Colossal iceberg nearly the size of London nears a British island after traveling 1,400 miles; here’s how it could benefit marine life and the environment

A gigantic iceberg nearly the size of London that broke off from Antarctica and has been traveling for three years across the Southern Ocean is now approaching a British Island in the South Atlantic. Known as Iceberg A-81, NASA on Tuesday, October 27, posted the image of the massive block of ice as the ‘image of the day.’

The satellite image captured by NASA’s Terra satellite on October 20, 2026, shows the iceberg lingering close to South Georgia, an island that has trapped other giant icebergs in the past.

Iceberg A-81 parted ways from its icy home in Antarctica’s Brunt Ice Shelf and began its voyage in January 2023. Then it was approximately 600 square miles of snow that did not immediately head into the open Atlantic.

Iceberg A-81 has been floating for three years

For over three years, it moved through the Weddell Sea, where ocean currents took it along the Antarctic coastline, largely driven by the Weddell Gyre. It is a massive clockwise circulation of ocean water that dictates how icebergs travel in the southern hemisphere.

It then moved north, and by late October 2026, it reached warm waters near the remote island of South Georgia, the largest of nine islands that make up the South Georgia and South Sandwich Islands in the South Atlantic Ocean, after traveling 1,400 miles north-northwest of its origin.


As per US National Ice Center, by mid-October 2026, A81’s size was reduced to approximately 517 miles (or 1,340 km²), according to the US National Ice Center.

The iceberg started to slow

Now, as the colossal iceberg approached the British territory, it began to slow. Before it was photographed on October 20, “it appeared to be bumping along the edge of the island’s underwater shelf,” NASA said, quoting Jan Lieser of Australia’s Bureau of Meteorology and Christopher Shuman of the University of Maryland.

A-81, although traveling for three years, the process started much earlier. A major fracture known as Chasm 1 remained relatively stable for approximately 35 years, within the Brunt Ice Shelf, and around 2012, fractures began expanding.

By 2019, the rift had grown to the point that scientists expected a large section of the ice shelf to break away. But it didn't. Then, in January 2023, it finally broke away and produced Iceberg A-81. This process of breaking a big chunk of ice and traveling occurs naturally, and scientists call it calving.

South Georgia has a history of stopping icebergs

South Georgia is a go-to place for icebergs, as in the past, it slowed and even stopped icebergs before. In 2025, Iceberg A-23A, the largest one ever recorded, was grounded on the shelf and later broke apart into smaller pieces after its long journey from Antarctica. It was about 1,400 to 1,500 square miles at its peak.

In 2021, a fracture known as the North Rift produced Iceberg A-74, which was around 490 square miles. Then, three years later, another major fracture called the Halloween Crack produced Iceberg A-83, spanning around 145 square miles.

Brunt Ice Shelf is also important for another reason; it is home to the British Antarctic Survey’s Halley Research Station, a major research station for Earth’s atmosphere, climate, and space environment since the 1950s.

Impact on marine life

Moving Antarctic icebergs as they drift through the ocean can create hotspots of marine life. A 2007 study published in Science, led by Ken Smith of the Monterey Bay Aquarium Research Institute (MBARI), found that these floating islands of ice are having a major impact on the ecology and chemistry of the ocean around them, which serves as “hotspots” for ocean life.

As they move into warm waters, they melt and release trapped nutrients into the sea, which support the growth of phytoplankton, a major food for krill and other marine animals.

“The Southern Ocean lacks a major source for terrestrial material due to the absence of major rivers. The icebergs constitute a moving estuary, distributing terrestrial derived nutrients that are typically supplied by rivers in other areas of the oceans,” geochemist Timothy Shaw of the University of South Carolina said to MBARI.

“One important consequence of the increased biological productivity is that free-floating icebergs can serve as a route for carbon dioxide drawdown and sequestration of particulate carbon as it sinks into the deep sea,” said MBARI oceanographer Ken Smith in the statement.

“While the melting of Antarctic ice shelves is contributing to rising sea levels and other climate change dynamics in complex ways, this additional role of removing carbon from the atmosphere may have implications for global climate models that need to be further studied,” Smith explained.

The researchers estimated that icebergs could increase biological productivity across nearly 40% of the Weddell Sea, although they noted that more research was needed to understand their overall ecological and climate impacts.