Permafrost landscapes and conditions of sites with the activation of cryogenic processes in the lower reaches of the Lena River

The cryogenic landscapes and conditions of sites with activization of cryogenic processes in the lower basin area of the Lena River were research from July 20 to August 11, 2017 within the initiative grant project of the Russian Geographical Society "The floating university on the Lena River". During implementation of the forwarding program of the Floating university on the Lena River have been met and three fresh exposures with the wedge ice are for the first time surveyed: in the delta of Lena on the island of Samoylovsky, on sites of terraces of Lena around the Govorovsky rift and near the mouth of the creek Semekit, its right inflow. Cryogenic textures of the containing deposits and contacts of veins testify to their syngenesis. Characteristic of all ice bodies its wedge-shaped form and an existence of elementary veins allowing to carry them to the wedge ice. The wedge having several sprouts met. In general the deposits of ice complex on Semekit and Govorovo sites opened in 2017 are the proof of their existence also on other sites of distribution of lake-and-alluvial and lake-and-marsh deposits. Increase of permafrost temperature is noted near Zhigansk in comparison with its values characteristic of Northern taiga landscapes in the second half of the XX century. At the same time in 2017 her decrease concerning values of previous year was observed. Data on landscape differentiation of seasonal thawing layer which can be used as a reference point when monitoring his dynamics are obtained. Conditions for action of thermokarst process and wedge ice destroying are very favorable on all basin of the Lena River from Yakutsk to its delta.

«Плавучий университет на реке Лене», Floating University on the Lena River, cryogenic landscapes, perennially frozen grounds, ice complex, ice wedge, Sangar, Zhigansk, Semekit, Dzhardzhan, Govorovo, Samoylovsky Island, Tiksi

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