Glacier fluctuation in northern and High Asia: historical and methods perspective

Abstract

Glaciers in Asia occupy nowadays much smaller extents than those of the Pleistocene but they still play an important role in alpine ecosystems (e.g., Shahgedanova 2002). Glaciers also pose hazards to society and infrastructure, with avalanches and glacial lake outburst floods being the most destructive of glacier-related natural events (Richardson and Reynolds 2000; Janský et al. 2010; Nie et al. 2013; Wang and Zhang 2014). Since the end of the Little Ice Age (LIA), glaciers have been retreating almost everywhere around the world, and this process has dramatically accelerated during the recent decades (Fig. 1; WGMS 2013). However, individual glaciers are behaving differently and some have advanced while most have been in retreat (IPCC 2013; Yao et al. 2012). Mountain glaciers are sensitive indicators of climate change (e.g., Dyurgerov and Meier 2000; Haeberli et al. 2004) and to fully understand the connection between changing climate and glacier fluctuations, all the variables of the glacier mass balance need to be assessed at the local and regional scale (Dowdeswell et al. 1997; Oerlemans 2005). One of the regions where information about glacier changes is still scarce is northern and High Asia (Fig. 1), largely because glaciers of the region are located relatively far from human settlements and some have only been found after the 1940s. For example, Ivanov et al. (2015) have provided the first inventory of glaciers in the Barguzinsky Ridge east of Lake Baikal, Russia, in this issue. At the same time, continental glaciers of northern and High Asia are located far from the main sources of moisture and are thus sensitive to climate change (Fujita 2008; Kaser et al. 2010). In this issue, we have collected information about glaciers situated along a southwestnortheast transect from 77 E, 32 N (the Western Himalaya, India) to 128 E 65 N (the Orulgan Range, Russia; Fig. 2) and fed from different sources of moisture (the North Atlantic, the Arctic and the Indo-Pacific air masses). Because glaciers in our focus area belong to different climate systems, their systematic study across the whole region has the potential not only to assess the climate change at local and regional scales but also to reveal climate change patterns at a larger, continental scale. The papers of this issue cover a variety of glacier-related topics (methods studies, glacier inventories, current glacier dynamics, and paleo-reconstructions), and are based on a range of data, such as satellite imagery, synoptic maps, biogeochemical proxies from proglacial lake bottom sediments and meltwater streams, pollen and oxygen isotope records from snow-ice cores, and high-resolution seismic reflection data.