Ice and Snow (E-Journal) / Лёд и Снег
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Подвижки ледников Памира в 2020 году
Get PDFEvery year, about ten glaciers in the Western Pamirs are in the active stage of movement. The time from the beginning of the movement of kinematic waves along the glacier to the full completion of the pulsation takes, as a rule, 1– 2 years, and in some cases lasts up to 5 years. Activity of the Pamir glaciers in 2020 is discussed in this paper, and we suppose that some pulsations are still in progress in the following years. Data from a number of automatic satellite instruments were used for the analysis, but mainly these were obtained from the International Space Station. In 2020, 10 glaciers in the basins of the Surkhob, Muksu, Seldara, Kyzylsu and Vanch rivers became more active, and in some cases surged. Similar dynamic instability of glaciers was also characteristic for the preceding four years. At present, several major surges are taking place in the Western Pamirs; the Byrs, Vali, Lenin, and Medvezhy glaciers started the active phase of their developments. Therefore, it is necessary to study them by field methods and continue permanent monitoring of them from automatic satellites and the International Space Station.Ежегодно в активной стадии подвижек на Западном Памире находятся не менее 10 ледников. Время от начала движения по леднику кинематических волн до полного завершения пульсации занимает, как правило, 1–2 года, а в отдельных случаях продолжается до 5 лет. В статье исследуется активность памирских ледников в 2020 г. и высказываются предположения о продолжении некоторых пульсаций в последующие годы. Для анализа использованы данные ряда автоматических космических аппаратов, но главным образом материалы съёмок с Международной космической станции. В 2020 г. отмечена активизация и в ряде случаев подвижки 10 ледников в бассейнах рек Сурхоб, Муксу, Сельдара, Кузылсу и Ванч; подобная динамическая нестабильность ледников характерна и для предыдущих четырёх лет. В настоящее время происходит несколько крупных подвижек. Ледники Бырс, Вали, Ленина и Медвежий вступили в активную фазу своего развития, поэтому необходимо изучать их полевыми методами и продолжать их постоянный мониторинг с автоматических космических аппаратов и МКС
Влияние специфического режима снежных отложений на вечномёрзлыe основания в городах криолитозоны (на примере Норильского региона)
Get PDFWith increasing snowfalls and rising winter temperatures in the Arctic regions of Russia (against the background of almost the same summer values), the role of solid precipitation in the formation of the temperature and humidity regimes of seasonally thawed and upper horizons of permafrost grounds becomes extremely important. No regular observations of snow accumulation in built-up areas were conducted in the Arctic settlements. This article presents for the first time the results of snow measurements in urbanized areas of the Norilsk region, and assesses the warming effect of snow cover on the permafrost grounds and foundations. The problems that arise during the mechanical redistribution of snow are identified. In some areas the thickness of the snow cover (near the city of Norilsk) by the end of March can reach 200 cm; in February, the average monthly value for the last 15 years amounts 69 cm, and in the city the height of snow dumps ranges from 2 to 5 m. The warming effect of snow cover on the permafrost layer enhances as the snow height increases from 0 to 2–2.5 m, and then remains unchanged. Large masses of snow existing for many decades in almost the same places (together with the snow drifts of the air from the ventilated subfields) result in the development of degradation tendencies within the permafrost. A slight temperature rise was noted in grounds under 30–40% of the operated objects (as compared with the design values), which causes deformation of the structures.Впервые проведены масштабные съёмки снегоотвалов на застроенных территориях в Норильске – крупнейшем городе в криолитозоне. Исследованы характер снегоотложения около объектов различной этажности, заносимость продухов холодных проветриваемых подполий в городской среде, оценено влияние снега в урбанизированной среде на температурный режим и несущую способность вмороженных фундаментов. 30–35% объектов инфраструктуры в районах города деформированы, одна из причин этого – условия снегонакопления в городах
Сокращение оледенения гор Сунтар-Хаята с середины XX века по 2018 год
Get PDFNew data on the state of the Suntar-Khayata Mountains glaciers in 2018 are presented and changes in the area of glaciers in the second half of the 20th and early 21st centuries are estimated. In 2018, the glaciation of the Suntar-Khayata Mountains was represented by 251 glaciers with a total area of about 133±10 km2. Among the morphological types in this region, the corrie and corrie-hanging glaciers predominate. The largest areas are occupied by valley and compound valley glaciers. The main part (82.7%) of the total area of glaciers is concentrated in the altitude range of 2200–2600 m. The changes in the glaciation area were analyzed over three periods: 1) from 1944–1947 to 2018; 2) from 1944–1947 to 2003; and 3) from 2003 to 2018. During the first one, the area of the glaciers registered in the Glacier Inventory of the USSR decreased from 199 to 132±10 km2, that is, by 67 km2 (33.6%). Of these, 28 km2 was lost in the period from 1944–1947 to 2003, and another 39 km2 in 2003–2018. By 2018, the largest reduction of the area occurred in small glaciers with an area of less than 0.1 km2 (more than 80%), the smallest – in large glaciers with an area exceeding 2 km2 (less than 21%). The glaciers with western aspect were the most reduced (39.9%), and with south–western aspect – the least (25.0%). As compared to the previous period, the significant increase in the rate of the area reduction was found in 2003–2018 – from 0.24% to 1.52% per year. At the beginning of the 21st century, the activation of the process of disintegration of glaciers into smaller fragments was recorded. Thus, the average size of the studied glaciers decreased from 1.03 km2 in 1944–1947 to 0.88 km2 in 2003 and to 0.59 km2 in 2018. The increase in the rate of the area reduction in the Suntar-Khayata Mountains noted in the early 21st century agrees with a stable positive anomaly of summer air temperatures observed from 2007 to 2018. The mean summer air temperature during this period was 12.2 °C, which was by 1 °C higher its average value for 1981– 2010; in 2008 and 2009, the difference reached 2 °C. In combination with the ongoing decrease in winter precipitation, this may be one of the main reasons for the increase in the rate of glacier reductionПриведены данные о морфометрических, морфологических и высотных характеристиках оледенения гор Сунтар-Хаята в 2018 г. Оценены изменения оледенения за три временных периода: c 1944–1947 по 2018 г., c 1944–1947 по 2003 г., с 2003 по 2018 г. Установлено существенное увеличение средней скорости сокращения площади ледников в 2003–2018 гг. по сравнению с периодом c 1944–1947 по 2003 г. В начале XXI в. зафиксирована активизация процесса распада ледников на фрагменты меньшего размера
Строение снежно-ледовых перемычек прорывных озёр полуострова Брокнес (оазис Холмы Ларсеманн, Восточная Антарктида) по данным георадиолокации
Get PDFDuring the summer field season of the 65th Russian Antarctic Expedition a research aimed at studying the structure of the snow-ice dams of the Lakes Progress and Discussion (Larsemann Hills, East Antarctica), which are characterized with annual outburst floods, was carried out. Survey was performed using groundpenetrating radar sounding complemented with noncore drilling and analysis of the aerial photo data acquired with unmanned aerial vehicle during the last field seasons. The results show that location of the waterways, which occur during the outbursts of the both lakes, does not change significantly year in year out and fits a linear depression in basement topography under the dam and a following flexure of the ice layer. During the winter period, the opened channels are being filled with snow, and thereby a natural soſtened zone is being formed. Further outburst flood propagates mainly within this zone. Monitoring survey of the snowi-ce dam of the Progress Lake during the summer period showed that destruction of the dam does not happen rapidly when the outburst takes place, but begins a few weeks before it with gradual filtration within the snow layer.Приведены результаты изучения строения снежно-ледовых перемычек прорывоопасных озёр Прогресс и Дискашн (оазис Холмы Ларсеманн, Восточная Антарктида), выполненные методом георадиолокации. Дополнительно проведены бескерновое механическое бурение и аэрофотосъёмка с использованием беспилотного летательного аппарата. На примере изученных водоёмов установлены основные геолого-гляциологические тенденции формирования прорывных паводков ледниковых озёр
Летняя кромка льдов и осенние сроки устойчивого ледообразования в морях Лаптевых, Восточно-Сибирском и Чукотском в 1981–2018 гг.
Get PDFThe spatial and temporal variability of ice edge position at the end of the summer period, the dates of the beginning of stable ice formation in early autumn in the Russia’s Eastern Arctic seas (Laptev, East-Siberian, and Chukchi) during 1981–2018 together with climate changes in the 21st century are analyzed. The analysis of summer and autumn ice characteristics shows certain common features occurring for many years: since the beginning of the 21st century, ice conditions have significantly improved, which is due to the more Northern position of the ice border in August–September and later dates for the beginning of stable ice formation in September–October. On average for the period 2002–2018, the ice edge at the end of the period of clearance from ice shifted (as compared to 1981–2001) in a northerly direction by about 400–500 km. Observations did show that in 2003–2018, the beginning of stable ice formation in the autumn season (as compared to 1981–2002) occurred later by about three weeks. The maximum northward shift of the ice edge was first observed (since 2002) on the aquatory to the East of the New Siberian Islands, and then (since 2011) – to the West of them. The greatest anomalies of late dates (onset) of ice formation were first observed (since 2003) in the Chukchi Sea, then (since 2008) – in the Laptev Sea, and later (since 2014) – again in the Chukchi Sea. Long-term changes in the ice conditions occur according to the similar scenario: first, an anomaly of the latitudinal position of the edge or the date of the ice formation beginning was formed in the Eastern part of the studied aquatory, and then this anomaly shifted from East to West. At the same time, the anomaly diminishes in the East that makes it possible to interpret the observed natural changes as fluctuations of the «ice wave» type. Taking into account the wave features of changes in summer and autumn ice indicators, we can assume that in the 2020s we should expect a similar continuation of natural fluctuations in changes in ice conditions, which will be accompanied by a spatial shift of the ice edge in the South direction and relatively earlier dates for the beginning of ice formation.По сравнению с 1980–90‑ми годами с начала 2000‑х годов в восточных арктических морях России происходят кардинальные изменения, связанные с более северным положением кромки льдов и более поздними сроками начала ледообразования. Многолетние изменения летних и осенних ледовых условий в ХХI в. происходят по типу волновых колебаний, при которых область наибольших ледовых аномалий постепенно смещается из Чукотского моря в море Лаптевых. Предполагается, что в 2020‑х годах (по сравнению с 2000–20‑ми годами) следует ожидать более южного пространственного положения кромки льдов и более ранних дат начала ледообразования
Реконструкция баланса массы ледника Сары-Тор по метеорологическим данным
Get PDFMass balance bn is the most important indicator of a glacier evolution. However, after the decay of the USSR direct measurements of bn performed in 1985–1989 in the Inner Tien Shan, including the Sary-Tor Glacier in Ak-Shiyrak Massif, had been desisted. As a result the available series of the data were limited 1989. Measurements in this area were renewed only in 2015. This paper is devoted to restoring the continuity of the mass-balance series over the period of the gap in measurements and extending this series down to 1929, i.e. to the beginning of regular meteorological observations on the reference HMS Tien Shan (3660 m a.m.s.l.). Accumulation was reconstructed using a linear relationship of bn with the air temperature and precipitation sum. Reconstruction of ablation was based on its cubic relationship with the temperature (modified Krenke– Khodakov formula) or on two-parameter linear approximation using the air temperature and wind velocity. Thereby, the decade of direct instrumental measurements (1984/85–1988/89 and 2014/15–2018/19) resulted in deriving and analyzing continuous 90-year-long series of annual values of bn and its constituents, analytical type of referent glacio-meteorological equations being assumed unchanged in time. Reconstruction for the Sary-Tor Glacier reveals a dominant trend towards the mass loss with rare and short-time episodes of retarding the negative tendencies. The comparison made with the long series of mass balance of other glaciers in Asia indicates a certain degree of synchronicity, which is slightly disturbed in recent years: the degradation of Sary Tor Glacier tends to progress more intensively. Conclusions about its evolution are particularly relevant in connection with the assumption about the impact of the Kyrgyz-Canadian gold mining company «Kumtor Gold Company» on local ecosystems against the background of its interest in expanding the mining zone to the bowels of the Earth under the tongue of this glaciological object.По длинным рядам метеоданных ГМС Тянь-Шань восстановлены годовые значения аккумуляции, абляции и баланса массы долинного ледника Сары-Тор в массиве Ак-Шийрак. В основе поиска зависимостей – прямые гляциологические измерения в 1980-е и 2010-е годы. Реконструкция позволила заполнить пробел между этими периодами и продлить ряд до 1930 г. Результаты сравниваются с более ранними реконструкциями, а также с длинными балансовыми рядами опорных ледников Азии
Азотсодержащие вещества в снеге районов падения ступеней ракеты-носителя «Протон» в 2009–2019 гг.
Get PDFThe article presents analysis of the snow pollution caused by flights of the Proton launch vehicles launched from the Baikonur cosmodrome in 2009–2019. Data on 1477 snow samples collected in areas in Central Kazakhstan, southeast of Western Siberia, and northeast of the Altai are summarized to assess the pollution. In the uninhabited areas in Central Kazakhstan, where rocket fuel is spilled, pollution of snow was detected at 18 fall sites at a distance of up to 10 m from the fragments of the stages. The background value of pH is estimated as 6.6±0.9. The following nitrogen-containing compounds (mg/l) were found in snow taken in the unpolluted territories of Central Kazakhstan: NO3 (2.3±3.4), NH4+ (0.75±0.98) and to a lesser extent NO2– (0.015±0.019); asymmetric dimethylhydrazine and nitrosodimethylamine were not detected. The chemical composition of snow in the fall areas of the second stage of the Proton launch vehicle is in a good agreement with the background level of nitrogen-containing substances of natural origin. There were no traces of the rocket fuel. Thus, in the snow on the KetskoTym plain (southeast of Western Siberia) and northeast of Altai, the background content of nitrogen-containing substances is equal, respectively (mg/l): NO3– (0.36±0.28 and 0.47±0.59); NH4+ (< 0.05 and 0.20±0.27); NO2– (0.048±0.016 and 0.027±0.073), which is determined by regional features and distance from sources of nitrogen-containing substances. The data obtained allow us to conclude that the areas of the rocket falls on the above territories are not an environmental hazard to the environment by the concentration of nitrogen-containing substances in the snow.Обобщены данные по 1477 пробам снега из районов падения ступеней ракеты-носителя «Протон» в Центральном Казахстане, на юго-востоке Западной Сибири и северо-востоке Алтая. В безлюдных территориях Центрального Казахстана, куда попадает ракетное топливо, достоверное загрязнение снега установлено на расстоянии не более 10 м от фрагментов падения первой ступени. Химический состав снега районов падения второй ступени (юго-восток Западной Сибири и северо-восток Алтая) отражает фоновые уровни азотсодержащих соединений природного происхождения и показывает отсутствие компонентов ракетного топлива. Очевидно, что районы падения и первой, и второй ступеней ракет-носителей «Протон», запускаемых с космодрома Байконур, не представляют собой зоны экологического бедствия
Позднеплейстоценовое оледенение и отступание ледникового покрова на шельфе Южно-Оркнейского плато, Западная Антарктика
Get PDFThe research aims to provide insight into reconstruction of the Late Pleistocene glaciations and ice retreat that followed the Last Glacial Maximum. The study is based on multi-channel seismic profiling and multibeam survey conducted on the shelf during the 63-rd Russian Antarctic Expedition (2018) on RV «Akademik Alexander Karpinsky». The 560-channel, 7000-m-long streamer and the Atlas Hydrosweep MD-3/30 multibeam echo-sounder were used for seismic and multibeam survey, respectively. In addition, previously collected seismic data available from the Antarctic Seismic Data Library System and bathymetry data from the «International Bathymetry Chart of the Southern Ocean» (IBCSO) Project were involved for interpretation. The multibeam survey was carried out within the Signy Trough and its flanks with depths ranging from 180 to 400 m, and covered the area of about 1500 km2. The data were collected along 43 profiles spaced at 750 m to ensure enough overlap between swaths. Variety of submarine glacial landforms formed by grounded ice was identified on shelf of the South Orkney Plateau with use of seismic and multibeam data. The most prominent of these features is the large terminal moraine at the middle shelf (previously described as the mid-shelf break) marking the greatest ice extent at the LGM. Oceanward of the large terminal moraine, the plateau-like feature (delineated by 350 and 425 m isobaths) with relatively steep outer slope is recognized from seismic data and interpreted as the distal terminal moraine formed during the pre-LGM Pleistocene glaciation. Within the Signy Trough, submarine glacial landforms mapped by multibeam survey, reflect ice retreat after the LGM; these landforms include: subglacial lineation at the western flank of the northern Signy Trough indicating fast flowing grounded ice, transverse recessional moraine ridges, lateral shear moraine on the western flank and lateral marginal moraine on the eastern flank of the Trough, two grounding zone wedges, streamlined features (drumlins) and an ice-proximal fan (presumably). The end moraine was also identified in the eastern flank of Signy Trough. It is thought to be formed due to ice (outlet glacier) re-advance during the Antarctic Cold Reversal. Numerous iceberg plough-marks were observed at least down to 370 m water depths.По данным сейсмического профилирования и детальной съёмки с помощью многолучевого эхолота на шельфе Южно-Оркнейского плато идентифицированы подводные ледниковые формы рельефа, которые маркируют распространение ледникового покрова в периоды четвертичных оледенений и этапы его отступания в позднем плейстоцене. Предполагается, что максимальное распространение ледника с его налеганием на дно произошло в один из периодов похолодания плейстоцена. Во время последнего ледникового максимума ледник достигал среднего шельфа и сформировал крупную конечную морену. После этого началось его отступание, которое происходило неравномерно. В период Антарктического холодного реверса в районе долины Сигню установлено повторное наступание ледника
Сокращение ледников Восточного Алтая (Шапшальский центр) после максимума малого ледникового периода
Get PDFBased on the analysis of remote data and field observations, we reconstructed the glaciation of the Shapshal Center (Eastern Altai) for the maximum of the Little Ice Age (LIA) and by the state of the glaciers as of 2001. At the maximum of the LIA, glaciation was represented by 358 glaciers with a total area of 84.43 km2. It was found 87% reduction of the total area of glaciers in the interval from the LIA maximum to 2015. During the reduction, valley glaciers disintegrated and glaciers in the Kargy River basin disappeared. The moraines of the LIA have low lake coverage (0.17% of area), therefore a probability of their breakthrough is low. We obtained data on the retreat of the Mushtuk Glacier (№ 78), the largest one of the Shapshal center, in five time slices from the LIA maximum. The highest retreat rates were reconstructed in the interval 1989–2001, but in the interval 2010–2016 the average rates decreased to 5 m/year. Changes in the mass balance index of the Mushtuk Glacier between from 1961 to 2018 were calculated. A sharp decrease in the mass balance in the 1990s and stabilization of values at a low level after 2001 were found. According to the calculations, the response time of the Mushtuk Glacier was about 9 years. If the current climatic conditions persist, there is reason to assume stabilization of glaciers in the coming years.Реконструированы ледники малоисследованного Шапшальского центра оледенения на Восточном Алтае в максимум малого ледникового периода, проанализирован характер их последующего сокращения. Детально рассмотрено сокращение крупнейшего ледника Шапшальского хребта по пяти временным срезам c 1955 по 2019 г. Проведены расчёты индекса баланса массы ледника и времени его климатического отклика
Глобальные гляциологические модели: новый этап в развитии методов прогнозирования эволюции ледников. Часть 1. Общий подход и архитектура моделей
Get PDFFor several decades, mathematical models of mountain glaciers and ice sheets have been used to study the dynamics of the cryosphere. In recent years, a new step in glaciological modeling has made possible to recon- struct processes in mountain-glacial systems both regionally and globally. The proposed review analyses rea- sons to use this possibility for global glaciological models, key assumptions and methods, general approaches and differences between individual models. Global glacier modeling is a rapidly developing field. This became possible only after the data on all glaciers of the world appeared in the Randolph Glacier Inventory in 2012. The ice thickness inversion procedures discussed in this review made it possible to calculate the initial volume and geometry of glaciers. Methods of varying complexity were used to regionalize global climate data and cal- culate glacier mass balance. Modeling the dynamics of glaciers required the adaptation of simplified schemes to represent the fluidity of ice (or the flow of ice). To date, only two global glacier models contain ice dynamics calculations based on Glenn's law and the diffusion equation: OGGM and GloGEMflow. Simulation results are subject to uncertainties due to input errors, climate predictions, model approximations, and calibration proce- dures. A new stage in the development of methods opens up opportunities to use a number of new directions in the study of the mechanisms that control the evolution of glaciation, depending on the implementation of a particular climatic scenario. Global glacier models make possible to build glaciological projections, calculate potential changes in the regime of glacial runoff, as well as assess risks and predict the occurrence of dangerous processes caused by changes in glaciation parameters, such as mudflows, landslides, and glacial lake outbursts.В обзоре рассмотрены предпосылки возникновения глобальных гляциологических моделей, ключевые допущения и методы, общие подходы и различия между отдельными моделями. Глобальные модели ледников позволяют строить гляциологические проекции, рассчитывать потенциальные изменения в режиме ледникового стока, а также оценивать риски и прогнозировать возникновение опасных процессов (сели, оползни, прорывы ледниковых озер), обусловленных изменениями параметров оледенения