Scientists have completed the monitoring of the breakaway Antarctic "megaberg" designated A68a, researchers from the University of Leeds in the UK have reported, determining in their study that the 5,719-square-kilometre berg released some 152 billion tonnes of freshwater in mere months before melting away completely.
The researchers followed the megaberg using five satellites, monitoring its size, thickness, and estimated volume. According to them, the iceberg was melting at a rate of 7 metres per month at its peak.
A68a released the billions of tonnes of freshwater it consisted of in just three months as it floated near the island of South Georgia in the Atlantic Ocean some 1,400 kilometres away from the Falkland Islands. And now scientists are wondering whether the melting of such an enormous iceberg, the sixth-largest in recorded history of satellite monitoring, has had any effect on the local ecosystem.
"This is a huge amount of meltwater, and the next thing we want to learn is whether it had a positive or negative impact on the ecosystem around South Georgia", glaciologist from the University of Leeds, Anne Braakmann-Folgmann, said.
An iceberg can damage local ecosystems in various ways – from scraping the seabed, which A68a apparently didn't, to blocking regular wildlife routes, and releasing huge amounts of freshwater and nutrients into the salty ocean water. The iceberg could have also hit the island itself, home to various species of marine animals such as penguins, but A68a melted before it could do so.
Studying the impact of A68a on the local marine flora and fauna might prove to be useful in the future, the scientists said.
"Because A68a took a common route across the Drake Passage, we hope to learn more about icebergs taking a similar trajectory and how they influence the polar oceans", Anne Braakmann-Folgmann said.
A68a broke away from Antarctica in July 2017 and travelled some 4,000 kilometres before melting down completely in March 2021. Several smaller bergs broke away from it in the process as well.