Arctic ice shelves, epishelf lakes and basal channels
Arctic ice shelves in Canada are derived from thick coastal landfast sea ice along with glacial input in some places. These large ice features are not as extensive or as thick as Antarctic ice shelves but they represent the oldest (~1,400 – 5,000 years old) and thickest sea ice in the world. Over the course of the last hundred years, the Canadian ice shelves along the northern coast of Ellesmere Island have been reduced to 535 km2 from over 8,597 km2 (94% loss). This occurred over a period of pronounced atmospheric warming and created many large ice islands (extensive tabular icebergs) that drifted up to decades around the Arctic Ocean. Arctic ice shelves, like some of their Antarctic counterparts, have caused freshwater lakes to form to their landward sides by impounding a layer of meltwater that floats over the ocean. These so-called epishelf lakes have also changed dramatically as their ice shelf dams thinned and broke-up. Some of these lakes, which contain relatively warm water, have incised basal channels in the ice shelves that block them. We are investigating how the fate of ice shelves and epishelf lakes are intertwined along with the processes that may eventually destabilize the ice shelves and trigger break-up.