Inventory of rock glaciers in Himachal Himalaya, India using high-resolution Google Earth imagery

Abstract

Little information about the number, spatial distribution, and characteristics of rock glaciers in Himachal Himalaya is available. This information is crucial to assess the hydrological contribution of permafrost regimes and to understand its response to changing climate. Employing high-resolution satellite data freely accessible through Google Earth, the first comprehensive rock glacier inventory of Himachal Himalaya is presented in this work. The inventory reports 516 rock glaciers in the study area corresponding to an estimated area of 353 km2 of which 59% have glacier origin and 41% have talus origin. The frontal elevation of the lowest rock glacier in the Himachal Himalaya is 3052 m above sea level which was significantly low, whereas the highest rock glacier occurs at 5503 m above sea level. The mean minimum elevation of rock glaciers was 4484 m above sea level and the maximum was 4900 m above sea level. The majority of the rock glaciers have a northerly aspect (N, NE, NW) followed by westerly aspect signifying that slopes with lower potential incoming solar radiation favour the formation of rock glaciers. The mean annual surface temperature of the rock glaciers derived from Moderate Resolution Imaging Spectroradiometer (MODIS) Land surface temperature (LST) product (MOD11B3) was −1.5 °C, with glacier-derived rock glaciers having colder surfaces than talus-derived rock glaciers. The topographical and climatological parameters greatly influenced the formation and development of rock glaciers.