June 16, 2024

Ice Shelf Completely Disintegrates in East Antarctica

January 9, 2022
March 23, 2022
At the start of March 2022, the drifting shelf fed by the Glenzer and Conger glaciers was still intact. This image set (above), obtained by the Operational Land Imager (OLI) on Landsat 8, shows the rack before and after it broke down.
” The entire rack collapsed in simply around 2 weeks,” said Christopher Shuman, a University of Maryland, Baltimore County, glaciologist based at NASAs Goddard Space Flight. The icy residues of both glacial shelf ice and adjacent sea ice distributed from the waters around Bowman Island within weeks.
February 22– March 21, 2022
The development of the collapse shows up in the image series above. Images were acquired with the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASAs Terra and Aqua satellites.
The first image shows the ice shelf floating on the Mawson Sea on February 22, 2022, prior to the collapse. Quick ice– a type of sea ice that becomes “attached” to the edges of ice icebergs, shelves, and coastlines– is also part of the mix.
The significant loss of ice indicated the rack disconnected from Bowman Island. (Note that some sea ice stayed attached to the island.).
” Without being supported by a land anchor, the ice rack was destabilized and primed to collapse,” stated Jonathan Wille, a postdoctoral researcher at the Université Grenoble Alpes.
According to Wille, a climatic river on March 15 appears to have set off the shelfs final collapse. The weather system– which caused temperatures in eastern Antarctica to skyrocket 40 degrees Celsius above typical– likewise improved ocean swells and amplified winds near the vulnerable shelf. This most likely caused the ice in front of Conger Glacier to disintegrate and rapidly disperse.
The third MODIS image above shows the area on March 16 after the last collapse. The event spawned Iceberg C-38, which at the time determined about 415 square kilometers (160 square miles). The last image in the series shows the collapsed shelf ice and fast ice as it dispersed in the sea on March 21.
The loss of an ice shelf is problematic because it can indirectly contribute to sea level rise. “Ice racks are essentially the security band holding up the rest of the Antarctic Ice Sheet,” Walker said.
By Antarctic requirements, the ice shelf and glaciers that it held back are relatively small, so the effects from the collapse are expected to be very little. Scientists are more concerned about the area of the collapse.
” All of the previous collapses have actually taken place in West Antarctica, not East Antarctica, which until just recently has been considered reasonably steady,” Walker stated. “This is something like a gown rehearsal for what we could get out of other, more enormous ice shelves if they continue to melt and destabilize. Well truly be past the turnaround point in terms of slowing sea level rise.”.
NASA Earth Observatory images by Lauren Dauphin, using Landsat data from the U.S. Geological Survey and MODIS information from NASA EOSDIS LANCE and GIBS/Worldview.

The shelfs disintegration in March 2022 has reshaped a landscape where seaside glacial ice was once believed to be steady.
It is fairly typical for ice shelves in Antarctica to generate icebergs. It is less common for an ice shelf to totally break down. In March 2022, an ice rack in East Antarctica did both. The collapse has improved a part of the Antarctic landscape where coastal glacial ice was when believed to be steady.

In March 2022, an ice rack in East Antarctica did both. The icy residues of both glacial rack ice and adjacent sea ice dispersed from the waters around Bowman Island within weeks. Quick ice– a type of sea ice that becomes “secured” to the edges of ice shelves, icebergs, and coastlines– is also part of the mix. The final image in the series shows the fallen apart rack ice and fast ice as it dispersed in the sea on March 21.
“Ice shelves are essentially the security band holding up the rest of the Antarctic Ice Sheet,” Walker stated.