The Arctic Coastal Dynamics Database: A New Classification Scheme and Statistics on Arctic Permafrost Coastlines

Abstract

Arctic permafrost coasts are sensitive to changing climate. The lengthening open water season and the increasing open water area are likely to induce greater erosion and threaten community and industry infrastructure as well as dramatically change nutrient pathways in the near-shore zone. The shallow, mediterranean Arctic Ocean is likely to be strongly affected by changes in currently poorly observed arctic coastal dynamics. We present a geomorphological classification scheme for the arctic coast, with 101,447 km of coastline in 1,315 segments. The average rate of erosion for the arctic coast is 0.5 m year −1 with high local and regional variability. Highest rates are observed in the Laptev, East Siberian, and Beaufort Seas. Strong spatial variability in associated database bluff height, ground carbon and ice content, and coastline movement highlights the need to estimate the relative importance of shifting coastal fluxes to the Arctic Ocean at multiple spatial scales.

Transformation of terrestrial organic matter along thermokarst-affected permafrost coasts in the Arctic

“…The island is underlain by continuous permafrost and characterized by polygonal tundra, valleys, and a rolling landscape that reaches a maximum elevation of 183 m above sea level (de Krom, 1990;Rampton, 1982). Permafrost on Qikiqtaruk is extremely ice-rich with mean ice volumes ranging between 30 and 60 vol%, and up to values N 90 vol%, when underlain by massive ground ice beds (Couture and Pollard, 2015;Fritz et al, 2015;Lantuit et al, 2012a). The active layer depth generally ranges between 40 and 60 cm in summer (Burn and Zhang, 2009;Kokelj et al, 2002).…”

“…Thermokarst in upland, inland, sub-Arctic, and High Arctic permafrost regions, was intensively studied focusing on the lability of permafrost carbon, greenhouse gas emissions, release of nutrients (e.g., nitrogen, phosphorus, sulfur), and impacts on aquatic systems Cassidy et al, 2016;Frey et al, 2007;Turetsky et al, 2007). However, only a few studies are available on coastal thermokarst, which is ubiquitous along the ice-rich permafrost coasts in the Arctic, and on the fate of OM within the coastal environment (Lantuit et al, 2012a;Lantuit and Pollard, 2008;Pelletier and Medioli, 2014).…”

Observing Muostakh disappear: permafrost thaw subsidence and erosion of a ground-ice-rich island in response to arctic summer warming and sea ice reduction

“…Muostakh Island in the southern Laptev Sea is a prominent example (Are, 1988a, b;Romanovskii et al, 2000;Grigoriev et al, 2009) of thousands of kilometres of unstable unlithified coastline along arctic shelf seas (Lantuit et al, 2011a;Overduin et al, 2014). Along this coast, cliffs border marshy coastal tundra lowlands and islands that are underlain by continuous permafrost and composed of continental late Pleistocene ice-rich permafrost sequences called Ice Complex deposits (Schirrmeister et al, 2013).…”

Expansion of vegetated coastal ecosystems in the future Arctic

“…As a consequence of ice melting on land, the Arctic Ocean is receiving increasing amounts of ice melt water, causing a rapid freshening of the Arctic Ocean (Dai et al, 2009;McPhee et al, 2009). Ice loss and an extended open water period are leading to significant coastal erosion problems, particularly acute along the Siberian and Beaufort coasts (Lantuit et al, 2012). Increased freshwater discharge also contributes, along with resuspension of eroded coastal sediments (Lantuit et al, 2012), to increase turbidity in the coastal zone, which has been forecasted to reduce light penetration and primary production along the Siberian shelf, receiving the discharge of some of the world's largest rivers (Slagstad et al, 2011).…”