Hidden Groundwater Reservoirs in Antarctica May Increase Ice Loss

Science, 5 May 2022

This study provides the first direct evidence of a deep groundwater system below the surface of the Antarctic Ice Sheet. These hidden pockets of water reduce the friction between the ice sheet and underlying bedrock, accelerating the flow of ice into the ocean. This groundwater system can also dig pathways through the sediment below the ice sheet, creating downhill slopes for the ice to follow. Researchers located this deep reservoir filled with salt water underneath the Whillans Ice Stream in West Antarctica; it contains 10 times more water than that in the ice above. Ice streams – regions of fast-moving ice within an ice sheet – account for 90% of the ice that travels from the continent’s interior to the ocean; and it appears that the additional lubrication provided by such groundwater reservoirs has accelerated ice loss from the Whillans region. These reservoirs also contain salt water, which prevents or slows them from freezing regardless of the season. As global temperatures rise, these reservoirs may release even more groundwater and increase Antarctic ice sheet loss and related sea-level rise in a warming climate.