Annual cycle in flow of Ross Ice Shelf, Antarctica: contribution of variable basal melting

• Published in: Journal of Glaciology
• Main Authors: Klein, Emilie, Mosbeux, Cyrille, Bromirski, Peter, Padman, Laurie, Bock, Yehuda, Springer, Scott, Fricker, Helen
• Other Authors: Laboratoire de géologie de l'ENS (LGENS), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Institute of Geophysics and Planetary Physics San Diego (IGPP), Scripps Institution of Oceanography (SIO), University of California San Diego (UC San Diego), University of California-University of California-University of California San Diego (UC San Diego), University of California-University of California, Earth and Space Research, Corvallis, OR, USA (ESR), Earth and Space Research Institute Seattle (ESR)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: Antarctic glaciology; ice/ocean interactions; ice shelves; [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology; Antarctic; Austral; Ross Ice Shelf; The Antarctic; Antarc*; Antarctica; Ice Sheet; Ice Shelf; Ice Shelves; Journal of Glaciology
• Online Access: https://hal.archives-ouvertes.fr/hal-03033704; https://hal.archives-ouvertes.fr/hal-03033704/document; https://hal.archives-ouvertes.fr/hal-03033704/file/Klein_JOG_2020.pdf; https://doi.org/10.1017/jog.2020.61

International audience Ice shelves play a critical role in modulating dynamic loss of ice from the grounded portion of the Antarctic Ice Sheet and its contribution to sea-level rise. Measurements of ice-shelf motion provide insights into processes modifying buttressing. Here we investigate the effect of seasonal variability of basal melting on ice flow of Ross Ice Shelf. Velocities were measured from November 2015 to December 2016 at 12 GPS stations deployed from the ice front to 430 km upstream. The flow-parallel velocity anomaly at each station, relative to the annual mean, was small during early austral summer (November-January), negative during February-April, and positive during austral winter (May-September). The maximum velocity anomaly reached several metres per year at most stations. We used a 2-D ice-sheet model of the RIS and its grounded tributaries to explore the seasonal response of the ice sheet to time-varying basal melt rates. We find that melt-rate response to changes in summer upper-ocean heating near the ice front will affect the future flow of RIS and its tributary glaciers. However, modelled seasonal flow variations from increased summer basal melting near the ice front are much smaller than observed, suggesting that other as-yet-unidentified seasonal processes are currently dominant.