Arctic coasts have different structures depending on the region. In Alaska, Canada or Siberia, for example, they are particularly rich in ground ice with permafrost bluffs that range in height up to 40 metres. In Greenland, Svalbard and the Canadian Archipelago, on the other hand, the coasts usually contain little to no ground ice but, instead, large volumes of coarse, glacially derived sediment, or even solid rock. These regional geomorphological differences influence how other environmental variables affect coasts. For example, if air and water temperatures change, it affects the entire coastal system. Ice-rich permafrost bluffs, for example, some of which are up to 80 percent ice, are quite resilient to mechanical wave action. However, when they thaw due to increased air and water temperatures, they become particularly vulnerable to destruction by waves, which manifests itself in rapid coastal erosion.
Arctic coasts are thus particularly sensitive to climate: Global warming is causing large areas of permafrost to thaw, ground ice to melt and land surfaces to collapse. This in turn affects the availability and quality of water, the growth of plants, and increases soil stripping (erosion) and coastal flooding. In addition, sea surface temperatures rise in most parts of the Arctic, which can extend the sea ice-free period. Coasts are then exposed to strong waves for much longer, especially during the stormy fall season.
Arctic shoreline changes