Strong currents took hold of a huge Antarctic iceberg that is on a collision course with South Georgia Island, causing it to shift direction and lose a major chunk of mass, a scientist tracking its journey said.
As the iceberg, called A68a, approached the western shelf edge of the South Atlantic island this week, it encountered strong currents, causing it to pivot nearly 180 degrees, said Geraint Tarling, a biological oceanographer with the British Antarctic Survey.
“You can almost imagine it as a handbrake turn for the iceberg because the currents were so strong,” Dr Tarling said.
That is when the berg appeared to clip the shelf edge, causing a large piece to break apart. That new piece is an iceberg in its own right and already has a name, A68d.
For weeks, scientists have been watching the massive iceberg, last measured at 4,200 square kilometres, as it rode a fast-track current towards the island.
Researchers feared that, as the berg closed in on the wildlife-rich island, it could grind into the seabed, disrupting underwater ecosystems. They were also worried that the berg might block penguins from making their way into the sea for food.
As of Friday, the original A68a iceberg was about 50 kilometres from the island’s west coast.
It appeared, however, to be heading south-east towards another current that would probably carry it away from the shelf edge before sweeping it back around towards the island’s eastern shelf.
That means the berg could still cause an environmental disaster for local wildlife, but along the island’s eastern coast rather than the south-west.
“All of those things can still happen. Nothing has changed in that regard,” Dr Tarling said.
The new smaller berg, A68d, is moving farther away from the original one.
Scientists had predicted some chunks could break away from A68a as it approached the island, and more breakage is possible.