CIÊNCIA
Maior icebergue do mundo a rodopiar no oceano
August 6, 2024 - O maior icebergue do mundo, conhecido por A23a, está capturado num vórtice oceânico a norte da Antártida que o pode impedir de derreter durante anos.
A23a broke away from the Antarctic coast in 1986. Almost immediately, it grounded on the seabed and was stuck for more than three decades. In 2020, it refloated.
In early April this year, A23a stepped into the Antarctic Circumpolar Current, but instead of heading towards warmer waters, it became trapped in a type of vortex known as a Taylor Column, a massive rotating cylinder of water.
A Taylor Column forms when a current that meets an obstruction on the sea floor separates into two distinct flows, generating a full-depth mass of rotating water between them.
In this instance, the obstruction is a 100km-wide bump on the ocean bottom known as Pirie Bank. The vortex sits on top of the bank, and for now A23a is its prisoner, BBC reports.
A23a, which has an area of 3,600 sq km – twice the size of Greater London – could be stuck for years, scientists say.