Russian geographers have found out how over three thousand glaciers of Caucasus, the Pamirs and Tien Shan mountain systems change.

Scientists from Institute of Geography (Russian Academy of Sciences) have presented results of their study of ice covering vast mountain territories. For that purpose they processed data of field experiments, carried out directly on glaciers, and applied original indirect calculating techniques for some parameters of the environment, not forgetting about data of aero-space surveys of high mountainous areas, performed by satellites and other space vehicles. “Glacier space monitoring” is performed within the “Uragan (Tornado)” programme, which currently takes place in Russian segment of International space station, as well as within the multinational “GLIMS” project, which analyses digital multi-channel images of areas, covered with ice with resolution of 15-30 meters, broadcasted to Earth by means of LANDSAT and TERRA satellites.

Researchers have paid careful attention not only to glacier size – its area and ice thickness – but also to other parameters, such as snow resources, estimating numerous inner and outer connections, direction and amount of moisture transfer, distribution of precipitation along vast mountain spaces – in other words, to all factors, responsible for glacier formation and existence.

In general, geography think tank mentions rapid decrease of glacier cover, which can possibly be explained by global climatic warming. Scientists consider current state of glaciers to be an extreme stage of their long-term evolution. Taking the Pamirs as an example, researchers showed that recent forty years resulted in general 8%-decrease in area of 683 glaciers, located in the water basin of the river Muksu – ice shrunk to 1817.1 square km from original 1956.6 square km.

Caucasus glaciers disappear even faster – melting caused loss of 16 per cent of their ice cover during recent 50 years. Caucasus glaciers started losing their ice in the end of the 19th century – large glaciers split to small ones, adding 181 new glaciers to ice cover of the mountain system, though reducing its area on 789.5 square km between 1881 and 1957. Glacier tongues showed average regression of 80-90 meters and significant reduction in ice thickness.

However, scientists also want to emphasize following optimistic conclusion of their research – some of their data reveal that not all Earth’s glaciers are reducing, for example, average annual weight balance of East Antarctic glaciers was positive during the last half of the 20th century, showing growing tendency during recent 35-40 years.

Russian explorer have analyzed samples of ice cores from wells, bored on Mount Elbrus, and found out that on heights of 4000 meters above sea level and higher Caucasus glaciers contain less alien chemical substances than samples of clear cloud water, collected above sub-Arctic Scandinavian regions. Content of sulfates and nitrates of anthropogenic origin was 4-5 times lower than that of high mountainous alpine snow cover.

Source:
    Pamirs - the roof of the world
    Science News

Kizilova Anna