Back A23a BE Iceberg A-23a Catalan A-23 A German A23a Spanish Jäämägi A23a ET ای۲۳ای (کوه یخی) FA A23a French A23a Latvian/Lettish A23a Dutch A23a Romanian

A23a

A23a's course mapped by the NASA Earth Observatory[1]
Satellite images in 2024
Map
Interactive map of A23a as of 23 January 2025 (map data)

A23a is a large tabular iceberg which calved from the Filchner–Ronne Ice Shelf in 1986. It was stuck on the sea bed for many years but then started moving in 2020. As of January 2025, its area is about 3,500 square kilometres (1,400 sq mi), which makes it the current largest iceberg in the world.[2][3][4]

The base Druzhnaya I, which was originally established on the Filchner–Ronne Ice Shelf, was situated on the iceberg when it calved.[3] Subsequently, a rescue mission was started in 1987 and ultimately moved/renamed the base to Druzhnaya III.[5]

In November 2023, A23a was tracked moving past the northern tip of the Antarctic Peninsula and heading towards the Southern Ocean.[6] On 1 December 2023, the iceberg was intercepted by the polar research ship RRS Sir David Attenborough, off the tip of the Antarctic Peninsula.[7] At 10 knots, it took the ship several hours to sail along two sides of the iceberg.[7] A23a is expected to release a significant quantity of mineral dust as it melts, so the ship took water samples around its perimeter.[7]

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.[8] In early April 2024, the iceberg entered the Antarctic Circumpolar Current but stayed in place as it was trapped in a Taylor column—as confirmed in August 2024—over the Pirie Bank seamount near the South Orkney Islands about 375 miles from the Antarctic Peninsula, turning counterclockwise by around 15 degrees every day.[9][10][11] In December 2024, the British Antarctic Survey (BAS) reported that the iceberg had exited the Taylor column and was now beginning to drift further north through the Southern Ocean.[12]

The BAS expects A23a to follow the Antarctic Circumpolar Current towards the island of South Georgia in the southern Atlantic Ocean, where it will eventually encounter warmer water and break up into smaller icebergs.[13][2] As of 23 January 2025, A23a is 173 miles (278 km) away from South Georgia and still on its way towards the island, potentially threatening the penguin and seal populations by blocking their access to feeding grounds.[2]

  1. ^ Cite error: The named reference NEO was invoked but never defined (see the help page).
  2. ^ a b c Rannard, Georgina; Rivault, Erwan (23 January 2025). "Giant iceberg on crash course with island, putting penguins and seals in danger". BBC News. Retrieved 23 January 2025.
  3. ^ a b Cite error: The named reference BBC was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference GWR was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference NYT was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference cbs was invoked but never defined (see the help page).
  7. ^ a b c Cite error: The named reference BBC2 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference BBC3 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference NYT2 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference BBC4 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference NPR was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference BBC5 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference BAS was invoked but never defined (see the help page).

A23a

Dodaje.pl - Ogłoszenia lokalne