Back in January, I wrote about A-68a – the world’s largest iceberg – that was on a collision course with South Georgia Island, an island about 950 miles from the Antarctic Peninsula. The iceberg initially measured more than 2300 square miles (6000 square kilometers)! Read more background here.
About 6 weeks later, there is some good news! According to NASA’s Earth Observatory, the iceberg has broken up into a dozen smaller pieces of ice in the warmer waters. The initial fear, as the iceberg approached the island, was that the massive chunk of ice would smash into the seafloor near the island, cutting off foraging routes for penguins and seals that call the island home, not to mention crushing life on the seafloor. Back in January, the ice started following currents around the island, avoiding a direct hit. And now the warmer waters have led to the disintegration of the big berg, creating an “alphabet soup” of icebergs instead, with each broken bit of ice having its own name, beginning with A-68b and ending with A-68M.
If you want to learn more about how icebergs behave in the water, here’s your chance to experiment! Check out this site where you can draw an iceberg and see how it will float: https://joshdata.me/iceberger.html
Water is one of the few substances that is slightly denser as a liquid than as a solid and this is why ice floats in water. Most icebergs actually contain a lot of air as well – they are riddled with billions of tiny, trapped air bubbles, giving the huge bergs their white appearance. Finally icebergs are made from freshwater. Because of the dissolved salts in ocean water, it is denser than freshwater, adding buoyancy to icebergs.