The deepest ice core ever drilled in the Americas — reaching 613 meters — has been pulled from the Müller Ice Cap on Axel Heiberg Island, Nunavut by an international research team co-led by a University of Alberta researcher who is hoping to unlock an untold record of Arctic climate and ocean variability from as far back as 20,000 years ago.
"Such a remote site, at the edge of the Arctic Ocean, will offer unprecedented insight into the long-range atmospheric transport of environmental contaminants to the far North — reconstructions of great importance both to science and to local communities," says Alison Criscitiello, U of A director of the Canadian Ice Core Lab and researcher in the Department of Earth and Atmospheric Sciences.
After nearly two months of drilling, often in temperatures that dipped below -30 C, the drill team reached bedrock on May 17, also recovering pebbles and sand from beneath the ancient ice. This deep ice core, along with the recovered geological material, will be transported to the Canadian Ice Core Lab at the U of A for analysis.
Criscitiello says the significance of this core's location cannot be overstated, noting that unlike cores drilled on the eastern edge of the Canadian Arctic Archipelago along Baffin Bay, this new core is uniquely positioned to reveal long-term changes – perhaps as far back as 20,000 years — in Arctic Ocean sea ice, a critical indicator of global climate health.
"Because of where this ice cap sits on the western edge of the Canadian Arctic Archipelago, we expect it to contain a very long record of Arctic Ocean variability that other island ice caps don't," she says.
Criscitiello's team is particularly excited to study elements like sea salts and halogens, which are deposited in snow but originate from the ocean, and can help reconstruct past sea ice conditions.
