Investigating ice-ocean interactions in Kangerdlugssuaq Fjord over the past ∼600 years through proxy reconstructions

International audience There is a growing body of evidence demonstrating that changes in warm water inflow to Greenlandic fjords are linked to the rapid retreat of marine-terminating outlet glaciers. This process is thought to be responsible for a substantial component of the increased mass loss fro...

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Main Authors: Vermassen, Flor, Sicre, Marie-Alexandrine, Jaeger, John, M, Wangner, David, J, Dyke, Laurence, M, Klein, Vincent, Kjaer, Kurt, H, Andresen, Camilla, S
Other Authors: Variabilité de l'Océan et de la Glace de mer (VOG), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), 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 Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), 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)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-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)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)
Format: Conference Object
Language:English
Published: HAL CCSD 2018
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Online Access:https://hal.science/hal-03503481
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Summary:International audience There is a growing body of evidence demonstrating that changes in warm water inflow to Greenlandic fjords are linked to the rapid retreat of marine-terminating outlet glaciers. This process is thought to be responsible for a substantial component of the increased mass loss from the Greenland Ice Sheet over the last two decades. Sediment cores from glaciated fjords provide high-resolution sedimentological and biological proxy recordswhich can be used to evaluate the interplay of warm water inflow and glacier calving over timescales longer than the instrumental record.In this study, a short core (1.5m) positioned at the head of Kangerdlugssuaq fjord is investigated to establish a multi-proxy record of glacier behaviour and oceanographic conditions. The core covers the past ∼600 years, spanning back to the start of the Little Ice Age. Grain-size analysis is performed to quantify ice-rafted debris (IRD), a parameter related to the calving intensity of Kangerdlugssuaq glacier. Bottom current strength isreconstructed by measurements of the mean sortable silt; periods of vigorous current flow are assumed to be due to enhanced warm water inflow. A record of sea surface temperatures is derived from alkenone paleothermometry (Uk’ 37), and the origin of the alkenones is discussed (in situ vs. advection). Reconstructions of ice-oceaninteractions on a longer timescale provide a baseline to better understand the recent -and potentially future- retreat of marine-terminating glaciers in Greenland.