Morphological and evolutionary patterns of emerging arctic coastal landscapes: the case of northwestern Nunavik (Quebec, Canada)

Abstract

Northwestern Nunavik (Quebec, Canada) is characterized by specific landforms and poorly documented examples of emerging coastal landscapes. In this study, we identified the different types of coasts and examined how they were morphologically reworked and shaped during the Holocene. This coastal region is currently emerging at rates of 8–9 mm/year due to glacial isostatic adjustment. The coastal zone includes a large number of glacial and glaciofluvial landforms such as De Geer moraines, eskers, and drumlinoid ridges that are continuously modified by coastal processes as they emerge. Wave erosion, shore drifting, and sedimentation transform the original landforms into transverse spits, tombolos, dunes, beaches, and narrow tidal flats. Once raised above the reach of storm surges, the coastal landscape evolves into a maze of low tundra ridges, wetlands, and lakes, which represent the end point of rapid shoreline regression. Exposure to a cold climate allows permafrost inception and aggradation in the uplifted sediments, forming features such as ice-wedge polygons and frost boils. Conceptual models of coastal evolution and ecosystem formation are proposed, from the original submarine landscapes to the emerged landscapes.