Surface velocities and calving flux of the Academy of Sciences Ice Cap, Severnaya Zemlya

• Published in: Espacio Tiempo y Forma. Serie VI, Geografía
• Main Authors: P. Sánchez-Gámez, F. Navarro J., J. Dowdeswell A., E. De Andrés
• Other Authors: This study has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 727890 and from Agencia Estatal de Investigación under grant CTM2017-84441-R of the Spanish Estate Plan for R & D. The radio-echo sounding campaign was funded by grants GR3/9958 and GST/02/2195 to JAD from the UK Natural Environment Research Council. Copernicus Sentinel data 2016–2017 were processed by ESA.
• Format: Article in Journal/Newspaper
• Language: English
• Published: IGRAS 2020
• Subjects: Arctic;calving flux;glacier calving;ice cap;ice surface velocity;Severnaya Zemlya; айсберговый сток;Арктика;ледниковый купол;отёл ледников;поверхностная скорость движения ледника;Северная Земля; Arctic; Severnaya Zemlya; Annals of Glaciology; Antarctic and Alpine Research; Ice cap; Polar Research; Tidewater; Арктика
• Online Access: https://ice-snow.igras.ru/jour/article/view/779; https://doi.org/10.31857/S2076673420010020

We have determined the ice-surface velocities of the Academy of Sciences Ice Cap, Severnaya Zemlya, Russian Arctic, during the period November 2016 – November 2017, using intensity offset-tracking of Sentinel-1 synthetic-aperture radar images. We used the average of 54 pairs of weekly velocities (with both images in each pair separated by a12-day period) to estimate the mean annual ice discharge from the ice cap. We got an average ice discharge for 2016–2017 of 1,93±0,12 Gt a−1, which is equivalent to −0,35±0,02 m w.e. a−1 over the whole area of the ice cap. The difference from an estimate of ~1,4 Gt a−1 for 2003–2009 can be attributed to the initiation of ice-stream flow in Basin BC sometime between 2002 and 2016. Since the front position changes between both periods have been negligible, ice discharge is equivalent to calving flux. We compare our results for calving flux with those of previous studies and analyse the possible drivers of the changes observed along the last three decades. Since these changes do not appear to have responded to environmental changes, we conclude that the observed changes are likely driven by the intrinsic characteristics of the ice cap governing tidewater glacier dynamics. По 54 парам космических снимков Sentinel‐1, сделанных с ноября 2016 г. по ноябрь 2017 г., определены скорости движения ледникового купола Академии Наук на Северной Земле. На этой основе оценён среднегодовой расход льда в море этого купола (1,93±0,12 Гт/год), установлены основные пути стока льда, проведено сравнение с прежними оценками.