however, to capture change at decadal to sub-decadal time scales. In this context, we describe the current understanding of arctic coastal geomorphodynamics with an emphasis on erosional regimes of coasts with ice-rich sedimentary deposits in the Laptev, East Siberian and Beaufort seas, where local coastal erosion can reach 30 m/yr. We also examine coasts with lithified (rocky) substrates where geomorphodynamics are intensified by rapid glacial retreat. Coastlines of Svalbard, Greenland, and the Canadian Archipelago are less frequently studied than ice-rich continental coasts of North America and Siberia and studies often focus on coastal sections composed of unlithified material. As air temperature and sea ice duration and extent change, longer thaw and wave seasons will intensify coastal dynamics in the Arctic