Thermal Denudation Landforms in Areas of the Ice Complex Occurrence in Northern and Central Yakutia

This paper presents a comprehensive overview of thermal denudation landforms in Central and Northern Yakutia. Thermal denudation is driven by the effects of air and water heat on ice-rich sediments and massive ground ice, located near the surface. The Ice Complex deposits are widespread within the region under consideration. Their degradation on the surface of the Yedoma uplands is mainly associated with frontal thermal denudation and includes thaw subsidence, which lead to the formation of a series of successive stages of thermokarst landforms. Thaw subsidence on the Yedoma surface typically amounts to several centimeters per year. Lateral thermal denudation is common on the Yedoma slopes and along the riverbanks, seacoasts and lake shores, where ice-rich deposits are exposed. The main landforms associated with lateral thermal denudation are thermocirques and thermoterraces. Their growth rates reach 3–15 m/yr, and in paragenesis with thermal abrasion or fluvial lateral thermal erosion, it can exceed 22 m/yr. Active processes of thermal denudation lead to the mobilization of material preserved in permafrost. As global warming will continue permafrost degradation will most likely accelerate.