Surge-type glacier and investigated surface displacement using Remote Sensing

The Karakoram region contains a large number of surge-type glaciers, but few surging glaciers have been investigated by surface displacement and DEM differencing. The paper presents the surge dynamics of one unnamed glacier in Yarkand basin, of Karakoram region between 2000 and 2019 using satellite imagery (e.g., Landsat and Sentinel 2). Also, multiple high-resolution DEMs (e.g., HMA and Cartosat 1) were used to estimate mass transfer from the reservoir zone to the receiving zone. The DEM differencing exhibit maximum thickening of the lower receiving zone was ~190 ± 31 m whereas a maximum thinning of the upper reservoir zone was – 17 ± 31 m between 2018 and 2016. The receiving zone gained 256 ± 143 × 106 m3 ice mass between 2018 and 2011. The surface displacement was lower than 0.07 ± 0.02 m d- 1 in the quiescent phase between 2000 and 2011 and it reached to ~5 ± 0.3 m d- 1 in the active phase (autumn 2015). The glacier terminus retreated – 765 ± 89 m from 1978 to 2016 but advanced +681 ± 57 m during 2016–2019. This analysis indicate that the gradual increase in surface displacement about four years before the onset of the surge, long active phase (three years) and slow termination corroborate partially thermally controlled Svalbard-type surge.