The effect of light-absorbing particles on the deglaciation of glaciers in the polar and mountainous territories

Cryoconite is determined as dark, unconsolidated sediments that appears on the glaciers surface. They play a role in the degradation of snow and ice cover in polar regions and high mountain glaciers. In the Central Caucasus, there is current active processes of degradation of glaciers mainly due to the precense of cryocinites. The biochemical properties of cryoconites that form on the surface of the Garabashi and Shkhelda glaciers have been studied. Together with the cryoconites studied, selected periglacial soils and mudflows materials in the high-mountainous part of the Baksan Gorge of Kabardino-Balkaria (Central Caucasus) were studied. The data obtained showed that cryoconites, sampled from different glaciers exhibit different levels of enzymatic activities. The samples taken from the Shkhelda glacier did not show evidentactivity of the studied enzymes. Contrary, in the first sample of cryoconite taken from the surface of the Garabashi glacier, a very low level of invertase activity and a weak catalase activity were revealed. The second sample, taken from the vertical cracks of the Garabashi glacier, showed high activity of urease, medium catalase and very weak - dehydrogenase. The studied periglacial soils exhibit different enzyme activities. The enzymes are most active in the surface layers of the studied soils, and within the vertical profile the activity decreases. The calculated total relative enzymatic activity of the soils showed that the mountain meadow soil has the highest activity, and the mountain forest meadow soil has the least activity. Different results were also obtained in samples taken from soil-like bodies formed as a result of mudflow slope event. In superficially vegetation covered mudflow sample a weak activity of hydrolytic enzymes was found, while in a sample without vegetation, activity was not manifested for any of the studied enzymes.