Arctic Coastline Erosion: Novel Experimental Avenues Help Understand Its Response To A Changing Climate

Abstract

Permafrost coastlines represent a large portion of the world’s coastal area and these areas have become increasingly vulnerable owing to the changing climate and its strong dynamics observed over the past decades (Irrgang et al., 2022). The predominant mechanism of coastal erosion in these areas has been identified through several observational studies as thermomechanical erosion—a joint removal of sediment through the melting of interstitial ice (thermal energy) and abrasion from incoming waves (mechanical energy). Longer summer seasons where -due to a much lower ice cover- waves can more freely propagate towards Arctic coastlines have exacerbated coastal erosion (Overeem et al., 2011) and which is projected to increase inline with Arctic warming (Nielsen et al., 2022). Erosional effects have long been a subject of the coastal engineering community, however, the combined effect of wave attack on shorelines, in combination with thermomechanical processes has largely been overlooked. The implications of Arctic coastline erosion are plenty: local communities face relocations of whole settlements, loss of valuable property or cultural heritage while acceleration in thaw causes a much higher influx of environmental contaminants and nutrients into the Arctic Ocean. It is hence crucial to engage this pressing challenge with long established and novel methods originating from the coastal engineering community. This work provides an overview over novel avenues that are useful for a better understanding of the processes and interactions of ocean waves and Arctic coastlines. It also presents some of the recent erosional observations from a cold room flume and micro CT measurements.