Mapping Antarctica’s Hidden Melt. Much of Antarctica’s ice loss is happening underneath the surface–where ice that hangs off the edge of the continent touches ocean water. The more these ice shelves shrink, the faster ice on land can travel out to sea, increasing the potential for sea level rise. Notes: Ice sheet data from 2010–2018; temperature data mostly from 1990s-present
Sources: Susheel Adusumilli, Scripps Institution of Oceanography; Matthew R. Siegfried, Colorado School of Mines; Nature Geoscience
Excerpt from this story from the
Wall Street Journal:
The ice that hangs off the edge of Antarctica and floats on the ocean is melting faster than it is being replenished, even in pockets of East Antarctica typically thought to be less vulnerable to climate change, according to a study published Monday.
These structures, known as ice shelves, shed nearly 4,000 gigatons of their mass between 1994 and 2018, according to the new research, which leveraged nearly 25 years of satellite measurements of ice thickness. It echoes findings of numerous previous studies reporting the retreat and destabilization of Antarctic ice shelves but goes further, helping scientists understand the processes driving the melt around the entire continent over longer time periods and with high spatial resolution.
The study, published in the journal Nature Geoscience, is part of a relatively new scientific discipline that aims to understand how the ocean interacts with ice sheets. Ice sheets are massive swaths of ice that cover Antarctica and Greenland. The edges of ice sheets can spill over onto the ocean, forming ice shelves.
Ice-shelf meltwater doesn’t directly contribute to sea-level rise. Instead, the structures slow down the movement of ice flowing from the interior of the continent out to sea. The smaller they are, the less they hold back the flow and the faster ice on land can reach the ocean. That extra ice is what drives increases in sea levels.
