A new study suggests that a formerly stable part of the Greenland Ice Sheet is now melting at an alarming rate. The newly discovered development may lead to a further rise in global sea levels.
The Greenland Ice Sheet is one of the world's largest ice sheets and the rate at which it melts is one of the key factors contributing to rising sea levels. While scientists have been keeping a close watch on the ice sheet, what used to be a stable part in the northeastern section of the ice sheet is now melting at an accelerating pace.
This particular section of the Greenland Ice Sheet has been stable for a quarter of a century. However, recent data collected by scientists now indicates that the speed of the section's melting has tripled since the year 2003. The international team of scientists who worked on the study published their findings in the online journal Nature Climate Change.
"The northeast Greenland ice stream, which extends more than 600 km into the interior of the ice sheet, is now undergoing sustained dynamic thinning, linked to regional warming, after more than a quarter of a century of stability," the abstract of the study read. "This sector of the Greenland ice sheet is of particular interest, because the drainage basin area covers 16% of the ice sheet (twice that of Jakobshavn Isbræ) and numerical model predictions suggest no significant mass loss for this sector, leading to an under-estimation of future global sea-level rise."
The study showed that the Zachariae ice stream, a stream of ice connected to the outlet of the northeastern part of the Greenland Ice Sheet, has retreated by a total of 12.4 miles over the past ten years.
"Nature is changing faster than expected and seems to respond much stronger than expected to small fluctuations," said Shfaqat Khan, a senior researcher from the Technical University of Denmark and one of the authors of the study. "This also means that predictions of future sea level rise need to be revised."
The changes in the stability of the Greenland Ice Sheet means that scientists will have a more difficult time trying to estimate the effect of the increased melting on global sea levels. Moreover, the worsening effects of climate change will also play a large part in the future of the Greenland Ice Sheet.
"This is the first time anyone has ever observed a sudden acceleration of ice loss in the downhill (outlet) portions of a really long ice stream," said Ohio State University professor of geodynamics Michael Bevis. "So, we are in terra incognita."
