Quaternary Hydrodynamic Contexts of the Emerging Coasts of Nunavik (Northern Québec, Canada)

Abstract

Boisson, A. and Allard, M., 2018. Quaternary Hydrodynamic Contexts of the Emerging Coasts of Nunavik (Northern Quebec, Canada). In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 616–620. Coconut Creek (Florida), ISSN 0749-0208.Nunavik (northern Quebec, Canada) is bounded by Hudson Bay to the West and by Hudson Strait and Ungava Bay to the North. These understudied Arctic and Subarctic shores are undergoing glacio-isostatic uplift, with current emergence rates of 5 to 13 mm/yr., counterbalancing the current rise of sea level. A study of the effects of Quaternary hydrodynamic conditions on the emerging coastal geomorphology of Nunavik was conducted based on geotagged videography and photography collected by helicopter between Kuujjuarapik and Kangiqsualujjuaq in August 2015 and August 2016. In total, 45 hours of videography and 37,000 high resolution photographs were taken along the coast. Through detailed segmentation and characterization of that ~ 10,000 km long coastline, one of our main objectives is to better understand the shaping of the emerging coastlines by hydrodynamic processes (waves, tides, sea-ice). The results of this study emphasize on a strong trichotomy between these seaboards because they are very different in terms of tidal conditions, wind and sea-ice climate, morphology and coastal permafrost. In relation to these specific hydrodynamic contexts, conspicuous and poorly documented emerging landforms were identified and described such as boulder barricades along the coast of Ungava Bay, and reworked De Geer moraine ridges along the northeastern coast of Hudson Bay. Coastal risks in Nunavik are also briefly discussed.