Glacier Changes on the Pik Topografov Massif, East Sayan Range, Southeast Siberia, from Remote Sensing Data

Small mountain glaciers represent the most abundant class in many glaciarized areas around the world; however, less is known about their recent area changes under climatic variability of the last decades. The recent fluctuations of glaciers located in the inner parts of continents are the least studied. In this study we present the results of repeated mapping of seven small (<1.5 km(2)) glaciers located in a continental setting on the northern slope of the Pik Topografov massif, East Sayan Range, southeast Siberia. The multitemporal glacier inventory was derived from the late summer Landsat TM/ETM+ scenes acquired between 1986 and 2010. Glacier outlines were mapped with thresholded ratio (TM3/TM5) method. Topographic inventory parameters were measured from SRTM DEM. Glacier outlines of the Little Ice Age maximum (LIA, similar to 1850) were reconstructed from terminal moraines widely distributed around the glacier snouts. The results indicate a total ice area decrease from 8.1 km(2) in the LIA to 3.8 km(2) in 2010 (53%, 0.33% year(-1)). We revealed accelerated area shrinkage between 1991 and 2001 (almost two times higher than during the period 1986-2010), while between 2001 and 2010, the ice area did not change significantly. Overall, the glacier changes are consistent with the regional climatic trends (winter precipitation and summer temperature). Local topographic settings significantly impacted the glacier dynamics.