Present Glaciers of Tavan Bogd Massif in the Altai Mountains, Central Asia, and Their Changes since the Little Ice Age

Abstract

The Tavan Bogd mountains (of which, the main peak, Khuiten Uul, reaches 4374 m a.s.l.) are situated in the central part of the Altai mountain system, in the territories of Russia, Mongolia and China. The massif is the largest glacierized area of Altai. The purposes of this study were to provide a full description of the scale and structure of the modern glacierized area of the Tavan Bogd massif, to reconstruct the glaciers of the Little Ice Age (LIA), to estimate the extent of the glaciers in 1968, and to determine the main glacial trends, and their causes, from the peak of the LIA. This work was based on the results of long-term field studies and analysis of satellite and aerial data. At the peak of the LIA, Tavan Bogd glaciation comprised 243 glaciers with a total area of 353.4 km2. From interpretation of Corona images, by 1968 the number of glaciers had decreased to 236, with a total area of 242 km2. In 2010, there were 225 glaciers with a total area of 201 km2. Thus, since the peak of the LIA, the glacierized area of the Tavan Bogd mountains decreased by 43%, which is somewhat less than for neighboring glacial centers (i.e., Ikh-Turgen, Tsambagarav, Tsengel-Khairkhan and Mongun-Taiga mountains). The probable causes are higher altitude and the predominance of larger glaciers resistant to warming. Accordingly, the smallest decline in Tavan Bogd occurred in the basins of the Tsagan-Gol (31.7%) and Sangadyr (36.4%) rivers where the largest glaciers are located. In contrast, on the lower periphery of the massif, where small glaciers predominate, the relative reduction was large (74–79%). In terms of general retreat trends, large valley glaciers retreated faster in 1968–1977 and after 2010. During the 1990s, the retreat was slow. After 2010, glacial retreat was rapid. The retreat of glaciers in the last 50–60 years was caused by a trend decrease in precipitation until the mid-1970s, and a sharp warming in the 1990s and early 2000s.

Spatio‐temporal occurrence and sensitivity to livestock husbandry of Pallas's cat in the Mongolian Altai

“…For the assessment across the 4 study areas, we considered all livestock, humans, and dogs as a single category, while for the focal area assessment, we considered small-and large-sized livestock separately. Parameters include elevation and distance to herders' tents or houses (i.e., ger) indicate that this area is suboptimal for this felid, likely because it is generally higher in elevation and has more extensive glacial and snow cover relative to the other areas (Ganyushkin et al 2018). The Pallas's cat appears to prefer areas that are steep, with natural vegetation and higher occurrence of prey, matching the high habitat and dietary specialization known for this species (Ross et al 2019a, Chimed et al 2021, Greenspan and Giordano 2021.…”

“…The moderate occupancy and very low detectability we estimated are broadly consistent with the presumed low density of this species (Ross et al 2012, Anile et al 2021), while the proportion of sites used on sites sampled is comparable with that of Chimed et al (2021). The significantly lower occupancy in Tavan Bogd may indicate that this area is suboptimal for this felid, likely because it is generally higher in elevation and has more extensive glacial and snow cover relative to the other areas (Ganyushkin et al 2018). The Pallas's cat appears to prefer areas that are steep, with natural vegetation and higher occurrence of prey, matching the high habitat and dietary specialization known for this species (Ross et al 2019 a , Chimed et al 2021, Greenspan and Giordano 2021).…”

Glacier Recession in Altay Mountains after the LIA Maximum

“…In our past publications, we reconstructed in detail the LIA glaciers of different glacial centers of Altai and their gradual reduction [50,[74][75][76][77]. The first generalization of our data on LIA reconstructions and subsequent reduction of glaciers was made by us for the arid regions of Altai (533 contemporary glaciers with the total area 313.4 km 2 , 450 LIA glaciers with the total area 635.6 km 2 ).…”

“…For such cases we used indicators defined by Loibl et al [36]: active ice indicators are "smooth" debris surface, linear flow structures, and constrained tributaries; dead ice indicators are rugged debris surface, melting ponds, unconstrained tributaries, and pioneer plants. We added two more diagnostic signs: for the massifs of of dead ice it is typical when the water flows into tunnels and its exits from other tunnels down the slope; the active glacial edge is marked by marginal flows that join at the lowest point of the glacier [50]. All these indicators work well, with the exception of pioneer plants, which, due to the dry climate of the central and eastern parts of Altai, are absent near the glaciers in those areas and appear only on the surface of inactive rock glaciers.…”

“…Furthermore, we used high-resolution images and compared interpretation results with in situ field observations. For Mongun-Taiga mountain range, we created interpretation standards [58], which we used first for Tavan Bogd massif [50] and subsequently in all other areas studied. A characteristic property of the study area favorable for visual interpretation includes the persistence of glacial topographic features associated with climate aridity, low erosion rates, low rates of biological processes, and poor development of periglacial vegetation cover.…”