The 200-foot-tall (60-meter-tall) front of the Getz Ice Shelf in Antarctica is scored with cracks where icebergs are likely to break off, or calve, in this 2016 photo. The first estimate of Antarctic calving has found that since 1997 ice shelves have lost as much ice from calving as from melting. Credit: NASA/GSFC/OIB
In Brief:
New research on Antarctica, including the first map of iceberg calving, doubles the previous estimates of loss from ice shelves and details how the continent is changing.
The greatest uncertainty in forecasting global sea level rise is how Antarctica’s ice loss will accelerate as the climate warms. Two studies published Aug. 10 and led by researchers at NASA’s Jet Propulsion Laboratory in Southern California reveal unexpected new data about how the Antarctic Ice Sheet has been losing mass in recent decades.
One study, published in the journal Nature, maps how iceberg calving – the breaking off of ice from a glacier front – has changed the Antarctic coastline over the last 25 years. The researchers found that the edge of the ice sheet has been shedding icebergs faster than the ice can be replaced. This surprise finding doubles previous estimates of ice loss from Antarctic’s floating ice shelves since 1997, from 6 trillion to 12 trillion metric tons. Ice loss from calving has weakened the ice shelves and allowed Antarctic glaciers to flow more rapidly to the ocean, accelerating the rate of global sea level rise.
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The other study, published in Earth System Science Data, …