Crucial Antarctic Ice Shelf Collapses in Just Three Days
According to a new study, Larsen-B, a huge section of the Larsen Ice Shelf in Antarctica shattered and fell into the ocean. Researchers are still unsure as to the exact reason why Larsen-B fell, but warm summer temperatures and winds are likely culprits. With nearby glaciers no longer supported by the ice and exposed to the sea, they could float away and melt much faster, contributing to rising sea levels.
Why This Matters
Global warming is shrinking glaciers and ice shelves throughout the Arctic and Antarctic. Antarctica’s Thwaites Glacier (the "Doomsday Glacier”) could collapse in just 3 to 5 years, resulting in a global sea level rise of up to 25%. In July 2020, A68a, the world’s largest iceberg, broke off of the Larsen Ice Shelf. It dumped enough water into the ocean to fill over 60 million Olympic-sized swimming pools. If climate change continues unchecked, sea levels will rise to untenable levels. In February, the NOAA predicted that over the next 30 years, the US coast will see its sea levels rise to about a foot, making hurricanes and storms even more damaging than they are now.
PBS: Melting of the Thwaites Glacier could rewrite the global coastline, December 15, 2021.
NASA: Journey of Antarctica's A-68A - The Voyage of One of the Planet's Largest Icebergs, April 21, 2021.
CNN: 'Mind boggling' - See how rising sea levels will affect the coasts, February 17, 2022.
Why Did Larsen-B Collapse So Quickly?
The last time parts of Larsen-B collapsed was in 2002, when warmer ocean waters melted it from below, and previously melted water on its surface sped up the thawing process. But this most recent collapse of Larsen-B is harder to explain, especially because it happened quickly -- over just three days.
"It’s difficult to tell what actually caused the disintegration as the sea ice was already showing cracks prior to the breakup,” said Stef Lhermitte, a geoscience and remote sensing researcher at the Delft University of Technology, in a press release. Adding, "…such rapid breakups are often typical for fast ice, as fast ice is often a frozen collection of loose sea ice segments. Once this breaks, it quickly disintegrates.”
But this isn’t the end for the Larsen Ice Shelf. The Larsen-D portion of the shelf remains stable, as its location near the South Pole has insulated it from the effects of climate change. But if the world doesn’t reduce its emissions, this may change and put the entire ice shelf at risk.
MSNBC: 'Doomsday Glacier' - Experts Raise Alarms About Cracking Antarctic Ice Shelf, December 30, 2021.
WW0 Conversation: Dr. Michalea King and John Kerry Instagram Live conversation streamed on 9/24/2020.
NOAA: Sea Level Rise Report Release, February 15, 2022.