At a remote Siberian ice cap, scientists have made a first-of-its-kind discovery: the formation of an ice stream that is dumping mass into the ocean at a sustained rate over several years.
The Vavilov Ice Cap, one of several on the islands of Russia’s Severnaya Zemlya archipelago, has lost 11 percent of its mass since 2013, thanks largely to the newly formed ice stream, according to the scientists.
Their findings, the product of a wide range of satellite monitoring, are detailed in a study published in the journal Geophysical Research Letters.
Ice streams have been found previously in Antarctica and Greenland, but this is the first time that the creation of an ice stream has been documented, said Whyjay Zheng, a doctoral student at Cornell University and the study’s lead author.
What seemed at first to be a glacial surge, a somewhat common but temporary event that occurs as snow accumulations slump forward and glaciers stabilize, has turned out to be much more sustained and powerful, he said.
“In the satellite images, it seems like the entire west wing of the ice cap is just dumping into the sea,” Zheng said in a statement released by Cornell. “No one has ever seen this before.”
In addition to Cornell scientists, team members were from the University of Colorado and the University of Kansas. Funding for the project was provided by NASA and the Taiwan Ministry of Education’s Overseas Ph.D. Scholarship, Cornell said.
Glacial surges are typically independent of climate change and are the result of instability. They are usually short-lived.
The Vavilov situation emerged as something quite different.
In the six years that the team has been studying the ice cap, the glacial stream has developed into a triangular-shaped fan. Ice in the stream is moving fast, at an average rate of 1.8 kilometers a year, though in the center of the stream the movement is nearly twice that fast, according to the study.
Ice streams are especially efficient mechanisms for ice loss, and what is happening at the Vavilov Ice Cap is a warning for larger ice caps and the entire globe’s sea levels.
The big loss of Vavilov ice is irreversible, Zheng said.
“This is offering scientists another clue as to what happens during global warming. Now once the ice is lost, it is lost,” he said in the Cornell statement. “Suddenly, we have more water in the oceans.”