Thwaites glacier (WAIS) melt

HBS Guy

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Abstract

Thwaites Glacier is the most rapidly changing outlet of the West Antarctic Ice Sheet and adds large uncertainty to 21st century sea-level rise predictions. Here, we present the first direct observations of ocean temperature, salinity, and oxygen beneath Thwaites Ice Shelf front, collected by an autonomous underwater vehicle. On the basis of these data, pathways and modification of water flowing into the cavity are identified. Deep water underneath the central ice shelf derives from a previously underestimated eastern branch of warm water entering the cavity from Pine Island Bay. Inflow of warm and outflow of melt-enriched waters are identified in two seafloor troughs to the north. Spatial property gradients highlight a previously unknown convergence zone in one trough, where different water masses meet and mix. Our observations show warm water impinging from all sides on pinning points critical to ice-shelf stability, a scenario that may lead to unpinning and retreat.
https://advances.sciencemag.org/content/7/15/eabd7254

Warm water is melting the ice the glacier is grounded in the sea—enough of the ice holding the glacier to the bedrock melts then the glacier will flow faster to the sea.

Whatever volcanic heat is under the WAIS melts enough of the base of the glacier on land to lubricate the sliding of the glacier—things could change fast with the melt of Thwaites glacier and consequent jump in sea levels—Thwaites glacier is HUGE and if it goes the adjacent Pine Island glacier will go too!
 

HBS Guy

Head Honcho 💉💉
Staff member
For illustration:


grounding-line.-Huybrechts-et-al-2009.-nature.jpg
As warm water reaches the ice sheet it melts the ice shelf and the grounding line moves inland. Eventually the ice shelf breaks off and the glacier moves faster into the sea—ice shelves act as breaks on glacier movement. In the WAIS the ground slopes down as the glacier front moves inland meaning more and more ice breaks off and floats away.
 
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