A highly important glacier in Antarctica, the Pine Island Glacier, was found to be melting from inside out, which suggests that the ocean is weakening ice on the continental edges. The glacier is part of the ice shelf binding the West Antarctic Ice Sheet and is one of the most likely shelves to go through a massive retreat.
The immediate consequence of its melting would be flooding the coastlines across the globe. The study of this phenomenon was published on Nov. 19 in the journal Geophysical Research Letters and brings evidence to the idea that a rift formed at the base of the ice shelf approximately 20 miles inland in 2013.
The Antarctic Meltdown
The rift set the iceberg adrift in July and August 2015 after a two-year upward propagation. According to Ian Howat, the lead author of the study, the melting of the West Antarctic Ice Sheet is inevitable.
"This kind of rifting behavior provides another mechanism for rapid retreat of these glaciers, adding to the probability that we may see significant collapse of West Antarctica in our lifetimes," noted Howat.
As scientists from the the Ohio State University were testing a new imaging software, they observed a bizarre activity in the 225-square-mile iceberg. This was the very first time that scientists have observed a deep surface rift being created underneath the Antarctic ice. However, similar activity has been documented at the level of the Greenland Ice Sheet, where ice was being melted from underneath because of the ocean water having seeped inland.
New Imaging Technique Confirms Antarctic Rifts
According to Howat, this imaging technique represents the first concrete proof that the ice shelves of the Antarctic behave similarly to the ones in Greenland. Generally, the rifts are formed at the exterior of an ice shelf, where the ice layer is considerably thinner and therefore more susceptible to breakage.
As this type of backward activity is quite unusual when it comes to ice sheets, Howat noted that a plausible explanation for this phenomenon would be a crevasse that melted out at the bedrock level.
This study is highly relevant, as Antarctica is the geographical conglomerate gathering more than half of the world's frozen water. The importance of the two glaciers, Pine Island and Thwaites, lies in protecting the ice flow, which helps approximately 10 percent of the West Antarctic Ice Sheet from draining.
However, this is not the first study to confirm the idea that the West Antarctic ice shelf is undergoing a precarious situation. Only in October two studies were conducted at NASA and the University of California, suggesting that the glaciers are retreating at an alarming rate because of the warm water beneath the ice shelf.
But different researches seem to be showing different data. According to another new study, Antarctica's ice hasn't suffered any spectacular changes in the past century.
Comparing Antarctic sea ice level data in the log books used during the Heroic Age of Antarctic Exploration dating from 1897 to 1917 with contemporary data, researchers noted that the Antarctic ice levels undergo different periods characterized by different types of activity, but they are not to be correlated with global warming and climate change.