Status of glaciers and climate change of East Karakoram in early twenty-first century

Abstract

This study aims to assess the glaciers change status in Shyok basin, East Karakoram in terms of area and mass balance, and to ascertain if glaciers in this part of Karakoram also display similar anomaly like central or western counterparts. The spatio-temporal monitoring of glaciers during the time frame of 24 years (1990/2000/2014) suggests major percentage of stable glaciers and insignificant retreat in the total glaciated area. The percentage of retreating glaciers has increased after year 2000. Area change analysis of glaciers having size >1 km2 (569 glaciers) suggests the number of fluctuated glaciers have substantially increased i.e. overall 56% glaciers remained stable, 35% retreated and 9% advanced during 1990–2014. The geodetic based findings using SRTM-C (2000) and Cartosat-1 (2010/2011/2014) stereo-imageries for 201 glaciers suggest the mass loss at the rate of −0.10 ± 0.07 m w.e. a−1. To better apprehend the status of glaciers changes in the region, climatic studies using in-situ observations as well as reanalysis dataset (ERA-I) were also undertaken of past 30 years. Therefore, this study is also a maiden attempt to ascertain if along with Karakoram anomaly, a climatic anomaly exists in the Eastern parts of Karakoram or not. A long term field collected snow-meteorological data of East Karakoram region suggests overall warming trend in annual temperature and no trend for snowfall during 1985–2015. The statistically significant increased rates of warming and decreased snowfall after year 2000 support the spatial variations in glaciers of East Karakoram and marginal mass loss. The observations of the marginal mass loss along with warming temperatures indicate that no Karakoram or climatic anomaly is existent over the East Karakoram region. Our study further refutes the prevalence of the elevation-dependent warming (EDW) over East Karakoram region vis-à-vis North-West Himalayan ranges. The impact of hiatus in global warming was also not observed over studied region.