It broke off from the Brunt Ice Shelf, from the Chasm-1 rift, last January and currently occupies the second position in the list of large floating ice masses on the planet. It is iceberg A-81 and in the last two months it has traveled about 150 kilometers in a westerly direction, in the waters of the Antarctic Ocean, dragged by the marine currents of the Weddell Sea.
The British Antarctic Survey (BAS, a British scientific entity attached to the Natural Environment Research Council) has released (March 13) the first aerial images (from airplanes) of this great iceberg, captured in recent weeks at various points along its contour. Until now, the images of this large fragment of floating ice had been captured from satellites.
The teams that have flown over the A-81 are part of the BAS Halley Research Station, which is relatively close to this detached ice. "The images show the dynamic nature of the iceberg, surrounded by smaller icebergs that also broke off," explains this scientific institution on its blog on the Internet.
The A-81 has an area of 1,550 km², that is, an area equivalent to three times that of the entire territory of Andorra or 15 times the area of Barcelona (101.35 km²). For British experts and media, the A-81 has an area equivalent to the size of Greater London, while seen from the United States, this vast iceberg is comparable to three times Manhattan.
The BAS explains that Brunt is "one of the most closely guarded ice shelves on the planet", in part because it is home to the BAS Halley Research Station, relocated in 2016 precisely to avoid damage from cracking ice. "The monitoring carried out by the BAS glaciologists shows that the area of the research station is currently not significantly affected by the A-81 calving. This fragmentation, "is a natural process along the Antarctic coast, and the A-81 is the second large iceberg in the region in two years."
Oliver Marsh, a BAS glaciologist, explained that experts from this scientific institution have been monitoring the Brunt Ice Shelf and the chasms formed through it for more than a decade. "Since glaciologists first observed the enlargement of Chasm-1 in 2012, BAS science and operations teams have been anticipating the calving event. High-precision GPS instruments, as well as satellite data, have been used to monitor the widening of the chasm and, in 2016, BAS took the precaution of moving the Halley Research Station inland to protect it.”
