This activity will develop new methods to detect and predict the presence of taliks (unfrozen ground in areas of permafrost often found beneath lakes and rivers). It will also explore new ways of understanding the flows and connectivity of surface water (lakes) and groundwater (below the base of permafrost) through these unfrozen (talik) and often fractured bedrock areas. Inadequate knowledge about the presence of taliks and processes related to groundwater flow taking place in taliks can impact mining operations, water management, and surrounding lakes (e.g., inflow of hypersaline groundwater; lake level lowering and reduction of groundwater flow to neighboring lakes connected by taliks). The knowledge acquired through the proposed research will assist in planning mine development and assessing potential impacts of mining activities and the effect of climate change on lakes and groundwaters.Our field operations will be based out of Rankin Inlet with no camp being established, no structures being erected on land and no long-term development. Municipal systems will be used for all infrastructure needs including waste disposal and water supply. Field operations will be conducted by truck, ATV, and snowmobile using established access trails and snowmobiles routes.The study will take place within the vicinity of the Rankin Inlet area (radius of 25-30 km) in 2023 and 2024. In spring 2023, 2 weeks of fieldwork will be required for water sampling, in-situ water properties measurements, and geophysical (on lake ice) measurements in deep lakes (~>2m depth). During summer 2023, 2 weeks of fieldwork will be required for water sampling, semi-permanent installation of lake bottom instruments in shallow lakes (~<2m depth) that are completely frozen in winter (via small inflatable boats), and permafrost coring. In summer 2024, fieldwork would involve follow-ups at established sites for data collection and retrieval of semi-permanent instruments.The study of Rankin Inlet’s water bodies will include the use of a Niskin sampling bottle (to collect lake water samples), a multi-parameter water probe (to assess the physicochemical characteristics of the lakes), passive diffusion samplers (to detect the nature and amount of dissolved gases in the water column), and semi-permanent installation of 1-2 osmosis pumps (to collect waters in 1-2 lake during an entire year). A small two-person hand drill will also used to collect permafrost core samples of in 2-3 locations near Rankin Inlet. Finally, a ground-based geophysical survey device will be dragged along the lake ice surface (or behind a boat) and uses electromagnetic sensing technology to measure the thickness of unfrozen ground beneath lakes.