On the relationship between local topography and small glacier change under climatic warming on Mt. Bogda, eastern Tian Shan, China

Abstract

Glacial features in the geological record provide essential clues about past behavior of climate. Of the numerous physical systems on earth, glaciers are one of most responsive to climate change, especially small glaciers, their direct marginal response taking only a few years or decades to be expressed. Accelerating recession of modern glaciers raises the issue of the climate's impact on water runoff. Data based on topographic maps and Advanced Spaceborne Thermal Emission and Radiometer (ASTER) imagery show the trends that are highly variable over time and within the region. An analysis of the local topographic settings of very small (<0.5 km 2 ) glaciers was conducted to investigate their influence on recent changes in these glaciers. Among 137 glaciers, 12 disappeared completely. The study reveals that glaciers situated in favorable locations had tiny relative area reduction, while those in less favorable settings generally had large area loss or even disappeared. It is suggested that most of the small glaciers studied have retreated as far as they are likely to under the climatic conditions of the late 20th century. Undoubtedly, the strong retreating of small glaciers exerts adverse effects on the hydrologic cycle and local socioeconomic development.

Topographic and geometric controls on glacier changes in the central Tien Shan, China, since the Little Ice Age

“…2). These ages are consistent with that of 412 ± 2 0 years BP dated using lichenometry (Chen, 1989) and those of 416± 146 and 428 ± 1 2 7 calibrated years BP based on accelerator mass spectrometry 14 C dating of inorganic carbonate coating from the same moraine (Yi and others, 2004; Li and others, 2011). These ages indicate that the fresh moraines close to modern glaciers were formed during the LIA in this area.…”

“…3b). The mean value is ~10° greater than the mean slope of the 488 glaciers in the eastern Himalaya (Racoviteanu and others, 2008), but similar to the mean slope (29.48) in the Bogeda range, eastern Tien Shan (Li and others, 2011). We divided the aspect of glaciers into eight 45° intervals.…”

“…In addition, glacier changes are affected by local topographic/geometric characteristics. For example, studies of mountain glaciers in northwestern China and the Himalaya suggest that small glaciers have changed more significantly than large ones in recent decades (Liu and others, 2003; Bhambri and others, 2011; Li and others, 2011). Statistical analysis of glaciers from the World Glacier Inventory () reveals that most glaciers in mid-high latitudes have poleward aspects due to limited solar radiation (Evans, 2006).…”

A Review on the Little Ice Age and Factors to Glacier Changes in the Tian Shan, Central Asia

“…Glaciers of different sizes are proven to have strong correlations with the rate of glacier changes, and small glaciers are undergoing stronger retreat compared to large-sized glaciers, e.g. [77][78][79][80]. The presence of many small glaciers today are formed due to the rapid disintegration of medium-sized glaciers and are likely to disappear if the warming trend of climate continues [80].…”

Monitoring glacial shrinkage using remote sensing and site-observation method on southern slope of Kalik Mountain, eastern Tian Shan, China

“…However, glacier distribution (Brenning and Trombotto, 2006;Evans, 2006), as well as area change of individual glacier (Li et al, 2011;Debeer and Sharp, 2009), is influenced by their local topographic settings and climatic conditions in regional scales. Small glaciers located in lower altitude lost more of their area or even completely disappeared.…”