Satellite imagery shows rapid ice loss in a remote Arctic ice cap, vanishing in front of our eyes.
Nordsaustlandet island in Norway is home to the Austfonna ice cap, which has thinned by more than 50 metres since 2012 in some parts, one-sixth of the ice’s thickness.
Information garnered from eight satellites, including Sentinel-1A and CryoSat, by a team of scientists from Leeds discovered this reduction in the ice – the surrounding sea temperature levels may well have increased in recent years, which would lead to increased melting.
“These results provide a clear example of just how quickly ice caps can evolve, and highlight the challenges associated with making projections of their future contribution to sea level,” said the study’s lead author, Mal McMillan, finding that the melting process is indeed 25 times faster than previously thought.
The main figure (top) shows the rate of ice cap elevation change between 2010 and 2014. Red indicates that the ice surface is lowering. A closer look at the south-east region is shown in the four smaller figures below. Image via CPOM/GRL
The fast and the furious
Two weeks ago, researchers in Greenland discovered huge swathes of melted ice beneath the glaciers in the country, leaving huge vacuums as sub-glacial lakes flowed away, removing the support for the topographical layer seen from above.
Again it was from viewing these frozen structures from above that researchers could establish the gravity of the situation, with technology and knowledge not yet capable of establishing issues from below in many instances.
“New satellites such as Sentinel-1A and CryoSat are essential for enabling us to systematically monitor ice caps and ice sheets, and to better understand these remote polar environments,” said McMillan.
It’s estimated that melting ice is, at least in part, responsible for the recent rise in sea levels. However, it is almost impossible to track just how big a part it plays as it is so difficult to establish the size and make up of certain areas of ice, let alone the quickening pace with which it melts.
Sentinel-1, the first in the family of Copernicus satellites, has documented melting ice caps. Image via ESA/ATG
Andrew Shepherd, director of the CPOM which helped lead the Leeds team, said the results were “spectacular”.
“Until recently ice caps in this part of the world were surrounded by sea ice,” he told The Yorkshire Post. “That has receded dramatically and the ice caps are now being exposed to warmer water
“Whether or not the warmer ocean water and ice cap behaviour are directly linked remains an unanswered question. Feeding the results into existing ice flow models may help us to shed light on the cause, and also improve predictions of global ice loss and sea level rise in the future.”
Arctic ice image via Shutterstock