Stable isotope geochemistry of massive ice

The monograph summarises stable-isotope research on massive ice in the Russian and North American Arctic, and includes the latest understanding of massive-ice formation. A new classification of massive-ice complexes is proposed, encompassing the range and variability of massive ice. It distinguishes two new categories of massive-ice complexes: homogeneous massive-ice complexes have a similar structure, properties and genesis throughout, whereas heterogeneous massive-ice complexes vary spatially (in their structure and properties) and genetically within a locality and consist of two or more homogeneous massive-ice bodies. Analysis of pollen and spores in massive ice from Subarctic regions and from ice and snow cover of Arctic ice caps assists with interpretation of the origin of massive ice. Radiocarbon ages of massive ice and host sediments are considered together with isotope values of heavy oxygen and deuterium from massive ice plotted at a uniform scale in order to assist interpretation and correlation of the ice. The monograph is intended for both undergraduates and graduate students, and will assist researchers in geocryology, glaciology, geomorphology, Quaternary geology and palaeoclimatology in understanding of the origin and palaeoenvironmental significance of massive ice

Реконструкция среднеянварской температуры воздуха в голоцене в низовьях реки Колымы

The object of study is ice wedges at 10 sites in the lower Kolyma River. The Holocene age of ice wedges is determined on the basis of radiocarbon dating of the enclosing sediments and location of ice wedges in alases, floodplains and lacustrine-paludal basins. The analysis of radiocarbon dates has shown that formation of alases with ice wedges began in early Greenlandian stage of Holocene (the oldest dates are 11 and 10.8 cal ka BP). The most active alas development and syngenetic ice wedge growth occurred since the second half of the Greenlandian stage till the middle-late Northgrippian stage of the Holocene, most of the available 14C dates fall in the range from 9.5 to 4.2 cal ka BP. Accumulation of the floodplain deposits of the Kolyma River occurred mainly during the Meghalayan stage, according to obtained 14C dates from 2.5 to 1.9 cal ka BP. Oxygen isotope data of studied ice wedges show that for the Holocene ice wedges the range of δ18O is about 4 ‰ (from –28 to –23.7 ‰) and for the modern ice veinlets– about 5 ‰ (from –28.1 to –23 ‰). Water of meteoric origin was the main source for ice wedge formation, however, for ice wedges on the floodplains some participation of surface (river) water is not excluded. Based on the refined equation of the ratio between ice wedge isotope composition and mean January air temperature, paleotemperatures for three key periods of the Holocene were calculated. It was established that mean January air temperature during the Holocene varied in the approximately same range: from –40.7 to –33.8 °С during the Greenlandian stage, from –38.6 to –33.3 °С during the Northgrippian stage and from –41.5 to –33 °С during the Meghalayan stage. This most likely indicates the stability of winter climatic conditions in the north of Yakutia during the Holocene, determined by the influence of Siberian anticyclone.Реконструкция среднеянварской температуры в низовьях р. Колыма для трёх ключевых периодов голоцена, выполненная на основе данных изотопного состава повторно-жильных льдов, показала, что среднеянварская температура воздуха в течение голоцена варьировала незначительно, средние значения для более тёплых и более суровых зим составляли −33 и −41 °C соответственно. Показана стабильность зимних климатических условий на севере Якутии в голоцене, определяемая влиянием сибирского антициклона

Изотопная индикация источника воды для образования ледоминерального ядра торфяных миграционных бугров пучения

Isotopic characteristics of ice cores of peat mounds (palsa) are considered. The distribution of the values of δ18O, δ2H, dexc and ratios δ18O–δ2H within the palza ice lense is associated with freezing in a closed or open system, and this allows finding the source of water for the ice formation. The use of computational modeling of the distribution of the values of δ18О and δ2Н during the ice formation in a closed system and the selection of the calculated parameters, performed in such a way that the actual values in the ice are described, show the initial isotopic characteristics of the moisture from which the ice was formed. The subject of investigation is the isotopic composition of segregated ice in the upper part of the ice core of a palsa near the Yeletsky settlement. Ice samples were obtained by drilling with a hand-held electric drill. In its upper part, the core is composed of frozen peat and loam. The source of water for the formation of segregated ice from this palsa was the atmospheric moisture with isotopic characteristics equal, on average, to: δ2Н = −106.7, δ18О = −15.3 and dexc = 15.7 ‰. These values correspond to the current atmospheric precipitation in the vicinity of the Amderma settlement. The water of the nearest bog did not serve as a source of water for the ice formation. The same conclusion, fully confirmed by the application of the calculated approach, was obtained for the hummocky massif of the Yukon (Canada). The calculation did show that the water from which the ice of the Canadian palsa was formed was a mixture of local atmospheric precipitation (80%) and the boggy waters of the peat plateau (20%). The presence of the last water is a possible indication to re-formation of mounds, when evaporated water from bog could participate in ice core formation.Рассмотрены изотопные характеристики ледоминерального ядра торфяных миграционных бугров пучения. На основе распределения значений δ18О, δ2Н, dexc и соотношений δ18O–δ2Н, а также выполненного моделирования льдообразования в закрытой системе сделаны выводы о происхождении воды, которая стала источником для льда бугров пучения типа пальза

Изотопная индикация условий образования ледяных ядер булгунняхов (пинго)

Te isotopic characteristics of the pingo ice cores are considered. Te distribution of δ18O and δ2H values, dexc, δ18O–δ2H and δ2H–d exc relationships, and the simulation of the distribution of δ18O and δ2H values during the ice formation in a closed system, allowed drawing conclusion about the hydrological conditions and stages of the ice core growth. All pingos (Pestsovoye, Weather, Pingo-20) were formed in draining lake basins in the course of freezing of closed taliks. It is established that the water, which served as a source for the formation of the ice core, was subjected to evaporation still before the ice formation. According to our estimates, the water from which the ice of the Pestsovoye pingo was formed was heavier in values of δ18O and δ2H by 3.9 and 29.7‰, respectively, than the current average annual precipitation in the region. Similarly, for the ice of the core of the Pingo Weather it is 2.9 and 14.5‰, and 5.1 and 27.7‰ for the Pingo-20, respectively. In the ice cores of all considered pingos there is an ice formed in a closed system: in Pingo-20 it is a pure injection ice, while in the Pestsovoye and the Weser ones – the injected-segregated ice. Te frost mounds Pestsovoe and Weser grew under changing hydrological conditions: one part of the ice was formed when there was a free flow of water to the freezing front (open system); the other one – when the water-saturated lenses of the closed talik were frozen (closed system). Te isotopic composition of ice being formed under conditions of a closed system reflects isotopic depletion during freezing and ice formation according to the Rayleigh model. It is expressed in a successive decrease in the values of δ18O and δ2H from the frst portions of ice to the last ones as the freezing continued. Te contrast values of δ18O and δ2H in different parts of the ice being formed in the closed system may be used as an additional tool to identify direction of freezing. In a closed system, the last portions of ice have the greater contrast of the isotope values as compared to the frst portions.Рассмотрено распределение значений δ18О, δ2Н и dexc в ледяных ядрах инъекционных бугров пучения (булгуннях, пинго). Установлено, что булгуннях Песцовое (Тазовский п-ов), пинго Уэзер (залив Прудо, Аляска) и пинго-20 на Аляске сформировались при образовании льда из воды осушающихся озёр, которая до начала пучения подверглась испарению. Контрастность значений δ18О в разных частях ледяного ядра может быть использована как дополнительный инструмент для установления направления промерзания

Реконструкция среднеянварской температуры воздуха в раннем голоцене на восточном побережье Чукотки

The investigation is concerned with the Early Holocene syngenetic massive wedge ice exposed in the outcrop of a polygonal peatland in the upper part of the third marine terrace near Lorino settlement on the eastern coast of Chukotka. Based on the obtained radiocarbon dates of peat, it was found that the formation of a peatland in the area began about 14–13 cal ka BP, at the end of the Younger Dryas, while the termination of the active stage of peat accumulation was dated to about 10–9 cal ka BP. The beginning of peat accumulation at the end of the Younger Dryas, earlier the officially accepted limit of the lower boundary of the Holocene (11.7 cal ka BP), and the termination of its formation by the middle of the Greenlandian Holocene period is not a rare phenomenon in Russian permafrost zone, although it is traditionally assumed that the most active formation of peatlands has been going on during the thermal maximum in the middle of the Holocene. The age inversions noted in the peat vertical profiles are the most likely indicative of the processes of re-deposition of ancient organic material due to erosion by water of the third marine terrace sediments and the separation of the allochthonous peat. During the period from 2015 to 2021, six fragments of peatland exposures with the ice wedges were studied. Analysis of the obtained data on the content of stable oxygen isotopes in the ice show that δ18О values vary within the range from –15.5 to –18‰. These values are in good agreement with the data for Early Holocene ice wedges earlier obtained in other areas of the eastern coast of Chukotka (Anadyr town, Uelen settlement), where authors report the δ18O values from –16 to –19.4‰. This suggests that the ice wedge growth as well as the peat accumulation were the most active in Early Holocene. The highest δ18О values (from –13.1 to –16.8‰) were obtained for the modern ice veinlets. The ratio δ2 H–δ18O in the ice wedges, in general, is indicative of a good preservation of isotope signature of winter precipitation. It has been found that approximate mean January air temperature in the Early Greenlandian period varied from –23 to –27°С, which is, on average, 3°С below than the present-day ones.Формирование полигонального торфяника на поверхности третьей морской террасы в районе села Лорино на восточном побережье Чукотки началось в конце позднего дриаса и завершилось в начале голоцена. Среднеянварская температура воздуха в первой половине гренландского периода голоцена, реконструированная на основе данных изотопного состава повторно-жильных льдов, возраст которых не моложе 10–9 тыс. кал. лет назад, в среднем на 3°С ниже современной и варьировала от –23 до –27°С

Изотопно-кислородный состав льда ледника № 30 в горах Сунтар-Хаята

The object of research is the mountain-valley glacier № 30, located in the central part of the Suntar-Khayatа Ridge – one of the largest centers of modern glaciation of the North-East of Russia. This glacier had been chosen due to lamination of ice on its surface, providing successive sampling of increasingly young ice upward the glacier slope. At the end of August 2013, surface ice of the glacier was sampled within the altitude range 2060–2510, an age of this ice here was estimated to be about 500 years old. Variations of δ18О values in the glacier ice amounted about 5.5‰: from −20.2 to −25.9‰ that is numerically consistent with isotopic values for the neighboring glaciers № 29 and 31. No essential relation between the ice isotopic composition and altitude, age or the change of the ice granularity was found. Absence of high-altitude isotope effect is explained by the fact that preciptation on the glacier № 30 falls at the same level of condensation as well as by intensive infiltration-congelation ice formation and fixation in the firn and snow cover of a part of the meltwater coming from higher and steeper areas on gently sloping sites of the glacier. The δ18О values of ice from glacier № 30 are rather «heavy» for glaciers being formed in severe climate conditions with average January temperature of −28 °C. According to Dansgaard's dependence δ18Оprecipitation – t °Cair the winter snow on the glacier № 30 should be hypothetically characterized by the δ18О values from −30 to −40‰ which are typical ones for the winter snow in Siberia. Oxygen isotope values of the ice show insignificant contribution of winter snow into formation of the glacier and prevalence of spring-autumn snowfalls. No definite trend of changes in the glacier alimentation and the ice-formation process was found for the last 500 years.Рассмотрен изотопно-кислородный состав поверхностного льда ледника №  30 в горах Сунтар- Хаята, отобранного в 2013  г. Вариации δ18О во льду ледника №  30 составили около 5,5‰. При этом не отмечено существенного изменения изотопного состава льда с высотой или с его возрастом. Сопоставлен изотопный состав льда ледника № 30 и зимнего снега, выпадающего в разных районах Сибири. На основании полученных изотопных данных показано, что питание ледника происходит преимущественно за счёт весенне-осенних осадков при незначительном участии зимнего снега

Microbial and Geochemical Evidence of Permafrost Formation at Mamontova Gora and Syrdakh, Central Yakutia

Biotracers marking the geologic history and permafrost evolution in Central Yakutia, including Yedoma Ice Complex (IC) deposits, were identified in a multiproxy analysis of water chemistry, isotopic signatures, and microbial datasets. The key study sections were the Mamontova Gora and Syrdakh exposures, well covered in the literature. In the Mamontova Gora section, two distinct IC strata with massive ice wedges were described and sampled, the upper and lower IC strata, while previously published studies focused only on the lower IC horizon. Our results suggest that these two IC horizons differ in water origin of wedge ice and in their cryogenic evolution, evidenced by the differences in their chemistry, water isotopic signatures and the microbial community compositions. Microbial community similarity between ground ice and host deposits is shown to be a proxy for syngenetic deposition and freezing. High community similarity indicates syngenetic formation of ice wedges and host deposits of the lower IC horizon at the Mamontova Gora exposure. The upper IC horizon in this exposure has much lower similarity metrics between ice wedge and host sediments, and we suggest epigenetic ice wedge development in this stratum. We found a certain correspondence between the water origin and the degree of evaporative transformation in ice wedges and the microbial community composition, notably, the presence of Chloroflexia bacteria, represented by Gitt-GS-136 and KD4-96 classes. These bacteria are absent at the ice wedges of lower IC stratum at Mamontova Gora originating from snowmelt, but are abundant in the Syrdakh ice wedges, where the meltwater underwent evaporative isotopical fractionation. Minor evaporative transformation of water in the upper IC horizon of Mamontova Gora, whose ice wedges formed by meltwater that was additionally fractionated corresponds with moderate abundance of these classes in its bacterial community. © Copyright © 2021 Cherbunina, Karaevskaya, Vasil’chuk, Tananaev, Shmelev, Budantseva, Merkel, Rakitin, Mardanov, Brouchkov and Bulat.We thank Samsonova Vera, Karzhavin Vladimir, Pankov Alexander, Andreevskaya Maya and Alexander Osipov for their for their invaluable assistance in field work

Изотопный состав кислорода снежно-фирновой толщи на Восточной вершине Эльбруса

The isotopic composition of oxygen of the snow-and-firn and snow thickness on the Eastern peak of Elbrus had been studied. In 2006-2008, a number of snow samples were taken in the near-peak area of Elbrus to analyze the isotopic composition of them. The drilling was performed at the crater of the Eastern peak in 2006 (64 samples) while in 2017 the samples were taken from snow pit (25 samples). Another core to a depth of 23.8 m was extracted at the Western Plateau (118 samples) for the purpose to compare local 518О values with samples from the Eastern peak. The δ18О values in the snow-and-firn thickness from the crater of the Eastern peak vary from -6.8 to -19.41 %o with the average value of -12.61 %o. It was revealed that snow layers with extremely low values of δ18О (down to -30 %) found on the eastern slope were absent on the western plateau. The loss of part of the annual isotope precipitation signal due to the winter extra light horizons could be caused by two reasons: wind drift of the freshly deposited snow, as well as the absence of part of the winter snowfalls with isotope-light precipitation at altitudes higher 5300 m. Seasonal variations of δ18О values, equal to 12 % and found in the snow-and-firn thickness on the Eastern peak, indicate that formation of the isotopic characteristics of snow is determined here by the equilibrium Rayleigh condensation and this is associated with the annual amplitude of the air temperature by a coefficient of 0.6 %o/°C. In the isotopic record obtained on the Western plateau of Elbrus, the relationship of values δ18О with the condensation temperature may be disturbed due to the frequent change of the main moisture-bearing air masses. This leads to significantly different δ18О values in precipitation at the same temperatures (the connection of seasonal δ18О values with the annual amplitude of air temperature varies from 0.3 to 1.12 %о/°С).Установлены сезонные вариации значений δ18О в снежно-фирновой толще на Восточной вершине Эльбруса от -6,8 до -19,41 %о при среднем значении -12,61 %о. В отличие от Западного плато здесь отсутствуют слои снега с экстремально низкими значениями δ18О. Потеря части годового изотопного сигнала осадков за счёт зимних экстра лёгких горизонтов связана с ветровым сносом уже отложенного снега и отсутствием части зимних снегопадов с изотопно лёгкими осадками на высотах более 5300 м

Изотопный состав снежного покрова Байкальского региона

Deuterium and oxygen‑18 are standard water tracers which are widely used to investigate hydrological processes and to trace the moisture sources. In this study, we collected bulk samples taken from the snow cover in the Baikal region distributed from the city Yakutsk to the Lake Baikal. Ulan-Ude had been chosen as a key site to study the snow cover in more details. It has been shown that during the winter season δ18O values in Ulan-Ude reach −39‰ that is typical for the inland air masses of meridional or western transport. The aim of this study was to describe the spatial variability of concentrations of the isotopes deuterium (2H) and oxygen‑18 (18O) in the snow cover.Стабильные изотопы водорода и кислорода – природные трассеры гидрологического цикла, которые используются в исследованиях гидрологических процессов и для нахождения источника влаги. В статье приводятся данные по снежному покрову Трансбайкальского региона от г. Якутск до озера Байкал. Улан-Удэ был выбран в качестве ключевого участка для более детального изучения снежного покрова. Показано, что в зимний период значения δ18O снега в г. Улан-Удэ достигают −39‰, что типично для внутриконтинентальных воздушных масс – результатов меридионального и западного переноса. Цель статьи – описать пространственную изменчивость содержания стабильных изотопов водорода и кислорода в снежном покрове

Recent advances in paleoclimatological studies of Arctic wedge‐ and pore‐ice stable‐water isotope records

Late Pleistocene and Holocene ground ice are common throughout the Arctic. Some forms of relict ground ice preserve local meteoric water, and their stable oxygen‐ and hydrogen‐isotope ratios can be used to reconstruct past air temperatures. In this paper, we review the formation and sampling of two forms of relict ground ice—wedge ice and pore ice—and recent (2010–2019) advances in paleoclimatological studies of ground‐ice stable isotope records in the Arctic. Recent advances are attributed to better chronological constraints and refined understandings of the systematics and seasonality of relict wedge ice and pore ice. A rich network of ice‐wedge records has emerged, primarily from the Siberian Arctic, whereas pore‐ice records are less common. The ice‐wedge network depicts a robust pattern of late Pleistocene cooling, and remarkably similar temperature depressions during Marine Isotope Stages 3 and 2. Very high‐resolution wedge‐ and pore‐ice stable isotope chronologies have been established recently and used to reconstruct winter and summer climate histories and to assess seasonal dependencies in insolation‐forced climate. Reports of ancient (>125 ka BP) ground ice demonstrate its long‐term persistence, and its potential to expand our knowledge of Quaternary climate dynamics in the terrestrial Arctic