On a remote island in the Canadian Arctic, researchers discovered: remains of ancient glaciers It could be over a million years old. The discovery indicates that it may be the oldest glacial ice found buried in the Arctic’s permafrost (ground that has been frozen for at least two consecutive years), researchers reported Jan. 1. geology. The clock is ticking for researchers working on glaciers, as human-caused climate change is causing long-preserved ice to melt.
Like a note on a journal page, the air bubbles, compounds and particulates trapped in a glacier’s ice layer can provide information about the atmosphere and climate of past thousands of years. But there are few reports of ice older than the last great expansion of the ice sheet 26,000 to 20,000 years ago. The newly discovered ice could therefore give researchers a rare opportunity to study the climate of the early Pleistocene era. During this period, Earth experienced intermittent ice ages separated by warm periods known as interglacial periods. “These [Pleistocene climate shifts] “It’s similar to what we might see in the future,” said Daniel Fortier, a geomorphologist at the University of Montreal.
In 2009, while studying buried fossilized forests on Bylot Island in Nunavut, Canada, Fortier and colleagues stumbled across the site of a recent landslide caused by thawing permafrost. The slide exposed a translucent layer of ice that was buried several meters underground, just above the fossil forest. To Fortier’s surprise, radiocarbon dating of the organic matter in the ice revealed that it was over 60,000 years old. “I never expected it,” he says.
Moreover, in the sediment layer overlying the ice, the researchers found a reversal in the arrangement of magnetic minerals consistent with a reversal of the Earth’s magnetic field that is roughly 770,000 years old, indicating that the ice is at least that old. And previous studies have dated the fossil forest in which the glacier is located to about 2.8 to 2.4 million years ago, giving the maximum possible age for the ice.
The discovery is evidence of the resilience of permafrost, Fortier says. Although climate projections predict permafrost will completely melt in many regions by the end of this century, these preserved glaciers persisted even during interglacial periods that were warmer than today, he notes. “I don’t think permafrost will disappear that quickly. “The system is more resilient than we think.”
