Imagine standing by the sea and seeing a giant block of ice as big as several cities combined. That’s what iceberg A23a looks like. Broken off from Antarctica, the iceberg has floated north since 2020.
On March 1, the colossal iceberg ran aground 73 km from South Georgia, an island home to countless penguins and seals. People worried this iceberg would disrupt these animals’ ability to find food, but the island’s wildlife may no longer be in danger should the gigantic ice wall stay in place.
The iceberg is large enough that vessels would be able to avoid it. However, experts warn that when the iceberg starts breaking apart, the resulting smaller icebergs would be hazardous, restricting commercial fishing in some areas. Some scientists warn that freshwater from melting ice could affect krill (a small shrimp-like crustacean that penguins eat), forcing penguins to travel farther to feed.
On the bright side, researchers believe the iceberg carries large amounts of nutrients locked in its ice. As it melts, it will release these nutrients into the ocean. Tiny plants and animals in the water would get a boost and grow quickly, becoming food for bigger fish and, in turn, for penguins, seals, and even whales.
Icebergs are born when huge chunks of ice break off ice shelves in Antarctica. A23a broke off almost 40 years ago, which is a very long time for an iceberg to stay mostly in one piece. It is unclear how long the iceberg will remain stuck off the coast of South Georgia.
Even though this giant ice block appears dangerous, it also shows how nature finds ways to create life from something that seems cold and lifeless. By watching A23a, scientists learn how our changing planet affects the oceans, Antarctica, icebergs, and the local wildlife.