Spatio-temporal Change of Glacier Surging and Glacier-dammed Lake Formation in Karakoram Pakistan

Glaciers in the northern part of Pakistan are the major source of water to the main river systems in Pakistan. These reservoirs of freshwater are under threat due to a continuous increase in the global mean temperature. The present study investigates two selected (Khordopin and Passu) glaciers surge and resultant induce glacier lakes and lake area change in terms of time and space. Observed temperature and precipitation data obtained from three high-altitude weather stations are also analyzed to examine the recent climate change in the region. The Khordopin glacier has shown an advancing behavior with an average surge of around 15–18 m/day for April–May 2017; it shows reduced velocity to 10 m/day during May–June 2017 as computed to the monthly Sentinel 2 and Landsat OLI images for the study area. During a field campaign, its velocity was recorded 2 m/day from 2 km above stream level of the glacier flow. However, the glacier shows different surge behaviors at different locations and altitudes. The Khordopin and the associated glacial lake show the best example of a surging glacier and formation of a Glacier dammed lake in the region. On the other hand, Passu Glacier indicates glacier retreating behavior. From the analysis of meteorological data (1995–2010), the maximum and minimum temperatures increase at a rate of 0.07 °C/year and 0.08 °C/year, respectively, while annual precipitation increases at 0.18 mm/year during the observational period. The MODIS snow data show an increasing trend in maximum snow-covered from 2000 onward, while the decreasing trend in minimum snow-covered from 2000 to 2008.