Rising Air Temperatures Break Up Larsen B Sea Ice from Antarctic Peninsula

NASA Earth Observatory, 2 February 2022

Rising air temperatures and increasingly wet weather caused a large region of sea ice off the Antarctic Peninsula, that had persisted even through the summer since 2011, to break up completely during a few days in January. Strong winds and the formation of meltwater ponds on the surface from rains apparently contributed to this rapid fracture. These darker ponds readily absorb sunlight and erode the ice below them, weakening the overall structure and leaving it vulnerable to fracturing and collapse.

This sea ice had persisted in the region where the 3250 km2 Larsen B Ice Shelf existed until 2002, when it disintegrated and allowed several nearby glaciers to speed up their discharge of ice into the sea. Ice shelves act like a buttress holding back land glaciers, and under cooler conditions a new ice shelf might have formed from this persistent sea ice to again slow glacier discharge and related sea-level rise. Its break-up underscores theories of more rapid Antarctic ice loss, as it shows the difficulty of “growing back” a new ice shelf under current conditions of CO2 rise and associated rapid global warming, not only of the atmosphere but of Antarctica’s surrounding waters.