Snow avalanches as the main geomorphic active process on hillslopes in Nunavik, Canada

In Nunavik, northern Quebec, Canada, ongoing climate change disturbs the nival regime. The study of deposits on talus underlines the predominance of snow avalanches as the main contributor to present-day slope development. In Tasiapik valley, close to the village of Umiujaq (56°32'35"N, 76°27'43"W), several automatic time-lapse cameras are operating year-round since 2017 along with VDTSILA weather station since 2012. The set of cameras enables monitoring target sections of the slope. The recorded snow avalanches correspond to slab and loose snow avalanches; many are triggered by the collapse of the ridgeline snow-cornices. The most active snow-avalanche season corresponds to late spring (June), when wet snow avalanches occurred after rain-on-snow events and rapid temperature rise, being then in contact with the regolith, therefore responsible of debris transfer downslope. However, the longest runout distance snow avalanches occur during the winter time, in April, after sudden temperatures changes or heavy snowfall. However, by comparing the snow-avalanche activity from other slopes (lake Wiyâshâkimî, 56°16'43"N, 74°27'48"O and Kangiqsualujjuaq, 58°41'33"N, 65°57'32"O) equipped with the same monitoring system, great variations appear in snowfall amount, snowdrift accumulation and triggering factors, sketching the role of continentality and latitude. In addition, in the vicinity of newly established villages due to the forced settlement of indigenous populations, snow avalanches represent a worrying hazard.