Researchers have released the first aerial images of a massive iceberg breaking off the Antarctic ice shelf in January. The Greater London-sized piece of ice, labeled A81, finally broke away from Antarctica’s Brant Ice Shelf ten years after the first cracks appeared and joined other pieces of glacier floating in the Weddell Sea. This is the second giant cleavage and calving recorded in two years, although a natural process in this frozen landscape, it can still harm the environment.

“An iceberg of this size would have a major impact on ocean ecosystems that support the rich diversity of marine wildlife in this part of Antarctica,” explains ecologist Geraint Tarling. “These effects can be both positive and negative.”

Dynamic aerial images taken by the British Antarctic Survey (BAS) show how large this block of ice is, which even from above seems like an endless sheet. But what we can see is only a fraction of the iceberg’s mass, most of its mass extending hundreds of meters deep.

BAS moved the entire research station to avoid being dragged onto the currently floating ice sheet. In 2016, Halli’s research station was moved 23 kilometers after high-precision GPS devices and satellite data showed that the chasm across the Brant Ice Shelf was widening.

The A81 now flies 150 kilometers from where it was once attached to the polar continent. Icebergs of this size not only pose a threat to human activities, but can also significantly affect local ecology.

“When an iceberg melts, it releases many nutrients that can support the growth of microscopic plants, such as phytoplankton at the bottom of ocean food webs,” says Tarling of BAS.

“The downside is that melting itself on such a large scale dumps a lot of fresh water into the ocean, which lowers salinity and makes the water suitable for the many phytoplankton and zooplankton that feed them. These effects can then cascade the food web for fish, birds, seals and whales. “

The BAS team continues to closely monitor the A81, along with other icebergs in the area, including the A76a, to be aware of the risks it may pose. The A81 is expected to follow the Antarctic Coastal Current, but the A76a heads for some islands. With an area of ​​3,200 square kilometers, A76a is twice the size of the A81, currently the largest floating iceberg on Earth.

“It looks like the A76a may be heading west of South Georgia,” said Mark Belchier, Director of Fisheries and Environment for the South Georgia Government. “Our main concern at this point is the potential risk to ships operating in the area as the iceberg begins to break up and break up into smaller pieces of ice.”

“If A76a continues on its trajectory towards Shag Rocks, cutting off the shallow seafloor there could have disastrous consequences for diverse biodiverse seafloor communities, including breeding grounds for valuable fish stocks,” adds Tarling.