Стабильные изотопы 18O и D в ключевых компонентах водного стока и криолитозоны Центральной Якутии (Восточная Сибирь)

On the basis of about 430 analyses, the 18O and D compositions (%o) of atmospheric precipitation, ground ice, surface and inter-permafrost underground waters of cryogenic-aeolian landscapes of Central Yakutia (Eastern Siberia) are discussed. Precipitation compositions here demonstrate a large annual variation (from -6.12 to -45.0 % for δ18O, and from -72.1 to -350.1 % for δD), and they are described by the Local Meteoric Water Line according to the equation δD = 7.81518O - 1.57). In winter and in the process of spring melting, the snow storage is subjected to a significant evaporative fractionation, that is expressed by the equation δD = 6.85518O - 31.9. The heaviest and deuterium-depleted compositions (δ18O = -19.3 %, δD = -160.9, dexc = -6.7 %) are found in the last snow patches in early June. The lightest compositions similar to the present-day winter precipitation (snow) are characteristic of the polygonal wedge ices (PWI) of the Central Yakutia. The most lightweight (from -30 to -34 % for δ18O, and from 240 to 275% for δ D) were established to be typical for the ancient PWI, dated by the first half of the Late Pleistocene (MIS 3-4). Heavier compositions (δ18O = -27.2±1.4, δD = -215.8±8.5, dexc = 1.7±3.1 %) with obvious features of evaporative fractionation correspond to younger PWI (MIS 2-1). The heaviest compositions (δ18O = -12.2±0.7, δD = -99.2±4.7, dexc = -2.0±0.8 %) and high angular coefficients of approximating equations were determined in the investigated cave ices of sublimation origin, that implies the atmospheric origin of them. The current processes of evaporative fractionation are the most intensively reflected in the waters of aeolian lakes (δ18O = -11.8±3.5, δD = -120.2±18.4, dexc = -25.8±10.5 %), and the compositions are described by the regression equation 5D = 5.52 δ18O - 54.12 (R2 = 0.97). The phenomenal objects of the cryogenic-eolian landscapes of the Central Yakutia are high-debit underground sources. Among all other components of the water flows, composition of these sources is the most stable (δ18O = -21.6±0.8, δD = -172.6±5.1, dexc = 0.23±3.0 %). The regression of compositions of the largest underground source Bulus is approximated by the equation 5D = 6.31 δ18O - 36.7 (R2 = 0.78), that is indicative to significant evaporative fractionation and close relation with the aeolian lakes in the alimentation area.Особенности рельефа и строения криолитозоны Центральной Якутии связаны с широким распространением здесь позднечетвертичных супесчаных дюнных покровов. Они вмещают разветвлённые сети обводнённых межмерзлотных таликов, гидравлически связанных эоловых озёр, подземных источников, фрагменты едомных отложений с мощными ледяными жилами, а также наледи. На основе выборки более чем из 430 определений обсуждается разнообразие состава стабильных изотопов (18O и D) перечисленных компонентов водного стока

Изотопный состав и регионы-источники зимних осадков в Надымской низменности

According to the forecast of IPCC (Intergovernmental Panel of the Climate Change), an increase in precipitation is expected in this century in the Arctic. The main reason is intensification of evaporation from waters of the Arctic Ocean opening due to the intensive melting of sea ice. It is supposed that these changes will be most severe in winters in the Arctic regions, which are subject to significant anthropogenic load. In this respect, the intensively developed Nadym Lowland may be considered as a promising area for researches. The results of our study showed that the circulation conditions (primarily cyclones coming from the North Atlantic under the Eastern (E) circulation form of the G.Ya. Vangenheim–A.A. Girs classification) significantly influence on the isotopic composition of precipitation in this region. Thus, in the cold period of 2016–2017, the isotopic composition of precipitation changed for δ18О by 21 ‰, and for δD by 167 ‰ (weighted average values δ18О = −22.3 ‰, δD = −172.6 ‰, and dexc = 5.6 ‰). The use of the dew point temperature at the moment of precipitation in the calculations of the isotopic-temperature dependences allows obtaining the following coupling equation: δ18О = 0.67Tdp − 15.2 (R2 = 0.67). On the basis of the joint analysis of synoptic, trajectory and isotopic data, the main regions-sources of atmospheric moisture, precipitated in the Nadym Lowland during the cold period of 2016–2017, were determined. The major contributions were made by the Atlantic Ocean (35.7%), the North Atlantic Ocean and the Arctic Ocean (30.4%), and the Black Sea-Caspian region (20%). The last one is characterized by the most weighted isotopic composition. Inland source regions have contributed the least to precipitation (slightly larger 10%), and their lightweight isotopic composition is related to cryogenic fractionation.В результате совместного анализа синоптических, траекторных и изотопных данных определены основные регионы‑источники поступления атмосферной влаги, выпавшей в виде осадков в Надымской низменности. Наибольший вклад вносит Атлантический океан (35,7%), меньше – северная часть Атлантического океана и Северный Ледовитый океан (30,4%), а также Черноморско‑Каспийский регион (20%) и внутриконтинентальные регионы (немногим более 10%)

Изотопный состав и палиноспектры атмосферных осадков и краевых частей ледника Корумду (Северо-Чуйский хребет, Горный Алтай)

The article presents results of study of the isotope composition and pollen spectra of atmospheric precipitation and ice taken from marginal parts of Korumdu Glacier (North-Chu Ridge, the Altai Mountains). The study was aimed at identification of sources and ways of precipitation into the nival-glacial region of Altai. Investigation of the isotope composition of ice taken from the tongue of the Korumdu Glacier and summer precipitation in its basin has shown that here the isotope concentrations are much smaller than similar ones of the cold Belukha Glacier. The last one is located near the Korumdu Glacier. This difference can be explained by the fact that main source of moisture forming layers of relatively warm Korumdu Glacier is precipitation of the cold season while accumulation on the cold Belukha Glacier proceeds during the whole year mainly due to the most heavy precipitation of warm (from March to November) season. Analysis of the isotope composition and the air mass trajectories on the day of July 16, 2013 allowed conclusion that the air masses started their way in the Baltic Sea region and moved mainly along middle latitudes. On this way they underwent insignificant isotope fractionation. Synoptic analysis had shown that the main reason of precipitation on the area under investigation was a front of occlusion over the Altai. In addition, results of palynological analysis of precipitation allow identification sources of pollen in this region. With high probability we can assume that on that day the main sources of pollen in Altai precipitation are as follows: the Naryan-Mar area for Scots pine (Pinus sylvestris) pollen, tundra zones of the East European Plain for alder (Alnaster sp.) pollen and the steppe regions of Kazakhstan, and the West Altai for pollen grains – the dominant component of the pollen spectrum.Исследование изотопного состава льда языка ледника Корумду и летних осадков, выпадавших в его бассейне, показало, что изотопный состав льда изучаемого ледника значительно облегчён как относительно осадков, так и относительно ледовых слоёв расположенного недалеко от Корумду холодного ледника Белуха. Такое отличие, в первую очередь, можно объяснить тем, что основной источник влаги при формировании слоёв тёплого ледника Корумду – атмосферные осадки холодного периода года, в то время как аккумуляция на холодном леднике Белуха происходит весь год, в основном за счёт наиболее обильных осадков тёплого (с марта по ноябрь) периода года. Результаты изотопного и споровопыльцевого анализа атмосферных осадков конкретных единичных событий и данные об обратных траекториях движения воздушных масс (модель HYSPLIT) позволяют получать объективную информацию о генезисе приходящей в изучаемый регион атмосферной влаги, а также определять источники поступления и оценивать дальность переноса пыльцы тех или иных растений на исследуемую территорию. Так, по данным изотопного состава осадков, выпавших в горноледниковом бассейне ледника Корумду 16 июля 2013 г., и траектории движения воздушных масс, принёсших эти осадки на территорию Алтая, сделан вывод, что воздушные массы, начавшие свой путь в Балтике, продвигались преимущественно по умеренным широтам и подвергались незначительному изотопному фракционированию. Анализ синоптической ситуации позволяет утверждать, что основной причиной выпадения осадков на изучаемой территории стало формирование фронта окклюзии над Алтаем. Результаты спорово-пыльцевого анализа осадков дополнительно дают возможность идентифицировать источники поступления пыльцы в изучаемый регион. Например, с большой вероятностью можно предположить, что в это время район г. Нарьян-Мар служил основным источником поступления пыльцы сосны обыкновенной (Pinus sylvestris) в изучаемый ледниковый бассейн. При этом пыльца злаковых – доминирующего компонента пыльцевого спектра – может быть как местной, так и принесённой с севера степных районов Казахстана и запада Алтайского края, а пыльца ольховника (Alnaster sp.) в атмосферных осадках 16 июля 2013 г., вероятно, принесена из лесотундровой и тундровой зон Восточно-Европейской равнины

МИКРОЭЛЕМЕНТНЫЙ И ИЗОТОПНЫЙ СОСТАВ СНЕЖНОГО ПОКРОВА КАТУНСКОГО ПРИРОДНОГО БИОСФЕРНОГО ЗАПОВЕДНИКА (РЕСПУБЛИКА АЛТАЙ)

The present-day regional level of various trace elements contents together with characteristics of isotopic composition was for the first time estimated in seasonal snow cover of Altai. As a background territory, the State Nature Biosphere reserve «Katunsky» had been chosen. This reserve is included into the World network of biosphere reserves under the UNESCO Program «Man and biosphere». The route snow survey had been carried out at the end of February 2014 since this is a period of maximum snow accumulation. The snow survey involved evaluation of snow storages, stratigraphic analysis of the snow cover, and layer-by-layer snow sampling for analysis of its trace element and isotopic compositions. Isotopic and stratigraphic analysis of visually selected layers of the snow cover revealed substantial variation in the values of δ18O and δD (the maximum difference between layers was 120.1 and 15.3 ‰, respectively), whiledexc changed within the range from 5.6 to 16.6 ‰. The weighted-mean values of the snowpack isotopic composition are the following: δ18O = −24.9 and δD = −188.9 ‰, and the isotopic ratio of oxygen and deuterium is described by the equation δD = 8,3δ18О + 18.9. The analysis of microelement composition of the snow samples made with the use of the crustal enrichment factor (EFc) and correlation matrix allowed determination of elements (Ba, Be, V, Co, Li, Mn, Ni, Sr, Tl, Th, U и Cs) released into the atmosphere above the territory under investigation mainly with particles of fly ash, in which the ratio of elements corresponds to the regional natural sources – soils and underlying rocks. It was shown that the main part of elements Ag, As, Bi, Cu, Mo, Sb, Zn come preferably from anthropogenic sources which are non-ferrous metallurgy enterprises of East Kazakhstan and pits of operating and abandoned mines of Rudny Altai.По наблюдениям зимой 2013/14 г. оценён современный фоновый уровень содержания широкого спектра микроэлементов в сезонном снежном покрове Алтая и изучены особенности изменения его изотопного состава. С помощью расчётных коэффициентов «обогащения» определены элементы (Ba, Be, V, Co, Li, Mn, Ni, Sr, Tl, Th, U и Cs), поступающие в основном в составе золы уноса при сжигании углей и имеющие схожие с природными источниками соотношения данных металлов, тогда как основные источники поступления Ag, As, Bi, Cu, Mo, Sb и Zn – это предприятия цветной металлургии и шламоотвалы горнодобывающих карьеров Рудного Алтая

Isotopic composition and source regions of winter precipitation in the Nadym Lowland

According to the forecast of IPCC (Intergovernmental Panel of the Climate Change), an increase in precipitation is expected in this century in the Arctic. The main reason is intensification of evaporation from waters of the Arctic Ocean opening due to the intensive melting of sea ice. It is supposed that these changes will be most severe in winters in the Arctic regions, which are subject to significant anthropogenic load. In this respect, the intensively developed Nadym Lowland may be considered as a promising area for researches. The results of our study showed that the circulation conditions (primarily cyclones coming from the North Atlantic under the Eastern (E) circulation form of the G.Ya. Vangenheim–A.A. Girs classification) significantly influence on the isotopic composition of precipitation in this region. Thus, in the cold period of 2016–2017, the isotopic composition of precipitation changed for δ18О by 21 ‰, and for δD by 167 ‰ (weighted average values δ18О = −22.3 ‰, δD = −172.6 ‰, and dexc = 5.6 ‰). The use of the dew point temperature at the moment of precipitation in the calculations of the isotopic-temperature dependences allows obtaining the following coupling equation: δ18О = 0.67Tdp − 15.2 (R2 = 0.67). On the basis of the joint analysis of synoptic, trajectory and isotopic data, the main regions-sources of atmospheric moisture, precipitated in the Nadym Lowland during the cold period of 2016–2017, were determined. The major contributions were made by the Atlantic Ocean (35.7%), the North Atlantic Ocean and the Arctic Ocean (30.4%), and the Black Sea-Caspian region (20%). The last one is characterized by the most weighted isotopic composition. Inland source regions have contributed the least to precipitation (slightly larger 10%), and their lightweight isotopic composition is related to cryogenic fractionation

Stable isotopes of 18O and D in key components of water flows and the permafrost zone of Central Yakutia (Eastern Siberia)

On the basis of about 430 analyses, the 18O and D compositions (%o) of atmospheric precipitation, ground ice, surface and inter-permafrost underground waters of cryogenic-aeolian landscapes of Central Yakutia (Eastern Siberia) are discussed. Precipitation compositions here demonstrate a large annual variation (from -6.12 to -45.0 % for δ18O, and from -72.1 to -350.1 % for δD), and they are described by the Local Meteoric Water Line according to the equation δD = 7.81518O - 1.57). In winter and in the process of spring melting, the snow storage is subjected to a significant evaporative fractionation, that is expressed by the equation δD = 6.85518O - 31.9. The heaviest and deuterium-depleted compositions (δ18O = -19.3 %, δD = -160.9, dexc = -6.7 %) are found in the last snow patches in early June. The lightest compositions similar to the present-day winter precipitation (snow) are characteristic of the polygonal wedge ices (PWI) of the Central Yakutia. The most lightweight (from -30 to -34 % for δ18O, and from 240 to 275% for δ D) were established to be typical for the ancient PWI, dated by the first half of the Late Pleistocene (MIS 3-4). Heavier compositions (δ18O = -27.2±1.4, δD = -215.8±8.5, dexc = 1.7±3.1 %) with obvious features of evaporative fractionation correspond to younger PWI (MIS 2-1). The heaviest compositions (δ18O = -12.2±0.7, δD = -99.2±4.7, dexc = -2.0±0.8 %) and high angular coefficients of approximating equations were determined in the investigated cave ices of sublimation origin, that implies the atmospheric origin of them. The current processes of evaporative fractionation are the most intensively reflected in the waters of aeolian lakes (δ18O = -11.8±3.5, δD = -120.2±18.4, dexc = -25.8±10.5 %), and the compositions are described by the regression equation 5D = 5.52 δ18O - 54.12 (R2 = 0.97). The phenomenal objects of the cryogenic-eolian landscapes of the Central Yakutia are high-debit underground sources. Among all other components of the water flows, composition of these sources is the most stable (δ18O = -21.6±0.8, δD = -172.6±5.1, dexc = 0.23±3.0 %). The regression of compositions of the largest underground source Bulus is approximated by the equation 5D = 6.31 δ18O - 36.7 (R2 = 0.78), that is indicative to significant evaporative fractionation and close relation with the aeolian lakes in the alimentation area

Isotopic composition and pollen spectra of precipitation and ice at the edge part of Korumdu Glacier (North Chu ridge, Altai Mountains)

The article presents results of study of the isotope composition and pollen spectra of atmospheric precipitation and ice taken from marginal parts of Korumdu Glacier (North-Chu Ridge, the Altai Mountains). The study was aimed at identification of sources and ways of precipitation into the nival-glacial region of Altai. Investigation of the isotope composition of ice taken from the tongue of the Korumdu Glacier and summer precipitation in its basin has shown that here the isotope concentrations are much smaller than similar ones of the cold Belukha Glacier. The last one is located near the Korumdu Glacier. This difference can be explained by the fact that main source of moisture forming layers of relatively warm Korumdu Glacier is precipitation of the cold season while accumulation on the cold Belukha Glacier proceeds during the whole year mainly due to the most heavy precipitation of warm (from March to November) season. Analysis of the isotope composition and the air mass trajectories on the day of July 16, 2013 allowed conclusion that the air masses started their way in the Baltic Sea region and moved mainly along middle latitudes. On this way they underwent insignificant isotope fractionation. Synoptic analysis had shown that the main reason of precipitation on the area under investigation was a front of occlusion over the Altai. In addition, results of palynological analysis of precipitation allow identification sources of pollen in this region. With high probability we can assume that on that day the main sources of pollen in Altai precipitation are as follows: the Naryan-Mar area for Scots pine (Pinus sylvestris) pollen, tundra zones of the East European Plain for alder (Alnaster sp.) pollen and the steppe regions of Kazakhstan, and the West Altai for pollen grains – the dominant component of the pollen spectrum

MICROELEMENT AND STABLE ISOTOPIC COMPOSITION OF SNOWPACK IN THE KATUNSKY BIOSPHERE RESERVE (ALTAI REPUBLIC)

The present-day regional level of various trace elements contents together with characteristics of isotopic composition was for the first time estimated in seasonal snow cover of Altai. As a background territory, the State Nature Biosphere reserve «Katunsky» had been chosen. This reserve is included into the World network of biosphere reserves under the UNESCO Program «Man and biosphere». The route snow survey had been carried out at the end of February 2014 since this is a period of maximum snow accumulation. The snow survey involved evaluation of snow storages, stratigraphic analysis of the snow cover, and layer-by-layer snow sampling for analysis of its trace element and isotopic compositions. Isotopic and stratigraphic analysis of visually selected layers of the snow cover revealed substantial variation in the values of δ18O and δD (the maximum difference between layers was 120.1 and 15.3 ‰, respectively), whiledexc changed within the range from 5.6 to 16.6 ‰. The weighted-mean values of the snowpack isotopic composition are the following: δ18O = −24.9 and δD = −188.9 ‰, and the isotopic ratio of oxygen and deuterium is described by the equation δD = 8,3δ18О + 18.9. The analysis of microelement composition of the snow samples made with the use of the crustal enrichment factor (EFc) and correlation matrix allowed determination of elements (Ba, Be, V, Co, Li, Mn, Ni, Sr, Tl, Th, U и Cs) released into the atmosphere above the territory under investigation mainly with particles of fly ash, in which the ratio of elements corresponds to the regional natural sources – soils and underlying rocks. It was shown that the main part of elements Ag, As, Bi, Cu, Mo, Sb, Zn come preferably from anthropogenic sources which are non-ferrous metallurgy enterprises of East Kazakhstan and pits of operating and abandoned mines of Rudny Altai