Biggest iceberg spins in ocean trap

A23a, the world's largest iceberg, has been observed spinning in place just north of Antarctica instead of drifting with the Antarctic Circumpolar Current (ACC). This phenomenon is attributed to a Taylor Column, a rotating mass of water created by an underwater feature known as Pirie Bank. A23a, which is over twice the size of Greater London, has been trapped in this vortex since early April 2024, rotating anti-clockwise at about 15 degrees per day. Despite its edges crumbling, the iceberg remains largely intact, suspended above a depth of at least 1,000 meters of water.

Originally breaking free from the Antarctic coastline in 1986, A23a spent three decades as a static "ice island" before re-floating in 2020. Its current situation is unusual, as icebergs typically fragment and melt away. Scientists are intrigued by A23a's longevity and the dynamics of the ocean that allow it to remain in this state. The Taylor Column phenomenon, first described in the 1920s, illustrates how underwater topography can significantly influence ocean currents and biological activity. Understanding these dynamics is crucial for comprehending the broader implications for climate systems, as they affect the distribution of heat and nutrients in the ocean. Currently, only a quarter of the Earth's seafloor has been mapped, highlighting the need for further exploration and understanding of these underwater features.