No 2 (2023)
Articles
Anomalously light geological complex on the watershed plain of the Yano-Indigir lowland
Abstract
The research method is a purposeful petrophysical interpretation of the gravitational field. The object under study appeared during prospecting geological and geophysical work as a hindrance to the solution of the main geological problem. Its density is 1 g/cm3, the height of the sole is 35 m, the area is 1420 km2, the volume is 20 km3. The object is defined as an abnormally light Ice Complex (ALIC). The revealed density is explained by peat-ice performance. In ALIC, a near-surface lenticular-layered formation ice has been uncovered, the structure of which indicates the generation of the mass of the complex ahead of sedimentation. The gravimetric data, the landscape and the details of the ALIC structure are interconnected and make up the first — the most complete view of the complex at the moment. The main elements of the presentation are the three phases of the development of the complex. The first is classical, generally accepted for polygonal—vein structures, the second differs from the classical one by the absence of frost-breaking cracking, the third is the growth of formation ice. The qualitative difference of the thermophysical components of the cryolithozone of the territory is given, which made it possible to introduce several concepts concerning the generation of peat-ice mass ALIC. Such as: heat dissipation capacity of the middle layer, stabilization of the zero isotherm at the petrophysical boundary; conditions for the beginning of the growth of lenticular-layered ice; accelerated lateral segregation growth of powerful ice veins; constancy of the thermal resistance of the cryolithozone. On the basis of these concepts, models of the development of the second and third phases of ALIC are compiled, and a view on the theory of the formation of cover glaciers is formed, which follows from the model of the third phase. The novelty of the research consists: in identifying a unique petrophysical object, in defining this object as ALIC, in identifying an ice massif on the territory of ALIC, in presenting the development of the complex as a sequence of three phases, in compiling models of the second and third phases of ALIC and in an original approach to the formation of cover glaciers.
Arctic and Antarctica. 2023;(2):1-33
1-33
Yedoma. Part 2. Annals of geocryological research, especially radiocarbon dating and the stable-isotopes studies in the first decade of the XXI century
Abstract
The first decade of the 21st century in the study of yedoma marked by the widespread use of AMS radiocarbon dating on microinclusions extracted directly from the ice wedge. These studies, together with a detailed study of stable isotope composition, were carried out at Lomonosov Moscow State University (Yu. Vasil'chuk and A. Vasil'chuk) on yedoma sections of Western Siberia, the lower Kolyma, Central Yakutia, together with specialists in the radiocarbon dating: J. van der Plicht, J.-Ch. Kim, H. Jungner, L.Sulerzhitsky. Isotope study of Yedoma sections on the right bank of the Yenisei Bay was begun (A.Vasiliev, E.Gusev, I.Streletskaya and others). During this period, active isotope and radiocarbon studies of yedoma began by the participants of the Russian-German expedition (A.Andreev, A.Chizhov, A. Derevyagin, G.Grosse, H.-W.Hubberten, L. Schirrmeister, S. Wetterich etc.) in the Anzhu Islands, the Lena Delta, and Arctic coast of Western Yakutia. In Chukotka, yedoma was studied by researches of the Anadyr station (A.Kotov). Researchers from the University of Fairbanks (M.Kanevsky, Yu.Shur, H.French, M. Bray and others) continued to study the Fox Tunnel as well as northern Alaska yedoma. Radiocarbon dating, the study of mammoth fauna, and stable isotopes were started by Canadian scientists (C. Burn, D.Froese, G. Zazula and others) on the Yukon yedoma. The study of Paleolithic sites in the yedoma sections were started of the Yana River and the New Siberian Islands (V. Pitulko, E. Pavlova etc.)
Arctic and Antarctica. 2023;(2):34-87
34-87
Assessment of the impact of the formation of water resources and the quality of surface waters of the Lena River basin
Abstract
Ongoing active development of natural resources, changing climatic conditions (including permafrost melting) In Eastern Siberia, it is necessary to control changes in the ecological state of the environment, one of which is surface water. The Roshydromet system has established and successfully operates a network of regime observations of the state and pollution of surface waters of the Russian Federation, ensuring the unity of measurement of the content of major pollutants in water according to uniform methods certified in accordance with the requirements of regulatory documents of the Russian Federation and international standards. In this paper, the formation of the quality of the surface waters of the Lena River basin under conditions of non–stationary climatic processes on the one hand and the anthropogenic component on the other is considered. Based on the analysis of statistically processed long–term data (2011-2021) obtained by the state monitoring network of Roshydromet, an assessment of the water quality of the Lena River and its major tributaries - the Vitim, Olekma, Aldan, Vilyu rivers is given. The spatio-temporal distribution of characteristic pollutants in the water of the rivers of the basin has been studied: organic substances (according to BPK5 and COD), phenols, petroleum products, iron, copper and zinc compounds. It was found that in the conditions of the Arctic climate, the seasonal distribution of organic substances in surface waters was insignificant. The presence of heavy metal compounds in the water of the Lena River basin water bodies is mainly due to anthropogenic sources of pollution. In the long-term plan, the water of the rivers of the Lena River basin was assessed as the 3rd satisfactory quality class.
Arctic and Antarctica. 2023;(2):88-101
88-101
Peculiarities of Interannual Variability of Sea Ice Area in the Northern Hemisphere
Abstract
The research has been made on the basis of an array of ice data for the maximums and minimums seasonal distribution of sea ice in the Northern Hemisphere. The probability range for the appearance of positive differences after the negative ones in March is greater than in September, and conversely. During the periods of minimum (March) and maximum (September) interannual changes, after positive differences with an increase in the number of differences in the group, the values of subsequent changes increase. There is an increase in the probability of a one sign occurrence interannual difference with an increase in the group of another sign previous differences. For the probability of zero differences (absence of variability), there is an increase in both the probability of zero values and the number of previous zero differences. The results indicate the presence of a stabilization mechanism in the stochastic interannual variability of the sea ice area, which is confirmed by an increase in the probability of the appearance of a one sign and the number of previous differences of another sign in the group. An increase in the probability of zero values with an increase in the number of previous zero differences confirms the presence of geographical areas in which there are no interannual changes in the area of sea ice.
Arctic and Antarctica. 2023;(2):102-114
102-114
Radial differentiation of chemical composition of cryogenic soils in the Chara river valley, north of Transbaikalia
Abstract
The subject of the study is the content of iron compounds and their radial differentiation in the profiles of cryogenic soils of the Chara River valley (Transbaikalia). The studied soils belong to post-pyrogenic permafrost gleyzems, the depths of the seasonal active‐layer of these soils are from 34 to 44 cm. Macronutrient concentrations, with the exception of Si, rarely exceed 5.0%, while the silicon content reaches 24.3%. Si is also characterized by removal from the upper part of soil profiles and accumulation in permafrost soil horizons. The highest concentrations are characteristic in the O horizons (Mg – 4.8 and Ca – 1.5 mg/kg) for a significant part of the macroelements. The trace elements, Sr and Zr are distributed vary contrastingly (from 5.0 to 29.7 and from 5.6 to 47.1 mg/kg). Values of the R coefficient from 0.3 to 0.9 indicate the initial stage of post-pyrogenic restoration of soil properties, and the active accumulation of Mg, Ca, Ti, Fe, Sr, and other elements in the upper part of oxidized-gley permafrost gleyzem observed in the profile is a sign of active restoration. The soils contain about 3.4% iron, which more than 60–75% is the silicate group of compounds (Feс). The moisture content of soils and the prevailing reducing environmental conditions contribute to the formation of monotonous distributions in their profiles, and in soils without signs of stable hydromorphism, permafrost horizons contain almost 2 times more Feox and Feextr.
Arctic and Antarctica. 2023;(2):115-128
115-128