Melting glaciers in the Canadian Arctic have led to the discovery of landscapes that had been hidden in the area for more than 40,000 years, researchers from University of Colorado Boulder have found.
As part of the study, published in the Nature Communications journal, researchers from the university’s Institute of Arctic and Alpine Research collected and studied 48 plant samples retrieved from the edges of 30 different ice caps of varying elevations and exposures on Canada’s Baffin Island.
By using radiocarbon dating, researchers discovered that the plants they found had been hidden under the ice for at least 40,000 years. They also collected quartz samples from each site to confirm their findings about the landscape’s age and ice cover history over the centuries.
“We travel to the retreating ice margins, sample newly exposed plants preserved on these ancient landscapes and carbon date the plants to get a sense of when the ice last advanced over that location,” lead author Simon Pendleton said in a statement. “Because dead plants are efficiently removed from the landscape, the radiocarbon age of rooted plants define the last time summers were as warm, on average, as those of the past century.”
The plants are preserved beneath the ice margins, appearing only when the glaciers start to melt out. Signals on the unaltered ice itself — including a large amount of bubbles and bits of dirt hidden within it — suggest that the ice covering these plants is ice that still remains from the last ice age and hasn’t experienced melting in modern times, until recently, researcher and professor Gifford Miller explained in a video filmed a few years ago while collecting samples on Baffin.
These plants had been buried under glacial ice for more than 40,000 years, and “almost certainly continuously buried” since the start of the last glaciation some 120,000 years ago, he explained.
The plants’ age combined with temperature data reconstructed from Baffin and Greenland ice cores has led researchers to suggest that the current temperatures in Baffin show the warmest century the region has experienced in the last 115,000 years. And that could be an alarming finding when it comes to the rate of ice melting in the area.
“You’d normally expect to see different plant ages in different topographical conditions,” Pendleton said in the statement. “A high elevation location might not hold onto its ice longer, for example; but the magnitude of warming is so high that everything is melting everywhere now.”
The evidence suggests that Baffin could be completely free of ice in the next few centuries.
“We haven’t seen anything as pronounced as this before,” Pendleton said.