Floating River Ice Channels Correspond to Sections of Thawing Riverbed Permafrost

Frontiers Earth Science, July 6

The ice resting on top of unfrozen river water – known as “floating” or “serpentine” ice – tends to form in the deeper sections of river channels with thawed riverbed sediment. Conversely, when river water freezes all the way down to the river bottom, the ice stretches out and covers across a large area, forming “bedfast” ice. For river channels such as the Lena River Delta of Russia, the largest in the Arctic, the consistent presence of floating serpentine ice suggests that unfrozen permafrost lies beneath. Thinning river ice and rising river water temperatures can affect the stability of permafrost beneath these riverbeds, with consequences extending into erosion, sediment movement, ice jams and related flooding, and damage to local infrastructure.