An iceberg about the size of Delaware heading towards the subantarctic island of South Georgia has worried experts that it could block wildlife from food sources and threaten the island’s ecosystem.
The iceberg, known as the A68a, was about 400 kilometers, or about 250 miles, off the coast of the British island territory of South Georgia on Wednesday, the British Antarctic Survey said.
The iceberg could run aground near the island and be a few weeks off the island’s coast, said Andrew Fleming, a remote sensing official in charge of the investigation.
The iceberg broke away from the Antarctic Peninsula in 2017 and is approximately 100 miles long and 30 miles wide. The trajectory of the iceberg could change and move away from the island, as it is in the strongest ocean current where the waters are not impeded by the continents. This means that the iceberg could easily pass in front of the island, it all depends on the path that nature takes.
It is unpredictable what could happen if the iceberg washed up near South Georgia, said Mr. Jackson, an explorer glaciologist with the National Geographic Society. Such episodes are not uncommon, but they are usually given more attention when they pose a threat to people and wildlife, she said.
There is a chance that if A68a fails, it could disrupt part of South Georgia’s ecosystem, affecting some of the areas and paths that animals, such as seals and penguins, use to hunt and gather wildlife. the food.
“Essentially, seals and penguins are born on land and then commute into the ocean to stock up and come back with food to feed their young,” Dr. Jackson said. “The iceberg could disrupt that, and the seals and penguins might not be able to get and deliver food to their land puppies and chicks, which could trigger widespread famine.
Douglas R. MacAyeal, a geophysical science professor at the University of Chicago who has studied the behavior of large icebergs, compared A68a to another large iceberg, the B-15A.
In the 2000s, the B-15A struck parts of Ross Island in the Ross Sea as well as other icebergs surrounding it, disrupting the island’s penguin colonies. Some colonies have spent years without hatching chicks. The disturbance has led some penguins to breed with those from different colonies.
“This led to a genetic advantage of exchanging genetic material from different normally isolated cohorts,” Dr MacAyeal said in an email. “In my opinion, if A68a encountered the island itself or the shoals around it, it would be spectacular for a few days but would not lead to an ecosystem disaster.”
Some experts predict that the A68a will eventually shatter into large pieces as a result of strong currents.
“The Southern Ocean around South Georgia is a completely wild place with strong currents and a sea swell that will ‘flex’ the iceberg above the grounding point, causing it to stress and fracture a bit. like a ship, ”said Dr MacAyeal.
If the iceberg breaks near the coast of the island, it could displace large amounts of seawater “which can inundate coastal communities,” Dr Jackson said.
This type of danger is a problem that experts have had to contend with, as climate change has caused ice to melt and ice systems to rupture at significant rates.
“I doubt that, given the increasing rate of ice melt around the world, this will be the last time we will see this,” Dr Jackson said. “I wouldn’t be surprised in the years to come if we continue to see larger icebergs posing greater dangers to communities of people and wildlife.”