This study describes the morphological and dynamic changes of Parkachik Glacier, Suru River valley, Ladakh Himalaya, India. We used medium-resolution satellite images; CORONA KH-4, Landsat and Sentinel-2A from 1971–2021, and field surveys between 2015 and 2021. In addition, we used the laminar flow-based Himalayan Glacier Thickness Mapper and provide results for recent margin fluctuations, surface ice velocity, ice thickness, and identified glacier-bed overdeepenings. The results revealed that overall the glacier retreated by −210.5 ± 80 m with an average rate of 4 ± 1 m a⁻¹ between 1971 and 2021. Whereas a field study suggested that the glacier retreat increased to −123 ± 72 m at an average rate of −20 ± 12 m a⁻¹ between 2015 and 2021. Surface ice velocity was estimated using COSI-Corr on the Landsat data. Surface ice velocity in the lower ablation zone was 45 ± 2 m a⁻¹ in 1999–2000 and 32 ± 1 m a⁻¹ in 2020–2021, thus reduced by 28%. Further, the maximum thickness of the glacier is estimated to be ~441 m in the accumulation zone, while for glacier tongue it is ~44 m. The simulation results suggest that if the glacier continues to retreat at a similar rate, three lakes of different dimensions may form in subglacial overdeepenings.

This paper aims to broadly understand the response of glaciers to thick and thin debris cover from one of the less explored regions (Zanskar) of the Himalaya. The present study is based on ground-based measurements (from 2015 to 2019), satellite data (since 1971), and available topographic maps (at a 1:50,000 scale). The study includes snout retreat, changes in equilibrium line altitude (ELA), surface elevation, and modeled mass balance of thick and thin debris-covered Pensilungpa (Suru River basin) and Durung-Drung (Doda River basin) glaciers in the western Indian Himalaya, Ladakh, for the past five decades. The Durung-Drung Glacier (DDG) receded ~−624 ± 547 m with an average rate of −12 ± 11 m a⁻¹ between 1971 and 2019. The frontal part of the DDG is broad (~2 km wide), which shows wide discrepancies in its retreat. Compared to DDG, the small and narrow snout of the Pensilungpa Glacier (PG) retreated −270.5 ± 27.5 m (1971 to 2019), with an average rate of −5.6 ± 0.57 m a⁻¹. Similarly, the four years (2015–2019) of field observations suggest that the retreat rate of PG and DDG is −6.7 ± 3 and −18 ± 15 m a⁻¹, and the rate of modeled glacier mass loss is −0.29 ± 0.3 and −0.3 ± 0.3 m w.e. a⁻¹, respectively. Furthermore, the ELA of the DDG and PG between 1971 and 2019 increased by ~59 ± 38 and ~23 ± 19 m, respectively. The change in the longitudinal profile of the glaciers along the centerline between 2000 and 2017 shows the DDG and PG lost ~17 and 15 m surface ice thickness. The change in debris cover plays a critical role in the glacier surface lowering, shrinkage, retreat, and mass balance. Hence, we quantitatively evaluated the influence of the debris cover on summer ablation and terminus recession on two different characteristic glaciers (DDG and PG) with its potential effect on the mass balance process (area-volume loss).

Glacial lakes dynamics has a concomitant impact over glacial retreat, mass change and glacial lake outburst floods (GLOFs) events. Recent warming led increase in glacial retreat at High-Mountain Asia (HMA) which has accelerated the formation of moraine-dammed glacial lakes; however, their relative potential for catastrophic events i.e., GLOF, are still a matter of detailed research. In the present study, the changes are assessed at the terminus position, glacier area and associated proglacial lake of Gepang Gath Glacier (GGGL), Chandra basin, western Himalaya, India, using multi-years satellite dataset of Landsat series (TM, ETM+ and OLI, 1989–2017). The results of glacial volume estimations using volume-area scaling method suggests ∼0.28 km³ of ice volume loss between 1989 and 2017. The glacier has retreated ∼846 m with an average rate of 30 m a⁻¹ and lost ∼0.73 ± 0.05 km² frontal area from 1989 to 2017. However, the glacier has not shown uniform retreat rate. Between 1989 and 2000 glacier retreat about ∼14 m a⁻¹ and the rate was increased gradually to ∼38 m a⁻¹ (2000–2009) and ∼50 m a⁻¹ (2015–2017). The calculated proglacial lake area has expanded ∼44 % and estimated equilibrium line altitude (ELA) rise was 54 ± 12 m, during the study period. The study explains that the continuous expansion of proglacial lake and ice loss can be dangerous to downstream region. It is concluded by underlining the importance of glacier-lake relationships to predict the glacial lake behavior and understand the probability of lake catastrophic events i.e., GLOF and associated hazards.