Rising global temperatures are causing frozen Arctic soil – permafrost – to thaw. In a new study, researchers have discovered something surprising: small rivers, creeks and streams that flow into larger lakes and coastal waters seem be to getting colder as permafrost melts.
Rising global temperatures are causing frozen Arctic soil – permafrost – to thaw. In a new study, researchers have discovered something surprising: small rivers, creeks and streams that flow into larger lakes and coastal waters seem be to getting colder as permafrost melts. The phenomenon was previously documented in Russian rivers in the Arctic. But until now, no one had studied why the water was getting colder, even as air temperatures are warming and the permafrost is thawing.
Together with researchers from the US Geological Survey Alaska Science Center, Associate Professor Ylva Sjöberg of UCPH’s Department of Geosciences and Natural Resource Management has shed new light on this cold water. The study’s researchers discovered that thawing permafrost causes groundwater to run deeper, where it becomes cooler than when it flows near the soil surface.
"Permafrost is found just beneath the ground’s surface. When permafrost is intact, groundwater flows from springs and the mountains and atop the permafrost layer, where it is significantly heated throughout summer. However, as permafrost disappears, runoff seeps deeper into the ground, where it cools before making its way into nearby streams, rivers and lakes," explains Ylva Sjöberg, the study’s lead author.
Read more at: University of Copenhagen - Faculty of Science
