Ice loss in the Northeastern Tibetan Plateau permafrost as seen by 16 yr of ESA SAR missions

• Published in: Earth and Planetary Science Letters
• Main Authors: Daout, Simon, Dini, Benedetta, Haeberli, Wilfried, Doin, Marie-Pierre, Parsons, Barry
• Other Authors: Centre de Recherches Pétrographiques et Géochimiques (CRPG), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Ecole Nationale Supérieure de Géologie (ENSG), Université de Lorraine (UL), University of East Anglia Norwich (UEA), Universität Zürich Zürich = University of Zurich (UZH), Institut des Sciences de la Terre (ISTerre), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Gustave Eiffel-Université Grenoble Alpes (UGA), Department of Earth Sciences Oxford, University of Oxford, This research was supported by the Natural Environment Research Council through the Looking into the Continents from Space (LiCS) large grant (NE/K011006/1) and the Centre for the Observation and Modeling of Earthquakes, Volcanoes and Tectonics (COMET). M-P.D.’s contribution was supported by the CNES (DAT-S1 CNES-APR-180027).
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: Permafrost degradation; Freeze/thaw cycles; solifluction; InSAR time series; Northeast Tibe; [SDE.MCG]Environmental Sciences/Global Changes; [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology; Ice; permafrost
• Online Access: https://hal.science/hal-04494127; https://hal.science/hal-04494127/document; https://hal.science/hal-04494127/file/Daout_20_iceloss__2_.pdf; https://doi.org/10.1016/j.epsl.2020.116404

International audience InSAR time series of surface deformation from 16 yr of Envisat (2003-2011) and Sentinel-1 (2014-2019) ESA satellite radar measurements have been constructed to characterise spatial and temporal dynamics of ground deformation over an 80,000 km2 area in the permafrost of the northeastern Tibetan Plateau. The regional deformation maps encompass various types of periglacial landforms and show that seasonal thaw effects are controlled by the sediment type and local topography. High seasonal ground movements are concentrated on shallow slopes and poor-drainage areas in unconsolidated, frost-susceptible and fine-grained sediments within glacier outwash plains, braided stream plains, alluvial deposits or floodplains. Fast subsidence due to thaw settlement takes place during June/July while frost heave is intense during December/January when two-sided freezing of pore water under pressure causes prolonged ice segregation near the permafrost table. The analysis reveals pervasive subsidence of the ground of up to ∼2 cm/yr, and increasing by a factor of 2 to 5 from 2003 to today, in high-relief and well-drained areas. The findings suggest that seasonal thaw increasingly affects ice-rich layers at the permafrost table, as well as high-rates of widespread mass movements of non-consolidated sediments, the latter amplified by an increase of effects from frost heave/thaw settlement.