A Major Collapse of Kangerlussuaq Glacier's Ice Tongue Between 1932 and 1933 in East Greenland

• Published in: Geophysical Research Letters
• Main Authors: Vermassen, Flor, Bjørk , Anders A., Sicre, Marie-Alexandrine, Jaeger, John M., Wangner, David J., Kjeldsen, Kristian K., Siggaard-Andersen, Marie-Louise, Klein, Vincent, Mouginot, Jeremie, Kjær, Kurt H., Andresen, Camilla S.
• Other Authors: Centre for GeoGenetics, Natural History Museum of Denmark, Faculty of Science Copenhagen, University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU)-Faculty of Science Copenhagen, University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU), Geological Survey of Denmark and Greenland (GEUS), Variabilité de l'Océan et de la Glace de mer (VOG), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU), Department of Geological Sciences Gainesville (UF|Geological), University of Florida Gainesville (UF), Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Department of Earth System Science Irvine (ESS), University of California Irvine (UCI), University of California-University of California, NAIV project funded by LEFE/INSU, Carlsberg Foundation (Grant CF17‐0529), VILLUM project “Past and Future Dynamics of the Greenland Ice Sheet: what is the ocean hiding?”
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: [SDE]Environmental Sciences; [SDE.MCG]Environmental Sciences/Global Changes; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology; [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; Greenland; Kangerlussuaq; East Greenland; glacier; greenlandic; North Greenland
• Online Access: https://hal.archives-ouvertes.fr/hal-02870123; https://hal.archives-ouvertes.fr/hal-02870123/document; https://hal.archives-ouvertes.fr/hal-02870123/file/2020-Vermassen%20et%20al,%20GRL2020.pdf; https://doi.org/10.1029/2019GL085954

International audience In recent years, several large outlet glaciers in Greenland lost their floating ice tongue, yet little is known regarding their stability over a longer timescale. Here we compile historical documents to demonstrate a major ice tongue collapse of Kangerlussuaq Glacier between 1932 and 1933. This event resulted in a 9-km retreat, exceeding any of the glacier's recent major retreat events. Sediment cores from the fjord are used to reconstruct sea surface temperatures and to investigate a potential sedimentological trace of the collapse. During the 1920s, local and regional sea surface temperatures and air temperatures increased rapidly, suggesting a climatic trigger for the collapse. Fjord bathymetry played an important role too, as the (partially) pinned ice tongue retreated off a submarine moraine during the event. This historical analogue of a glacier tongue collapse emphasizes the fragility of remaining ice tongues in North Greenland within a warming climate. Plain Language Summary In the past two decades, multiple Greenlandic glaciers retreated because their floating part (="ice tongue") melted and broke off. While it is believed that such events are the result of a warming climate, not much is known about how often or when such events have occurred in the past. In this study, we compiled multiple historical sources to show that Kangerlussuaq Glacier, one of Greenland's largest glaciers, retreated drastically between 1932 and 1933. During this event the ice tongue collapsed, leading to a 9-km retreat, which is more than during any of the glacier's recent retreat events. By studying fjord sediments we show that the ocean temperatures increased prior to the event, as did air temperatures. Thus, climatic warming likely triggered the collapse. While other glaciers had already started their retreat decades earlier, Kangerlussuaq Glacier had been stable until 1932, probably due to stabilizing effect of an underwater moraine. Overall, this study emphasizes that ice tongues are sensitive to ...