Recent recession and potential future lake formation on Drang Drung glacier, Zanskar Himalaya, as assessed with earth observation data and glacier modelling

Abstract

This study assessed the changes in the area, snout and proglacial lake formation for Drang Drung glacier located in Zanskar region of Jammu and Kashmir using earth observation data of 46 years from 1971 to 2017. In addition, ice thickness and formation of potential future lakes were modelled using a distributed model—GlabTop. Our analysis indicated that Drang Drung glacier shrunk by 13.84% from 1971 to 2017. Meteorological projections of temperature and precipitation over region were used to understand climatic changes over Drang Drung region. The snout of the glacier has retreated by 925 m since 1971 at the rate of 21.11 ma−1. However, the snout retreat radically accelerated since 2014 at 60 ma−1. Analysis of available satellite data suggested that the proglacial lake formed around 2014. The lake has expanded to 16.62 ha in 2017 amassing a water volume of 2.69 mi m3 with a potential peak discharge of 2667 m3 s−1. Based on GlabTop simulation, the mean thickness of the glacier is 155 m with the highest thickness of 311 m. Climate projections indicate that the temperatures would rise by over 4 °C by the end of this century with insignificant increase in precipitation. GlabTop simulations indicate formation of two huge lakes with areas of 97 and 47 ha in the lower ablation part of the glacier which could pose a risk to the incidence of glacial lake outburst flood in the near future.