Picture of the huge iceberg A-81 recorded by NASAs Terra satellite on January 25, 2022
After breaking from the Brunt Ice Shelf, Iceberg A-81 and other pieces of ice drift south with the Weddell Gyre.
On January 22, 2023, the British Antarctic Survey reported that a new iceberg had actually broken from Antarcticas Brunt Ice Shelf. In the days following the long-awaited break, satellites have captured numerous brand-new pictures of the behemoth berg as it drifts south.
Two days after the iceberg initially broke off, NASAs Terra satellite acquired a broad view of the area, which experts at the U.S. National Ice Center (USNIC) utilized to verify the break. Later on, on January 25, 2023, the Operational Land Imager (OLI) on Landsat 8 obtained these detailed views.
The first image shows the iceberg wandering in the Weddell Sea. The berg, which USNIC named Iceberg A-81, measured about 1550 square kilometers (600 square miles)– about two times the location covered by New York City. The main berg is surrounded by smaller sized icebergs, sea ice, and a composite mix of ice types covered in snow called mélange.
January 25, 2022.
The second image, likewise obtained January 25 with OLI on Landsat 8, shows a detailed view of the smaller keystone-shaped iceberg in between A-81 and the new front of the Brunt Ice Shelf. This is the part of the rack where a rift, which has been growing in spurts since at least the 1970s, lastly covered the entire rack and broke the drifting glacial ice apart. In the rifts last advance, it reached an intricate part of the ice rack and bifurcated, cutting out the keystone-shaped iceberg. It measures simply several kilometers– tiny compared to A-81, which determines 52 kilometers on its longest axis.
According to Christopher Shuman, a University of Maryland, Baltimore County, glaciologist based at NASAs Goddard Space Flight Center, satellite images show that the front of the Brunt Ice Shelf is now more than 20 kilometers back from its position in early 1973. The British Antarctic Surveys (BAS) Halley Research Station, which was moved further inland in 2016, is now about 15 kilometers from the new front of the ice rack. BAS reported that the station was unaffected by the recent break.
At the time of these images, Iceberg A-81 and other pieces of ice were drifting southward with the clockwise movement of the Weddell Gyre, although it stays to be seen where they will go from here. A previous berg that broke from the ice shelf in February 2021 (Iceberg A-74) followed the gyre. Its pieces now wander more than 500 kilometers far from Brunt near the Ronne-Filchner Ice Shelf.
NASA Earth Observatory images by Lauren Dauphin, using Landsat data from the U.S. Geological Survey. Caption by Kathryn Hansen with image interpretation from Christopher Shuman (NASA/UMBC).
The primary berg is surrounded by smaller icebergs, sea ice, and a composite mix of ice types covered in snow called mélange.
The 2nd image, likewise got January 25 with OLI on Landsat 8, reveals a detailed view of the smaller keystone-shaped iceberg in between A-81 and the new front of the Brunt Ice Shelf. At the time of these images, Iceberg A-81 and other pieces of ice were wandering southward with the clockwise motion of the Weddell Gyre, although it remains to be seen where they will go from here. A previous berg that broke from the ice shelf in February 2021 (Iceberg A-74) followed the vortex.