A City-Size Iceberg Is Moving Out of Antarctic Waters


It’s massive. It’s icy. And it’s moving.

It’s an iceberg named A23a. Wait, that’s what they’re calling it? Come on, we can do better.

It’s Superberg!

For more than 100 years, no iceberg has been more famous than the one that sank the Titanic and abruptly ended Rose and Jack’s fictional romance. But that was before a mammoth berg started meandering northward from Antarctica.

Where is it headed? How did this happen? What does it all mean? You have questions, we have answers.

The iceberg initially tore off Antarctica — a process known as calving — in 1986. But it did not get far and soon became stuck in the Weddell Sea, south of South America.

That changed in 2020, when it started moving again. It is now chugging along and is just about to pass the tip of the Antarctic Peninsula and leave Antarctic waters.

Scientists say it is currently the world’s biggest iceberg at 1,500 square miles. That’s about five times the land area of New York City. It’s also about 1,300 feet thick, roughly equivalent to the height of the Empire State Building.

Most likely the berg will head to a part of the Southern Ocean known as Iceberg Alley, where bergs like to congregate. So don’t expect it to cruise by Copacabana Beach or the Côte d’Azur.

Despite what Hollywood has taught you, A23a will not be tearing through populated areas, nor will it turn sentient because of an ancient curse and seek revenge for humanity’s mistreatment of polar bears.

Instead, it will eventually go the way of the snows of yesteryear or the ice in your gin and tonic and break down into smaller pieces and melt. But, because of its huge size, it will take years to disappear into the sea. (A previous iceberg, declared the world’s largest at the time, took about two decades to disintegrate.)

When ice starts leaving Antarctica, it’s hard not to think about climate change and be concerned about a fleet of massive bergs bent on destruction advancing into the Atlantic in years to come.

“The climate is changing, and it is impacting how ice shelves melt,” said Indrani Das, an associate research professor at the Lamont-Doherty Earth Observatory at Columbia University and a glaciologist, an expert on snow and ice. “Ice shelves are losing mass because the ocean is warming. Calving is a natural process, but that natural calving could be enhanced by climate.”

But because this particular iceberg calved back in 1986, she said, it was going to break free in any case. And that isn’t automatically a bad thing.

“An ice shelf losing its mass is a natural process,” she said. “If it doesn’t calve, it’s going to keep growing. The ice shelf has to be balanced.”

Well, maybe not. There are risks to Superberg’s journey.

“Icebergs are dangerous if they come to a shipping lane,” Dr. Das said. “It could isolate a colony of penguins. We will know as we follow its trajectory.”

But, she added: “I like to see the brighter sides of things. As icebergs melt away, they give fresh water and nutrients to the ocean. Icebergs are beautiful, and they’re interesting.”

As long as you’re not Jack Dawson or an isolated penguin.



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