Thermo-erosion along the Yedoma Coast of the Buor Khaya Peninsula, Laptev Sea, East Siberia

Coastal erosion in continuous permafrost regions with high ground ice content is affected by subsidence and mass transport due to thawing of ground ice. Using sites along the western coast of the Buor Khaya Peninsula, we introduce an index for thermo-erosion based on the change in position of the upper and lower edges of the coastal bluff through time. Field surveys of thermo-terraces and an Alas were compared with historical elevations and coastlines. Using survey TINs and photogrammetry-derived DEMs, coastal position change, volumetric land loss and the Normalized Difference Thermo-erosion Index (NDTI) was calculated. Coastline erosion varied from 0.4 to 3.3 m a-1 over the 36 year period from 1974 to 2010, resulting in volumetric erosion of 7 000 to 67 000 m3 a-1 per km of coastline. NDTI values show coastline erosion dominated by thermo-abrasive to thermo-denudative processes.