Thermal regime variability of islands in the Lena River near Yakutsk, eastern Siberia

• Published in: Permafrost and Periglacial Processes
• Main Authors: Costard, François, Gautier, Emmanuèle, Konstantinov, Pavel, Bouchard, Frederic, Séjourné, Antoine, Dupeyrat, Laure, Fedorov, Alexander
• Other Authors: Géosciences Paris Saclay (GEOPS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Melnikov Permafrost Institute, Siberian Branch of the Russian Academy of Sciences (SB RAS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology; Arctic; Yakutsk; Four Islands; Ice; lena river; permafrost; Permafrost and Periglacial Processes; Siberia
• Online Access: https://hal.science/hal-03821050; https://hal.science/hal-03821050/document; https://hal.science/hal-03821050/file/Costard%20et%20al_Lena-Islands_v7.pdf; https://doi.org/10.1002/ppp.2136

International audience Recent evidence has shown that Arctic regions have warmed about twice as much as elsewhere on the planet over the last few decades, and that high-latitude permafrost–periglacial processes and hydrological systems are notably responsive to rising temperatures. The aim of this paper is to report on the thermal regime of islands located along the Lena River floodplain, upstream of the city of Yakutsk (eastern Siberia). Four islands were monitored using waterproof dataloggers and continuous monitoring of frozen soil in contact with ice breakup of the Lena River. For each of these islands, we measured: (a) ground surface temperature, air and frozen soil temperatures at different depths; and (b) submersion duration during the flood. Our results show that within a zone of thick and continuous permafrost, the Lena floodplain is notably heterogeneous, with a combination of permanently and seasonally frozen islands. The ice breakups seem to have a negligible impact on the ground thermal regime. Our study confirms that relatively young (<30 years old) islands, composed of fine sand material, appear less prone to permafrost formation compared to older islands with ice-rich silty material.f