This Glacier Is Losing Ice Faster Than Any Other in Antarctica

Author: Shaena Montanari / Source: Atlas Obscura

Down in the notoriously vulnerable ice sheet of West Antarctica, Pine Island Glacier seems to be breaking up faster than ever, and it’s looking like 2019 might be another busy year.

The ice shelf calved major icebergs in 2013, 2015, 2017, and 2018—and now, another one is getting ready to break free.

The instability of this glacier is not just bad for the southernmost continent. It is bad for the globe. This glacier is contributing more to sea level rise than any other in Antarctica. New research has shown that since 1979, Pine Island Glacier has lost 58 billion tons of ice per year, which makes it the biggest loser of the continent. Combined with its unstable neighbor, Thwaites Glacier, these glaciers are contributing one millimeter per decade to global sea level rise.

While large ice masses can appear solid, they are actually complicated, dynamically flowing systems. Miles-thick glaciers sit on the Antarctic continent as their ice slowly flows out to sea, creating a floating ice shelf that can calve icebergs. While this movement is a normal process, the frequent calving of icebergs and glacial landward retreat can indicate something out of the ordinary is happening. As the floating ice shelves retreat and shrink, the pressure on the land-based glacier gets relieved, allowing it to flow faster towards the ocean where it can then melt and cause sea level rise.

Thanks to satellite data from the European Space Agency’s Sentinel-1 satellite network, NASA’s Landsat satellite network, and NASA IceBridge reconnaissance flights, the acceleration of Pine Island Glacier has been monitored for decades from the sky. As far as the recent history of this glacier goes, in 2016, a rift started forming across the 22-mile-wide main trunk of the Pine Island ice shelf and eventually calved an iceberg called B-44 a year later in September 2017. Another rift appeared in September 2018, and only one month later, iceberg B-46 was calved from the glacier.

These icebergs may look small on the satellite images, but they are tens to hundreds of square miles in size. The most recent B-46 iceberg was over 70 square miles in area (by comparison, Manhattan is just over 22 square miles). This iceberg was seen by human eyes for the first time during a NASA IceBridge flight on November…

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