An imbalancing act: the delayed dynamic response of the Kaskawulsh Glacier to sustained mass loss

• Published in: Journal of Glaciology
• Main Authors: Young, Erik, Flowers, Gwenn, Berthier, Etienne, Latto, Rebecca
• Other Authors: Simon Fraser University (SFU.ca), Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales Toulouse (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2021
• Subjects: Glacier mass balance; ground-penetrating radar; ice and climate; melt-surface; mountain glaciers; [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology; Canada; Kaskawulsh Glacier; Yukon; glacier*; Journal of Glaciology
• Online Access: https://hal.archives-ouvertes.fr/hal-03361115; https://hal.archives-ouvertes.fr/hal-03361115/document; https://hal.archives-ouvertes.fr/hal-03361115/file/Young_et_al_JOG_2021.pdf; https://doi.org/10.1017/jog.2020.107

International audience The Kaskawulsh Glacier is an iconic outlet draining the icefields of the St. Elias Mountains in Yukon, Canada. We determine and attempt to interpret its catchment-wide mass budget since 2007. Using SPOT5/6/7 data we estimate a 2007-18 geodetic balance of −0.46 ± 0.17 m w.e. a −1. We then compute balance fluxes and observed ice fluxes at nine flux gates to examine the discrepancy between the climatic mass balance and internal mass redistribution by glacier flow. Balance fluxes are computed using a fully distributed mass-balance model driven by downscaled and bias-corrected climate-reanalysis data. Observed fluxes are calculated using NASA ITS_LIVE surface velocities and glacier cross-sectional areas derived from ice-penetrating radar data. We find the glacier is still in the early stages of dynamic adjustment to its mass imbalance. We estimate a committed terminus retreat of ∼23 km under the 2007-18 climate and a lower bound of 46 km 3 of committed ice loss, equivalent to ∼15% of the total glacier volume.