Estimation of Surface Ice Velocity of Durung Drung Glacier, Western Himalaya using COSI-Corr from Landsat images

Abstract

Glaciers all over the world have been experiencing recession at varying rates. Alterations in glacial retreat, volume, and mass have direct implications for sea level rise and have implications for the overall health of glaciers. Measuring the surface ice velocity of glaciers presents challenges due to the rugged terrain and harsh climate at high altitudes, making field observations difficult. This study aims to address these challenges by focusing on the calculation of the surface ice velocity of the Durung Drung glacier in Zanskar Valley, Ladakh. Landsat- 7 & 8 panchromatic bands with a resolution of 15 m were used in conjunction with the COSI-Corr module of ENVI image processing software to derive surface ice velocity. The method involved the crosscorrelation of Landsat images from 1999/2000 and 2019/2020. The COSI-Corr module used in this study provided three key outputs: east–west displacement, north–south displacement, and signal-to-noise ratio. These outputs are essential for understanding the movement of the glacier and evaluating the quality of the image correlation. The results indicate that the surface velocity of Durung Drung glacier was 71 ± 6.1 m yr⁻¹ in 1999/2000, which increased (by ∼ 50 %) to 140 ± 7.4 m yr⁻¹ in 2019/2020. An increasing trend in velocity manifests the rising trend in temperature in the western Himalaya. Analysis of CRU TS4 gridded data reveals an increase in temperature while precipitation decreased during 1976–2020. The study recommends that the annual variations in surface ice velocity are a consequence of temperature fluctuations that influence the availability of meltwater.