Scientists say Antarctica's ice shelves are shrinking rapidly.
New research shows 40% of these floating shelves have significantly reduced in volume over the past quarter-century.
According to the study published in the journal Science Advances, 48 ice shelves have shrunk by 30% or more since 1997 -- and 28 shelves had shrunk by more than half.
Scientists are worried that melting ice from the North and South poles could cause sea levels to rise and impact marine life.
The study is based on 100,000 satellite radar images to produce a major assessment of the state of the health of Antarctica's ice shelves.
"These massive floating extensions of the continent's ice sheet play a crucial role in stabilizing the region's glaciers by acting as buttresses, slowing the flow of ice into the ocean. The Antarctic, therefore, faces a double whammy – as the ice shelves get smaller, the rate of ice lost from the ice sheet increases," the European Space Agency, which funded the study, said in a statement.
The research team found that 71 of the 162 ice shelves around Antarctica have reduced in volume, releasing almost 67 trillion tons of meltwater into the ocean. Moreover, researchers found that almost all the ice shelves on the western side of Antarctica experienced ice loss, while most of the ice shelves on the eastern side remained intact or increased in mass.
The Getz Ice Shelf experienced some of the biggest ice loss, where 1.9 trillion tons of ice were lost over the 25-year study period. Just 5% of this was caused by calving, where large chunks of ice breakaway from the shelf and fall into the ocean, while the rest was due to melting at the base of the ice shelf, according to the study.
"We expected most ice shelves to go through cycles of rapid, but short-lived shrinking, then to regrow slowly. Instead, we see that almost half of them are shrinking with no sign of recovery," Benjamin Davison, a research fellow at the University of Leeds, said in a statement.
All told, Antarctic ice shelves lost about 8.3 trillion tons of ice over the 25-year study period, according to the Associated Press, which analyzed the data. That amounts to around 330 billion tons a year, which is similar to previous studies.