Disintegration of A68a Iceberg Released 152 Billion Tons of Freshwater into Ocean
A68 was the 6the largest iceberg on record when it broke free from Larsen-C in July 2017 and scientists have been keeping an eye on it ever since
Dubbed A68a, the iceberg that was once the largest on the globe was a part of the Larsen-C ice shelf, and has recently released 152 billion tons of freshwater close to the sub-Antarctic island of South Georgia. A study, which had been observing the dissolution of the iceberg from space, said that the added amount of water has potentially impacted the region’s ecosystem.
The iceberg initially drifted around the Weddell Sea close to Antarctica before heading toward the Drake Passage between southern South America and the northern shores of Antarctica. When it approached the southern Atlantic island of South Georgia in December 2020, researchers were concerned that it would disrupt wildlife in the isolated region, however, the iceberg broke down into pieces before it could unsettle the ecosystem.
The recent study, published in ScienceDirect, indicated that the massive iceberg had a big impact on the local environment. Over a three-month span between 2020 and 2021, A68a melted quickly as it reached warmer waters in the Drake Passage. Initially, the researchers feared that the bottom of the iceberg will run aground on the seafloor, consequently, blocking currents and predator foraging routes.
Anne Braakmann-Folgmann, a glaciologist from the University of Leeds in the UK and the study’s lead author, said;
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…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.
A group of five satellites was employed to track the position, area, thickness, and volume change of A68a iceberg since it calved. At its peak, the iceberg melted at a rate of 23 feet per month.
While it didn’t block the currents to the islands, it did release a massive amount of freshwater that likely impacted the South Georgia ecosystem. The magnitude of the increased sea level is still to be determined, but authors of the study speculate that the A68a’s route through the Drake Passage could help scientists study more about future icebergs and how they impact the polar oceans.
If so, the valuable information could help a lot considering climate change is likely to cause more collapses in Antarctica, leading to more icebergs breaking off from ice shelves. Regardless, the addition of 152 billion tons of freshwater to the oceans cannot be good news to the coastal areas across the world that are already facing the threat of floods and sea-level rise.
Via: The Verge