Iceberg A23a

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A23a's course mapped by the NASA Earth Observatory[1]

A23a is a large tabular iceberg which calved from the Filchner–Ronne Ice Shelf in 1986. It was then stuck on the sea bed for many years but then started moving in 2020. Its area is about 3,900 square kilometres (1,500 sq mi), which made it one of the largest icebergs in the world until it was temporarily surpassed in size by A76.[2][3]

In November 2023, A23a was tracked moving past the northern tip of the Antarctic Peninsula and headed toward the Southern Ocean.[4] On 1 December 2023, the iceberg was intercepted by the polar research ship RRS Sir David Attenborough, off the tip of the Antarctic Peninsula.[5] At 10 knots, it took the ship several hours to sail along two sides of the iceberg.[5] The iceberg is expected to release a significant quantity of mineral dust as it melts and so the ship took water samples around its perimeter.[5]

On 14 January 2024, dramatic archways caused by wave action on A23a were documented by a drone operated by Eyos Expeditions videographer Richard Sidey and expedition leader Ian Strachan. Their footage was published widely by the BBC and CNN.[6]

The base Druzhnaya I was placed on the iceberg, until it calved.[2] Subsequently, a rescue mission was started in 1987 and ultimately moved/renamed the base to Druzhnaya III.

References[edit]

  1. ^ Antarctic Iceberg Sails Away, NASA Earth Observatory, 28 November 2023
  2. ^ a b Jonathan Amos (24 November 2023), A23a: World's biggest iceberg on the move after 30 years, BBC
  3. ^ Largest iceberg (current), Guinness World Records, 28 October 2022
  4. ^ Stephen Smith (24 November 2023). "World's largest iceberg — 3 times the size of New York City — "on the move" for the first time in 37 years - CBS News". cbsnews.com. Retrieved 25 November 2023.
  5. ^ a b c Jonathan Amos (4 December 2023), Attenborough ship encounters mammoth iceberg, BBC
  6. ^ "A23a: Spectacular arches, caves as monster iceberg decays". 16 January 2024. Retrieved 22 January 2024.