Documenting glacial changes between 1910, 1970, 1992 and 2010 in the T urgen M ountains, M ongolian A ltai, using repeat photographs, topographic maps, and satellite imagery

TheTurgenMountains lie in northwesternMongolia, roughly 80 km south of theRussian border. The area was visited in 1910 by aRoyalGeographicalSociety expedition led byDouglasCarruthers. The party undertook an extensive survey of the range and also documented the extent of the glaciers with photographs. One hundred years later, in summer 2010, aUS–Mongolian expedition retraced portions of the 1910 expedition. Camera locations were matched to the historical photographs and repeated photographs taken. In addition, the termini of the two main glacial lobes were surveyed byGPS. Analyses of field data, repeated photographs from 1910 and 2010, topographic maps from 1970, and satellite imagery from 1992 and 2010 were used to describe the changes in the glacial system. The results suggest that while the snow and ice volume on the summits appears to be intact, lower elevation glaciers show significant recession and ablation. From 1910 to 2010,WestTurgenGlacier receded byc. 600 m and down‐wasted byc. 70 m. This study successively demonstrates the utility of using historic expedition documents to extend the modern record of glacial change.