Drilling 613 m through Müller Ice Cap, Nunavut, Canada – Advances in drill equipment, innovations in camp infrastructure, first results from the ice core, and insights into the basal material beneath the ice

From late March to late May 2025, a collaboration between Canada and Denmark drilled a 613-meter ice core through the Müller Ice Cap in the Canadian high Arctic. It is the deepest ice core in the Americas to date. The ice cap is in close proximity to the Arctic Ocean, supporting the primary goal of understanding the evolution of Arctic sea ice over the 10,000+ year record contained within the ice.For the drilling, we utilized a newly designed intermediate winch and control system, combined with a previously existing tower, and the Danish deep drill system featuring 2.2 m core barrels. The newly designed winch is staged on a movable platform, resulting in a fixed level wind and a short distance to the tower.Furthermore, we tested an inflatable tent to host the drilling and core processing. This worked well and withstood multiple days with strong winds and gusts above 40kt. The tent was a fraction of the weight of a traditional steel-framed tent.Drilling concluded after 30 drilling days with 10m of debris-rich, silty ice by hitting bedrock at 612.98m depth. We drilled through numerous sandstones using carbide inserts on the ice core drill, and we recovered samples for optically stimulated luminescence dating.The first results from the stable water isotopes (δ18O) and electric conductivity measurements (ECM) provide a profile over the full Holocene, as well as the transition from the Younger Dryas and Bølling-Allerød.