The largest iceberg globally is drifting and poses a potential threat to a small island in the South Atlantic, which could have consequences for the local wildlife, scientists cautioned this week.

Referred to as A23a, this massive iceberg spans 1,400 square miles and was anchored to the ocean floor near Antarctica for 37 years after it broke off from the Filchner Ice Shelf in 1986.

It resumed its movement last year and is now heading toward South Georgia Island, a small landmass predominantly home to penguins and seals.

Is There a New Development with the Iceberg?

As of April 2024, the iceberg had been trapped in a swirling water column near the South Orkney Islands, according to Andrew Meijers from the British Antarctic Survey. “It has recently detached from this current and is moving northeast with the Antarctic circumpolar current – on a route that could bring it dangerously close to South Georgia Island,” he explained.

Is the Iceberg a Sudden Threat to South Georgia Island?

“Sudden isn’t quite the right term for something we’ve been monitoring for nearly 40 years and that is currently drifting at about half a mile per hour,” Meijers communicated via email to YSL News on Tuesday. “However, its recent trajectory indicates that it is entering an ocean current jet – akin to an atmospheric jet stream – that is likely to lead it toward the island in the coming weeks.”

When Could It Reach the Island?

The iceberg is anticipated to approach the island in approximately 2 to 4 weeks, although this timeline may vary based on the current’s fluctuations and its precise course, Meijers noted. It could follow the current around the island’s continental shelf without grounding — similar to a large iceberg that recently did so — or it might become grounded in the shallower waters of the continental shelf, akin to an incident in 2004.

“It is nearly impossible to predict which scenario might happen, or whether the iceberg will fracture before that occurs,” he added.

Icebergs and South Georgia Island: A Dangerous Combination

Icebergs regularly pose a risk to the British territory of South Georgia Island due to its location in the Southern Hemisphere’s equivalent of “Iceberg Alley.” (This should not be confused with the “Iceberg Alley” in the Northern Hemisphere, found near Labrador and Newfoundland in Canada.)

Antarctica is surrounded by a strong counterclockwise current, as per the National Science Foundation. “Countless icebergs drift in this current around the continent until they near the Antarctic Peninsula, which extends toward Chile.

“In the Scotia Sea, situated between Chile and Antarctica, these icebergs are pushed northward where they begin to melt. Researchers designate this area as Iceberg Alley,” said the NSF.

Are Humans or Wildlife at Risk?

The seal and penguin populations on South Georgia Island might be affected if the iceberg grounds itself nearby, Meijers indicated. “This could hinder their access to feeding grounds and require adult animals to exert more energy to navigate around it. Consequently, this may reduce the food returned to pups and chicks on the island, ultimately increasing mortality rates.

“This situation occurred previously in 2004, although it remains uncertain if this iceberg will ground or not; later examples have shown it might maneuver around the island.”

As for human impacts, “Although the iceberg is quite large, Southern Ocean shipping operators can easily avoid it, as they are well aware of the risks posed by icebergs — and the location of A23a,” he explained. “However, as it breaks apart, the smaller ice chunks become much harder to monitor. Conversations with fishing operators indicate that prior large icebergs have rendered certain areas temporarily off-limits for fishing due to the proliferation of smaller, often more hazardous, iceberg remnants.”