The Earth’s largest iceberg is slowly breaking apart on a crash course with South Georgia, threatening fragile wildlife colonies and revealing hidden dynamics of the Southern Ocean.
Looming over the waves like a drifting fortress of ice, the massive slab has become the focus of mounting scientific and maritime attention.
According to Live Science, the colossal structure has begun shedding thousands of fragments into nearby waters, sparking concern among researchers and navigators alike.
Its steady approach toward a remote British territory raises new questions about iceberg behavior, penguin survival routes, and long-term changes in polar ecosystems, without yet revealing the full extent of what lies ahead.
The Megaberg A23a Spins Into Trouble
The colossal A23a, known as the “megaberg”, is not only the largest iceberg currently afloat but also one of the oldest. Born in 1986 when it calved from Antarctica’s Filchner Ice Shelf, it remained trapped on the seafloor for decades, then later caught in an ocean vortex, spinning in place.
After finally breaking free in December 2024, A23a entered the Drake Passage — nicknamed the “iceberg graveyard” — and began drifting north toward South Georgia. The island, a remote British overseas territory, now finds itself directly in the iceberg’s path.
As of mid-May, the iceberg was just 173 miles (280 km) from the island.
Satellite Images Show the Giant Breaking Apart
NASA’s Aqua satellite recently captured a stunning transformation. The northern edge of A23a is crumbling, releasing a blizzard of icy debris.
Thousands of iceberg pieces litter the ocean surface near the main berg, creating a scene reminiscent of a dark starry night – NASA representatives wrote.
Many measure at least a kilometer across and would pose a risk to ships.
The megaberg once covered 3,900 square kilometers but now measures about 3,500 km² — roughly the size of Cornwall. Its towering ice walls reach 1,312 feet (400 meters), taller than London’s Shard.
Some slabs of ice are breaking off like floating cities, with the largest fragment — A23c — drifting southward, measuring 130 km².
Penguins, Seals and the Island Under Pressure
South Georgia is home to millions of seals and penguins, including King penguins and elephant and fur seals. When icebergs like A38 grounded here in 2004, they blocked access to feeding areas, leaving dead chicks and pups along the shores.
Now, fears are growing that A23a could repeat this disaster.
Icebergs are inherently dangerous. I would be extraordinarily happy if it just completely missed us – Said Captain Simon Wallace aboard the Pharos, a government patrol ship.
Scientists and sailors around the globe are watching A23a’s movements daily, tracking it through satellite imagery.
Iceberg Alley: A Rising Threat for Fishers
According to Andrew Newman, from the fishing company Argos Froyanes, the iceberg’s fragments are everywhere:
It is in bits from the size of several Wembley stadiums down to pieces the size of your desk. Those pieces basically cover the island.
With searchlights on all night, sailors must navigate through unpredictable debris.
It can come from nowhere – Said Captain Wallace.
In 2023, iceberg A76 drifted dangerously close as well.
Chunks of it were tipping up, so they looked like great ice towers, an ice city on the horizon – recalls Mark Belchier, a marine ecologist advising the South Georgia government.
These events are more frequent. As Belchier notes, “South Georgia sits in iceberg alley” — and while both fisheries and wildlife are resilient, the scale of the threat is growing.
Iceberg Water: A Chemical Fingerprint From the Past
Before melting away, A23a offered a unique scientific gift. In 2023, the Sir David Attenborough research vessel approached the berg, and scientists took rare water samples just 400 meters from its icy walls.
I saw a massive wall of ice way higher than me, as far as I could see… Chunks were falling off — it was quite magnificent – said Laura Taylor, a PhD researcher.
Her analysis could help decode how iceberg meltwater impacts the carbon cycle in the Southern Ocean. The melt isn’t just pure water — it contains nutrients, chemicals, and phytoplankton, tiny organisms that can lock away carbon dioxide as they sink.
