Researchers studying glacial retreat on Baffin Island in the Canadian Arctic have discovered landscapes and plant life that have not been seen for more than 40,000 years.
The study, published Jan. 25 in the journal , also found that summers in the Canadian Arctic are warmer now than 鈥渁ny century in at least 115,000 years.鈥�
鈥淭he Arctic is currently warming two to three times faster than the rest of the globe, so naturally, glaciers and the ice caps are going to react faster,鈥� Simon Pendleton, the study鈥檚 lead author and a doctoral researcher at the University of Colorado, Boulder鈥檚 Institute of Arctic and Alpine Research, said in a .
鈥淚t鈥檚 stunning that you鈥檙e standing on the landscape that, not only has no humans ever stood on, but [that has] been ice-covered for over 100,000 years,鈥� he told 麻豆传媒 Channel.
He explained that during past cold climates, glaciers expanded and during warmer periods, those glaciers retreated.
鈥淎s these glaciers retreat, they鈥檙e exposing landscapes underneath them,鈥� Pendleton said. In other words, once glaciers in Canada鈥檚 eastern Arctic region thaw, they give researchers a snapshot of Earth鈥檚 past.
鈥淭hese glaciers in Baffin Island, in particular, are unique in that they鈥檙e frozen to the bed underneath them,鈥� he said. 鈥淪o as they expand over a plant [during periods of colder climates], they鈥檒l actually preserve it in its growth position -- where it was living before the glacier expanded.鈥�
Between 2010 and 2015, he and his team made trips to Baffin Island in Nunavut and noticed the glaciers there were rapidly shrinking. Due to global climate change, they saw them recede by tens of metres between each of their visits.
To draw their conclusions, researchers used radiocarbon dating to determine the ages of 48 mosses and lichen samples collected last August at 30 ice caps encompassing a range of elevations and exposures in Baffin Island in Nunavut.
The samples were preserved in the exact same spots where they once grew, beneath ice caps that cover the island鈥檚 high-elevation, low-relief plateaus. As the ice caps have receded, plants -- from moss to lichen -- have been exposed.
The samples were lacking radiocarbon, which suggests that they last saw the light of day at least 40,000 years ago. Researchers then cross-referenced those radiocarbon tests with measurements of radiocarbon in rock samples nearby. They, too, were bereft of radiocarbon.
According to the study, these results, combined with data from ice cores taken on Baffin Island and Greenland, suggest that the region is currently experiencing its warmest century in 115,000 years.
鈥淭hese trends are likely to continue and remove all ice from Baffin Island within the next few centuries,鈥� the study concluded, 鈥渆ven in the absence of additional summer warming.鈥�
Now, Pendleton鈥檚 team hopes past-glacial fluctuations will help scientists predict how human-made climate change will effect Earth鈥檚 ecosystems in the coming decades.
He said some of his peers at the University of Colorado, Boulder have already begun that work.
