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What is the News?
According to a study, the A68 iceberg that split off from Antarctica’s Larsen C ice shelf in 2017 was likely caused due to ice-shelf dynamics and not climate change.
What is the issue?
Ice shelves are massive stretches of ice that build up over many thousands of years.
Global warming contributes to the weakening of ice shelves as warmer ocean water erodes the underbelly of the ice shelves while rising air temperatures weaken them from above.
But this theory did not fit well with the A68 iceberg that split off from Antarctica’s Larsen C ice shelf in 2017. This is because the ice had been frozen solid for months.
Then what was the reason for the Larsen C ice shelf split?
To find the reason, NASA scientists studied the ice melange which has natural properties similar to glue: It fills cracks or gaps and sticks to ice and rock. When it accumulates in a crack in an ice shelf, it creates a layer — thin but as hard as the surrounding ice — that holds the crack together.
However, scientists observed that the layers of ice mélange melt when it comes in contact with the ocean water below. This process continues through the year, and the melange becomes too thin to keep holding the ice shelf together.
Hence, this might be the reason for the Larsen C Ice Shelf split, despite having frozen ice for months.
Source: This post is based on the article “Why did the Antarctic Larsen C ice shelf break in 2017? NASA has an answer” published in Down To Earth on 13th October 2021.