Satellite Images Chronicle the Total Collapse of a New York-Sized Ice Shelf in Antarctica
All it took for the Conger-Glenzer ice shelf in Antarctica to collapse was just a few days which, in the world of science, is an unusual phenomenon. Scientists then used satellite imagery to chronicle and observe the “evolution” and eventual demise of the New York-sized ice shelf spread out over 1,200 square kilometers in East Antarctica. Conger-Glenzer’s rapid disintegration in 2022 rang alarm bells among Australian and international researchers considering they had predicted the Antarctic region where it was situated to be far more stable, per a report by the Australian Broadcasting Corporation. Interestingly, the scientists had stumbled on the Conger-Glenzer disintegration during an observation campaign of a neighboring ice shelf in the eastern region.
Ten ice shelves under observation had disintegrated since the mid-1990s. These ice shelves were located in West Antarctica and the Antarctic Peninsula. However, the rapid demise of the Conger-Glenzer ice shelf occurred in four distinct phases during an analysis period of 25 years using satellite imagery and other data. Between 1997 to 2000, fragments of the ice shelf began to disintegrate separating Conger-Glenzer from Shackleton Ice Shelf. The surface area of the ice shelf was reduced by about 10% by the next decade as gradual thinning continued until 2019. In light of an extreme weather event, the Conger-Glenzer witnessed accelerated disintegration in March 2022.
"In its weakened state, an unprecedented atmospheric river made landfall nearby in March 2022, bringing with it strong winds and large ocean swells," said Dr. Catherine Walker, from the United States-based Woods Hole Oceanographic Institution. He is also the lead author of a new report studying the collapse of the Conger-Glenzer with two members of the Australian Antarctic Program Partnership, per the paper published in the journal Natural Geoscience. Dr. Walker revealed that the storm directly did not lead to the collapse but paced it up even before the storm peaked. Moreover, she was concerned about the increasing unpredictability of ice shelf collapses and changes observed in East Antarctica.
"Long considered more stable than the West Antarctic Ice Sheet, this event added an exclamation point to the accelerating narrative of unexpected changes being observed in East Antarctica," she noted. Dr. Walker said that the Conger-Glenzer demise was due to ocean-induced thinning and structural weakening instead of the anticipated ice melt due to global warming. As a result, this phenomenon sparked concerns about the other locations of ice shelves that could potentially collapse in the future while researchers study the early warning indicators.
Ice shelves are pivotal to maintaining the Antarctic ecosystem as they surround large of the coastline protecting the continental ice sheet. According to the report, these ice shelves act like “buttresses” that protect about 58 meters of potential sea level rise if the ice sheet melts completely. Therefore, Dr, Walker pointed out, “When ice shelves thin, retreat, fracture, and crevasse, their buttressing capabilities are diminished.” With the cracks and crevasses, the ice shelf then allows quantities of the ice sheet to flow out into the ocean, thus, contributing to sea level rise significantly. Even though the Conger-Glenzer is a fraction of the ice shelves in Antarctica, it could potentially cause a disbalance in the sea level rise, further affecting other parts of the world.