• Earth last month recorded the second-warmest March since at least 1850

The huge, long-lived iceberg known as B-22A, which has been anchored off the Antarctic coast for more than two decades, began moving out to sea in a northwesterly direction in late 2022.

The movement of this immense ice block of more than 3,000 square kilometers, according to scientists, could affect the nearby Thwaites Glacier, one of the largest contributors to global sea level rise due to the West Antarctic ice sheet.

Precisely, the iceberg B-22A is the largest remaining piece of the giant iceberg that broke off from that same glacier in early 2002. The block, located in the Amundsen Sea, got stuck on land in 2012 and has remained stationed in a relatively shallow part of the sea just 100 kilometers from its birthplace.

According to Christopher Shuman, a glaciologist at the University of Maryland, warm waters reaching the Amundsen Sea inlet have likely been thinning the iceberg from below, which could have helped it lose contact with the shallow seafloor and allow wind, waves and tides to wash it away.

As for its long life, it is uncommon, but not unheard of, for an iceberg to persist for so long. "More than twenty years is a long-lived iceberg, generally speaking," explains Shuman.

Icebergs on land play an important role in stabilizing the area's sea ice, which in turn helps reinforce glacial ice on the coast and slow its flow out to sea. While icebergs don't contribute to sea level rise (because they're already floating in the ocean), land ice from glaciers does.

  • Climate change

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