The world's largest iceberg seems to have been stranded near the unremote British island

The world's largest iceberg appears to have stranded millions of penguins and seals along the remote British island, which may threaten local wildlife, but also provides opportunities for research on this rare “giant giant”.

The huge ice cube, known as the A23a, is about the size of Rhode Island and weighs nearly 10,000 tons – a few months ago heading towards Georgia, South Georgia, has reportedly raised concerns that it could collide with the island and destroy the balance of local wildlife.

The British Antarctic Survey (BAS) said Tuesday that the iceberg apparently hit the continental shelf around southern Georgia, about 73 kilometers from the island itself.

Whether the A23A will get stuck for a long time (and the effects it may have on local wildlife) is still in the air.

“It will be interesting to see what will happen now,” BAS oceanographer Andrew Meijers said Tuesday.

The sub-anti-Antarctic island of South Georgia is a British overseas territory located north of Antarctica and about 1,850 kilometers east of South America. It supports a small, non-permanent population of scientists and researchers but is known for its abundant wildlife, including 5 million seals for four different species and 65 million birds in 30 different species. These include the wandering albatross, the largest flying bird in the world, and several types of penguins.

One of the researchers’ concerns is that icebergs can block wildlife from normal pathways from feeding sites, forcing them to go longer distances and bring less food to young people.

But Meijers notes that icebergs store important micronutrients that they release when they melt and can also stir up nutrients in deep water, benefiting local ecosystems.

If this “tall ice” stimulates ocean productivity, he said, it could “promote populations of local predators such as seals and penguins.”

A 40-year journey

Running is the latest development in the dramatic 40 years of life of this ice giant.

The A23A was separated from the Filchner ice shelf in Antarctica in 1986, but was still trapped on the seabed of the Wadel Sea for the next three decades.

After breaking in 2020 and riding the current northward along the tip of the Antarctic Peninsula, the A23A hit another obstacle: an ocean vortex called the Taylor column that captured it in place for several months.

Since squirting from the vortex, the A23A has been slowly spinning towards southern Georgia.

Georgia and South Sandwich Islands Government says In the statement In January, it is “closely monitoring” the progress of the A23A, and when transportation and fishing may be affected, “the impact on wildlife may be local and transient.”

Satellite images show that the iceberg approached the continental shelf in late February, and then it appeared to freeze when it was stranded, with no major movement visible since March 1.

What might happen

The A23A may start moving again as it is more susceptible to storms near the island that may shake or damage it, Donavan Tremblay, an ICE expert for the Canadian Coast Guard, told CBC News.

But “it could be staying for a while too,” he said.

Despite relatively few icebergs on this scale, this is not the first time that Megaberg has threatened South Georgians. In 2020, an iceberg called the A68A (formerly the largest in the world and the sixth largest record in history) was separated on the island after hitting a shelf.

A 2022 study found that A68A releases 152 Gironton freshwater and nutrients into the oceans in southern Georgia. This has changed the salt concentrations in surface water enough that more than two months after the iceberg melted, according to a separate 2023 study.

Scientists are still investigating the impact on local ecosystems, including on whales, seals and plankton levels – A23A is helping.

One focus Meijers highlighted is how the release of nutrients can help produce phytoplankton's flowers and potentially improve the ocean's ability to capture more carbon dioxide from the atmosphere.

Other scientists want to know what’s going on under A23a, which will give huge scars on the seabed and potentially trigger a water slide, said Alex Normandeau, a research scientist with the Canadian Geological Survey.

“What are the consequences for marine geology?” he asked. “Because it affects the habitat where the iceberg is grounded, but it also affects sedimentary suspension and underwater processes.”

Icebergs separate from the Antarctic ice sheet and drifting northward is a regular part of the Antarctic ice life cycle, but Mayers said the data suggests that ice shelves have been losing more mass over the past 20 years, a development scientists attribute climate change to climate change.

“These are urgent and active areas of research in BAS and elsewhere,” he said.