We will all be learning together about what appears to be a rapid deterioration of the Amundsen Bay Embayment in West Antarctica.
The embayment holds four feet of sea level rise occurring after the disintegration of the Thwaites Eastern Ice Shelf and the Thwaites Western Ice Shelf, which is more stable than the eastern half. The shelf includes three glaciers, Pine Island Glacier, Thwaites Glacier, and Crossen Glacier.
On January 23, 2023, satellite imagery captured the beginning of the collapse of the ice above the flow of a subglacial channel that runs between Pine Island and Thwaites glaciers.
The reason for the collapse is extreme heat at the base between the two glaciers. The heat is generated by the glaciers grinding over the bedrock, which causes friction heating, and by geothermal sources that create a warm undertow melting the ice from the bottom up.
It has been determined that a rift system underlies this region and is “expressed by topography from the Byrd Subglacial Basin.“ The basin is the lowest point on the planet's continental plates at 1.87 miles below the ocean.
Science Direct Journal:
...we prefer the hypothesis that Marie Byrd Land volcanoes are thermally-supported by warmer upper mantle. The presence of such inferred warm upper mantle also suggests regionally elevated geothermal heat flux in this sector of the West Antarctic Rift System and consequently the potential for enhanced meltwater production beneath parts of Thwaites Glacier itself. Our new crustal thickness estimates and geothermal heat flux inferences in the Thwaites Glacier region are significant both for studies of the structure of the broader West Antarctic Rift System and for assessments of geological influences on West Antarctic Ice Sheet dynamics and glacial isostatic adjustment models.
The FLOR, Feeding Laterally Oriented Route (FLOR), is likely a 2-way system that maintains the Pine Island Bay Gyre. Van Steenbergen noted that when the sea ice in front of Pine Island Glacier collapses, even more heat will find its way to the underbelly of Thwaites glacier.
Yesterday, satellite imagery caught the sea ice imploding in front of Pine Island Glacier. Today the FLOR is compromised.
This morning, Kris Van Steenbergen posted the below tweet.
The sea ice implosion:
