Uncovering a 70-year-old permafrost degradation induced disaster in the Arctic, the 1952 Niiortuut landslide-tsunami in central West Greenland

• Published in: Science of The Total Environment
• Main Authors: Svennevig, Kristian, Keiding, Marie, Korsgaard, Niels, Jákup, Lucas, Antoine, Owen, Matthew, Poulsen, Majken, Djurhuus, Priebe, Janina, Sørensen, Erik, Vest, Morino, Costanza
• Other Authors: Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Environnements, Dynamiques et Territoires de Montagne (EDYTEM), Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS), ANR-18-IDEX-0001,Université de Paris,Université de Paris(2018), ANR-19-CE01-0010,Permolards,Les molards, marqueurs de l'évolution de la dégradation du pergélisol de montagne(2019), ANR-10-LABX-0023,UnivEarthS,Earth - Planets - Universe: observation, modeling, transfer(2010)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: [SDE.MCG]Environmental Sciences/Global Changes; Arctic; Greenland; Nuussuaq; Qullissat; Vaigat; permafrost
• Online Access: https://hal.science/hal-03846381; https://hal.science/hal-03846381/document; https://hal.science/hal-03846381/file/1-s2.0-S0048969722072102-main.pdf; https://doi.org/10.1016/j.scitotenv.2022.160110

International audience On December 15th 1952, at approximately 14:00 local time a mass of 5.9 × 106 m3 of permafrozen talus deposits failed in a landslide close to the Niiortuut mountain on the south coast of the Nuussuaq peninsula, central West Greenland. Between 1.8 and 4.5 × 106 m3 of the material entered the sea and generated a tsunami that propagated through the Vaigat strait (Sullorsuaq). Here we describe this catastrophic event for the first time by analysis of historical material supplemented by recent fieldwork and discuss the implications for the state of contemporary permafrozen slopes. The tsunami killed a fisherman working on the shore of southern Nuussuaq, 10 km south-east of the landslide. In the mining town of Qullissat, 30 km south of the landslide, it had a runup height of 2.2–2.7 m and caused minor material damage. Morphological evidence show that the basal surface of rupture was 80 m inside the permafrost cemented talus slope, whose degradation was a dynamic conditioning factor for the landslide. The 1952 Niiortuut landslide is the first historically recorded event of permafrost degradation induced landslide-tsunamis in the Arctic. We infer that the landslide and its cascading consequences occurred due to the early-twentieth century warming that started in the late 1910's in the Arctic. Warming is now increasingly affecting this region, as shown by an enhanced recent landslide activity.