A68A was the sixth-largest iceberg on record when it broke off its ice shelf in July 2017. During the first two years of its life, the Weddell Sea near the Antarctic Peninsula was very cold and it stayed the same size. The European Space Agency called it a “mega iceberg.”
Researchers from the University of Leeds, the Centre for Polar Observation and Modelling, and the British Antarctic Survey looked at satellite images of the iceberg. They found that over the years, the iceberg got smaller as it broke apart and melted. In three and a half years, the iceberg is thought to have lost about 544 cubic kilometers of its ice. About a third of that was due to melting at the bottom.
A lot of fresh water and nutrients were released into the ocean by the iceberg over the course of three months while it was near South Georgia.
This big loss could have a big impact on the island’s ecosystem, a study says. One concern was that the iceberg could hit the seafloor near an island. However, it turns out that in December 2020, the closest the iceberg got was about 38.5 miles away from the island.
While A68A didn’t hit the seafloor, researchers say it’s possible that it will hit the floor in some of the shallower areas in the future. A grounded iceberg can also change the flow of the ocean, making it hard for the island’s penguins to feed in the sea, say researchers.
Study leader Anne Braakmann-Folg said in a statement that the berg released a “huge amount of melt water.” In an interview with CBS News, she said it’s too early to say what the specific effects of A68A will be, but that in general, cold freshwater from icebergs can “foster biological production.” There are also a lot of whales, fish, and Antarctic krill living in the waters around the islands, which the government says are a “key link” in the Southern Ocean food chain.
