In the frigid expanse of the Antarctic seas, expedition leader Ian Strachan faced a moment of awe as his ship approached a colossal presence on the horizon. Shrouded in snow and fog, the sight was initially obscured, but as the clouds lifted, a vast, almost abstract white line stretched out before them.
\"Then the clouds lifted and we could see this expansive – almost abstract – white line that extended each way across the horizon,\" Strachan recounted. As the vessel drew nearer on Sunday, the true majesty of the iceberg revealed itself: massive gaping crevasses and stunning blue arches etched into its edge.
The iceberg, named A23a, is a behemoth nearly 4,000 square kilometers in size—over twice the area of Greater London—and up to 400 meters thick in places. After three decades anchored to the Antarctic ocean floor since breaking off the coast in 1986, A23a is now embarking on what could be its final journey north.
Waves up to four meters high relentlessly batter the iceberg's walls, smashing off small chunks and causing some of the intricate arches to collapse. Strachan likened the experience to sailing along an endless sheet of music, where \"all the cracks and arches were different notes as the song played.\"
Containing an estimated one trillion tonnes of fresh water, A23a is expected to melt into the ocean as it drifts northward. Currently navigating between Elephant Island and the South Orkney Islands, the iceberg is taking a similar path to previous giants like A68 and A76 through the infamous \"iceberg alley\" in the Weddell Sea.
Andrew Fleming of the British Antarctic Survey noted that satellite images in 2020 indicated the iceberg was beginning to wobble, leading to its eventual release late last year. While the role of climate change in A23a's movement remains uncertain, Fleming emphasized that the formation and movement of such icebergs are natural processes, with one or two large icebergs breaking off each year.
However, Fleming also highlighted that these icebergs are part of a "huge system that is changing dramatically." As A23a moves into the Southern Ocean, warmer waters and increasing wave activity will accelerate its demise. There is a slight concern that if A23a heads towards the island of South Georgia in the South Atlantic Ocean, it could disrupt the local wildlife, including penguins and seals, by blocking their foraging paths.
While some icebergs have traveled far enough north to be seen from the Brazilian coast, the inevitable fate of A23a is to melt away in warmer waters. \"Ultimately, they're doomed,\" Fleming concluded, underscoring the transient nature of these majestic ice giants.
Reference(s):
World's biggest iceberg 'battered' by waves as it heads north
cgtn.com
