A study has shown that some Antarctic ice shelves have grown in the past two decades despite the fact that human activity has heated the planet.
The sea ice was blown into shelves by the change in wind patterns. These are thick slabs of ice floating on the shoreline.
Researchers think this trend may have prevented ice shelves from melting into the warming ocean.
The ice shelves prevent inland ice from being released into the ocean, thereby pushing up sea level.
The eastern Antarctic Peninsula saw a significant decrease in ice volume between the 1980s and 1990s. This was primarily due to the collapse of Larsen A and B ice shelves, which occurred in 1995 and 2002, respectively.
They said that 85% of the 870-mile-long ice shelf “underwent continuous advance” between 2003 and 2019.
Scientists from the UK’s Cambridge and Newcastle universities, as well as New Zealand’s Canterbury University, said that their observations “highlighted the complexity and often-overlooked significance of sea ice variability for the health of Antarctic Ice Sheet”.
To study the changes in shape and times of the ice shelf, they used satellite images that go back 60 years along with ocean and atmospheric records and models.
According to Nature Geoscience’s study, the increase in sea ice was caused by changes in atmospheric circulation.
“We found that sea-ice change can either protect from, or set into motion, the calving icebergs of large Antarctic ice shelves from Antarctic ice shelves,” stated Dr Frazer Christie (Cambridge’s Scott Polar Research Institute, SPRI).
“Regardless of whether the sea ice around Antarctica is changing in a warmer climate, our observations highlight how important sea ice variability is to the health and well-being of the Antarctic Ice Sheet.”
Julian Dowdeswell (also from the SPRI) was the expedition’s chief scientist and co-author. He said that the study had shown that some ice-shelf coastlines were in their “most advanced position” since the 1960s, when satellite records began.
Scientists are still not able to agree on how the climate crisis is going to affect Antarctica’s huge ice shelves and its impact on sea level rise.
While some models predict sea ice loss across the Southern Ocean, others project sea ice growth.
According to research, icebergs could break apart in 2020 and signal a shift in atmospheric patterns that could lead to a return of losses.
Dr Wolfgang Rack from the University of Canterbury, one of the paper’s coauthors, stated: “It is entirely possible that we could see a transition back into atmospheric patterns similar to the ones observed during the 1990s which encouraged sea ice reduction and, ultimately more ice-shelf caving.”
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