Canadian Arctic fjords: The fate of floating ice in a changing environment

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Major transformation is currently underway in terrestrial, marine and cryospheric environments in the Arctic. Coastal environments, such as fjords, where watersheds, glaciers, meltwater, floating ice and ocean interact, are particularly vulnerable and poorly understood. Climate warming has already altered the thick ice shelves that have existed at the mouth of fjords along Canada's northernmost coast for 5500 years. Over the last 2 decades, they have lost 57% of their areal extent in break-up events, including a recent calving of the Milne Ice Shelf. Meanwhile, seasonal landfast sea ice in other fjords near communities is also prone to episodes of break-off. These events are now more numerous, are coming earlier and are not easy to predict, putting those who use this ice at risk. My team of graduate students and collaborators will work at Milne Fiord in the Tuvaijuittuq Marine Protected Area (known as the "Last Ice Area") to examine the fjord as a coastal system. We will explore how runoff in the watershed has changed in the past and will evolve in the future. We will examine the large marine-terminating glacier at the head of this fjord to understand how and why its grounding line is shifting. This relates to oceanographic processes within the fjord, especially ice-ocean interaction. Fjord-scale processes will be represented by a state-of-the-art 3D model, which will be validated by data from our long-term mooring. We can then simulate the system response to the loss of the Milne Ice Shelf or understand the evolution of the freshwater layer between the glacier and the ice shelf. Milne Ice Shelf itself will be studied to better understand variation in ice thickness and the growth of melt ponds in summer. This information will be used to model stress and flexure across the ice and evaluate the contribution of ice morphology and meltwater to fracture. Fracture and break-off of landfast sea ice can be a hazard for Inuit and this process begins with the development of key flaws in the ice. At the mouth of Admiralty Inlet, in the Tallurutiup Imanga National Marine Conservation Area, the most important flaws are cross-fjord and along-shore leads. Cross-fjord leads appear in mid-winter due to mechanical stress, whereas along-shore leads grow in the spring and are influenced by heat from both the terrestrial and marine environment. Fieldwork will elucidate important processes at the shoreline, while cross-fjord leads will be followed using advanced remote sensing techniques. My research program will help determine the implications of the profound environmental transformation now underway in the Arctic. I will provide graduate training in glaciology, hydrology and oceanography using state-of-the-art modelling, remote sensing and field techniques in Nunavut. Our research explores topics of fundamental importance to Northerners and is critical for understanding processes of global significance, such as sea level rise and freshening of the Arctic Ocean.