Scientists from St. Petersburg State University, the Institute of Geology and Mineralogy of the Siberian Branch of the Russian Academy of Sciences and Altai State University have studied the size of the glaciers of the North Chui Ridge from the middle of the XIX century to the present day. It turned out that the area of glaciers has decreased by an average of two times and continues to shrink. The results of the study are published in the scientific journal Remote Sensing.

The Altai Mountains are one of the most important mountain systems in southern Siberia and Central Asia. It is not only the tourist center of Western Siberia, but also the most important geographical, geological, cultural and historical territory. A significant part of the Altai Mountains is covered by glaciers, which are mainly located on the North Chui Ridge. As part of a project supported by the Russian Science Foundation, St. Petersburg State University scientists are studying the North Chui Ridge, in particular the valley of the Maashey River. Studies have shown that the area of glaciers has significantly decreased over the past 150 years.

"We found that since the middle of the XIX century glaciers have shrunk more than twice — and more strongly than in other regions of Altai, and in the last decade the retreat of large glaciers has accelerated. If before 2010 the Bolshaya Maashey Glacier, where we conducted field research, shrank by 6-7 meters per year, then after 2010 its edge retreats by an average of 14 meters per year," said Dmitry Ganyushkin, professor of the Department of Physical Geography and Landscape Planning at St. Petersburg State University.

Geologists have applied a set of scientific methods to study the dynamics of glacier changes. In particular, the marks of the glacier boundaries, which were applied from the first half of the twentieth century, were studied. At the same time, geographers received and studied data on the dynamics of temperature and precipitation in this area. In addition, the authors of the study used satellite imagery data. Not only information from the last few years was found, but also data from 2000 and images from the middle of the last century taken by the American Corona reconnaissance satellite and recently discovered.

According to the scientists of St. Petersburg State University, the reduction of glaciers is an important factor in mountainous areas. It not only contributes to the expansion of the forest belt and the uplift of the vegetation border, but can also affect economic activity and even directly threaten people. Thus, the reduction of glaciers leads to a change in the temporary distribution of water in mountain rivers during the year. In addition, the melting of glaciers can trigger dangerous mechanisms associated with the activation of slope processes, erosion of loose rocks, which can cause mudslides, rock collapses or breakthroughs of reservoirs.

A similar breakthrough has already occurred on the territory of the North Chui Ridge in 2012, when, after prolonged heavy rains, a natural dam eroded and Lake Maashey was completely drained. As a result of the incident, no one was injured, but the lake, which previously attracted a large number of tourists, is no longer in this place, bridges were destroyed and logistics of the territory was difficult.

The study of Altai glaciers was carried out within the framework of the project "Changes in climate, glaciers and landscapes of Altai in the past, present and future as the basis of a model of adaptation of the population of the inland mountainous regions of Eurasia to climate-conditioned environmental changes", supported by a grant from the Russian National Science Foundation.

Information provided by the press service of St. Petersburg State University Information taken from the portal "Scientific Russia" ( /)

Photo source: / Alexander Kryazhev

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