Patterns in vegetation composition, surface height and thaw depth in polygon mires in the Yakutian Arctic (NE Siberia): a microtopographical characterisation of the active layer

Mapping of two low‐centred ice‐wedge polygons in the Yakutian tundra (NE Siberia) along a regular grid with 1‐m spacing revealed large spatial variability in thaw depths and strong correlation with relief, water and vegetation. Average thaw depths in polygon ridges (23 cm and 31 cm) were smaller than in depressions (33 cm and 40 cm, respectively). The greatest thaw depths, however, were also found in the ridges and probably result from thermal erosion by water flow.