South Pole: The world’s largest iceberg is moving again
Iceberg A23a has been on Earth for decades. But now it’s on the move again: it may finally end in a graveyard of icebergs.
© Porolando/Getty Images/iStock (details)
Compared to this iceberg, A23a is the size of a larger island, and its journey could take longer.
In 1986, a huge piece broke off the Filchner Ice Shelf in Antarctica. With an area of about 4,000 square kilometres, it was soon considered the largest iceberg on Earth and named A23a: its area exceeds the size of the island of Majorca or twice the size of the Saarland, just for a common comparison. However, the journey ended quickly, because the giant’s powerful hull got stuck at the bottom of the Weddell Sea. But at the end of 2023, the speed of the iceberg will increase after observing the first small movements of the giant, which weighs a trillion tons and is up to 400 meters thick, since 2020. This is what the British Broadcasting Corporation (BBC) reported..
Driven by strong winds and currents, A23a passed the northern tip of the Antarctic Peninsula in November 2023, and continues to move north, where it will soon encounter the Antarctic Circumpolar Current. It is also called the iceberg track because most of the icebergs coming from the Weddell Sea land there and drift away with it. As a rule, this route takes icebergs to South Georgia Island in the South Atlantic Ocean, where they drift back into shallow water and eventually break up or die. Because of the frequency with which smaller or larger formations end here, the area is also called the “Iceberg Graveyard.”
An Iceberg A-23a broke off from the Filchner ice shelf in September 1986 and fell into the southern Weddell Sea in November 1991. Nearly three decades later it began moving north. Maybe you’re tired of smaller and smaller ones #A68 The iceberg gets all the attention. @Copernicus @ESA_EO pic.twitter.com/gnFEKxYF55
– Polarview (@polarview) September 9, 2020
Because of A23a’s massive dimensions, biologists fear the impact on wildlife in South Georgia, where millions of seabirds nest and many seals and whales give birth: the iceberg could block the path to feeding grounds. However, similar fears about the A-68 iceberg, which was also very large, proved to be unfounded: it also met its end in this particular graveyard, but without causing any major problems for the animal world: due to the high tide. And the tides, the winds and the waves. It quickly broke up into smaller units, some of which drifted across the island.
The melting icebergs also release nutrients and minerals that were trapped in the ice and release much-needed fertilizer in some areas: this then leads to growth spurts of plankton, which is at the beginning of the food chain.
It is unclear why A23a started moving again after years of silence. However, there is no more precise information about this: after more than three decades, it may have lost enough mass and volume that it could lose its grip on the sea floor. With the help of satellites, his fate will be followed from space. At the time of its construction in 1986, the ice surface housed a Soviet polar station, as the BBC reported. Moscow sent an expedition to recover materials from Drozhnaya-1, fearing the station would soon sink into the sea.
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