12/31/2023 0 Comments Antarctica iceberg breaking off 2017![]() ![]() Geological Survey and MODIS data from NASA EOSDIS LANCE and GIBS/Worldview. NASA Earth Observatory images by Lauren Dauphin, using Landsat data from the U.S. Then we’ll really be past the turnaround point in terms of slowing sea level rise.” “This is something like a dress rehearsal for what we could expect from other, more massive ice shelves if they continue to melt and destabilize. “All of the previous collapses have taken place in West Antarctica, not East Antarctica, which until recently has been thought of as relatively stable,” Walker said. Scientists are more concerned about the location of the collapse. “And that is what raises sea levels.”īy Antarctic standards, the ice shelf and glaciers that it held back are relatively small, so the impacts from the collapse are expected to be minimal. When they collapse, the ice behind them can more quickly flow into the ocean. “Ice shelves are essentially the ‘safety band’ holding up the rest of the Antarctic Ice Sheet,” Walker said. The loss of an ice shelf is problematic because it can indirectly contribute to sea level rise. The final image in the series shows the crumbled shelf ice and fast ice as it dispersed in the sea on March 21. The event spawned Iceberg C-38, which at the time measured about 415 square kilometers (160 square miles). The third MODIS image above shows the area on March 16 after the final collapse. This likely caused the ice in front of Conger Glacier to break apart and quickly disperse. The weather system-which caused temperatures in eastern Antarctica to soar 40 degrees Celsius above normal-also enhanced ocean swells and amplified winds near the vulnerable shelf. “Without being supported by a land anchor, the ice shelf was destabilized and primed to collapse,” said Jonathan Wille, a postdoctoral researcher at the Université Grenoble Alpes.Īccording to Wille, an atmospheric river on March 15 appears to have triggered the shelf’s final collapse. (Note that some sea ice remained attached to the island.) The substantial loss of ice meant the shelf disconnected from Bowman Island. A few pieces broke off, such that C-37 measured about 81 square kilometers on March 12 when MODIS acquired the second image in the series. Named C-37, the berg initially measured about 144 square kilometers (56 square miles). According to Catherine Walker of the Woods Hole Oceanographic Institution, the shelf was losing ice at an average rate of about 1 square kilometer per day through the natural process of iceberg calving.īut in early March 2022, the shelf in front of the Glenzer Glacier calved a substantial iceberg. For two years prior to this image, the shelf was already in a state of decline. Fast ice-a type of sea ice that becomes “fastened” to the edges of ice shelves, coastlines, and icebergs-is also part of the mix. The first image shows the ice shelf floating on the Mawson Sea on February 22, 2022, prior to the collapse. Images were acquired with the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra and Aqua satellites. The progression of the collapse is visible in the image series above. “All of this took less than a month,” Shuman said. The icy remnants of both glacial shelf ice and adjacent sea ice dispersed from the waters around Bowman Island within weeks. “The whole shelf collapsed in just around two weeks,” said Christopher Shuman, a University of Maryland, Baltimore County, glaciologist based at NASA’s Goddard Space Flight Center. This image pair (above), acquired by the Operational Land Imager (OLI) on Landsat 8, shows the shelf before and after it disintegrated. By the middle of the month, it had fallen apart. At the start of March 2022, the floating shelf fed by the Glenzer and Conger glaciers was still intact. The collapse has reshaped a part of the Antarctic landscape where coastal glacial ice was once thought to be stable. In March 2022, an ice shelf in East Antarctica did both. It is less common for an ice shelf to completely disintegrate. It is relatively common for ice shelves in Antarctica to spawn icebergs. ![]()
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