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

• Main Authors: Vermassen, Flor, Sicre, Marie-Alexandrine, Jaeger, John, Wangner, David, Dyke, Laurence, Klein, Vincent, Kjaer, Kurt, Andresen, Camilla
• Other Authors: 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)
• Format: Conference Object
• Language: English
• Published: HAL CCSD 2018
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology; Greenland; glacier; greenlandic; Ice Sheet
• Online Access: https://hal.archives-ouvertes.fr/hal-03503481

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.