Ice and Snow (E-Journal) / Лёд и Снег
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Волновые структуры в ледяном поле и их влияние на прочность солёного льда
Get PDFThe heterogeneity of the strength of the ice field of the dynamic type of formation with an area of 800 m2 was investigated in time and space. It is shown that stationary periodic wave structures are formed in a closed volume of an ice field lying on the surface of a liquid in a rectangular basin. In a case of absence of any external influences, the dominant source of elastic waves in the ice is the coherent radiation of them on freezing of water, i.e. the ice field itself. Another wave structures, i.e. standing waves, form secondary ice textures in the ice field with diminished strength. Local hardness of ice was chosen as the criterion of strength. The recurrence of local hardness values as a function of coordinates of the measurement points in the longitudinal and transverse profiles of the ice field was determined. The hardness values vary from 40 to 60% with an axial force measurement error of 5%. The experimental relations are approximated by periodic curves, in which the maxima and minima of local hardness correlate with the nodes and antinodes of standing waves, respectively. The decrease in local ice hardness in the secondary textures is explained by high-frequency dynamic metamorphism. The wavelengths corresponding to bending-gravitational and longitudinal waves are identified, with the interference of which stationary periodic wave structures are formed. A similar regularity of changes in local hardness was revealed also in a river ice. The results obtained allow us to consider nonlinear wave phenomena as one of the factors controlling the spatial-temporal variability of the ice strength characteristics.Установлено, что в ледяном поле динамического типа формирования под действием стоячих волн образуются стационарные периодические волновые структуры. Определены масштабы таких структур. Изменение локальной твёрдости объясняется высокочастотным динамическим метаморфизмом льда в зонах пучностей стоячих волн. Показано, что источником упругих колебаний может быть когерентное излучение упругих волн при замораживании воды. Формирование аналогичных волновых структур в природном льде подтверждено полевыми измерениями твёрдости в речном ледяном покрове. Нелинейные волновые явления рассматриваются как один из факторов пространственно-временнóй изменчивости прочностных характеристик льда
Учёт внутренней структуры киля тороса при термодинамических расчётах эволюции консолидированного слоя
Get PDFMaterials from long-term field observations of the internal structure of ice hummocks in the Arctic seas were analyzed. Empirical expressions describing the porosity distribution of the underwater part of a newly-formed hummock depending on the depth and width of the keel had been derived. A two-dimensional thermodynamic ice hummock model taking into account these expressions has been developed. The influence of porosity distribution on the results of thermodynamic calculations of ice hummock evolution is considered. It is shown that the porosity distribution in the ice hummock keel defines the growth of the consolidated layer to a large extent. The screening effect of the ice hummock sail on the evolution of the consolidated layer is less important. As a result, during the life-time of the ice hummock, the thickness of the consolidated layer in its central part becomes greater than at its edges. The smaller the size of the ice hummock, the faster this effect appears.На основании обработки данных многолетних наблюдений рассматриваются пространственная неоднородность заполнения подводной части тороса и её влияние на скорость промерзания киля тороса при термодинамическом моделировании. Учёт пространственной неоднородности запол- нения киля способствует решению вопроса о распределении толщин консолидированного слоя в поперечном сечении тороса для разных этапов эволюции торосистого образования на протяжении зимнего сезона
Геохимия снежного покрова в зоне влияния запуска ракеты-носителя (Якутия)
Get PDFResults of ecological and geochemical study of snow cover on the areas of the fall of the separating parts of the launch vehicles Soyuz-2 are discussed. The territories are the Aldan and Vilyuysky districts of Yakutia. The state of the environment was investigated at the sites in both situations, i.e. before the launch and after the fall of the separating parts of the rocket carriers. The background chemical composition of the snow cover in these regions is hydrocarbonate and ultra-fresh with low concentrations of trace elements. After the launch and fall of the rocket stages, the total chemical composition of snow remained bicarbonate, but the content of the elements P, Fe, Sr, Pb and phenols increased on the territory of the Aldan district, while in the Vilyuysky districts increasing elements were Fe, Sr, Pb, Li, Al, Mn and phenols. Pollution of the snow cover with metals and organic compounds was revealed directly under the fragments of the rocket stages, however occurrence of this contamination was limited to the radius of influence no longer 100 m. The larger low-contrast technogenic anomalies were related to Pb and phenols. The qualitative and quantitative characteristics of technogenic anomalies did rapidly reduce with distance from fragments of the rocket carriers. When snow melts, the main part of the pollutants flows down over the frozen ground to the water streams and bodies, and that is why no contrasting technogenic lithochemical anomalies were found in the soils under the fragments. Thus, our results demonstrate that the negative environmental impact on the environment in the areas of falling fragments of the Soyuz-2 carrier is limited to boundaries of the local territory and does not present any significant hazard to the environment and the health of population.В районах падения отделяющихся частей ракеты‐носителя «Союз‐2» на территории Якутии иcследован снежный покров на мониторинговых площадках до запуска и после падения отделяющихся частей ракеты‐носителя, когда в снежном покрове формируются аномалии металлов и органических соединений. Негативное экологическое воздействие на природную среду в районах падения остатков ракеты ограничено локальными территориями
Аннотированная библиография русскоязычной литературы по гляциологии за 2018 год
Get PDFThe proposed annual bibliography continues annotated lists of the Russian-language literature on glaciology that were regularly published in the past. It includes 297 references grouped into the following ten sections: 1) general issues of glaciology; 2) physics and chemistry of ice; 3) atmospheric ice; 4) snow cover; 5) avalanches and glacial mudflows; 6) sea ice; 7) river and lake ice; 8) icings and ground ice; 9) the glaciers and ice caps; 10) palaeoglaciology. In addition to the works of the current year, some works of earlier years are added, that, for various reasons, were not included in previous bibliographies.Предлагаемая библиография продолжает ежегодные аннотированные списки русскоязычной литературы по гляциологии, которые регулярно публиковались в прошлом. Помимо работ текущего года в списке встречаются работы более ранних лет, по тем или иным причинам не вошедшие в предыдущие библиографические списки
Чувствительность результатов моделирования сезонного промерзания к выбору параметризации теплопроводности снежного покрова
Get PDFThe relationship between the results of calculations of the dynamics of the temperature regime of the in freezing and thawing soil profile with the heating effect of the snow cover is considered. To analyze this connection, two coupled models are used: the model of formation and degradation of snow cover in winter and the model of heat transfer and soil moisture transport in underlying vadoze zone profile. Parametrization of the influence of the snow cover, which at each calculated moment of time has the current average density and depth, on the dynamics of the temperatures of the soil profile is due to the use of its specific thermal resistance, which depends on its current depth and the thermal conductivity coefficient. The coefficient of thermal conductivity of the snow cover is related with its density using six different published empirical relationships. Modeling of heat transfer in freezing and thawing soil is carried out on the example of the field site for monitoring the thermal regime located on the territory of the Zvenigorod Biological Station of Moscow State University. It is shown that the well-known relationships give similar curves for the dynamics of the depth of seasonal freezing, including the degradation of the seasonal freezing layer in the spring period, with the same dynamics of the snow cover. However, the maximum penetration depth of the zero isotherm differs significantly for different snow conductivity-snow density relationships. The tested six relationships were divided into three groups. Minimal freezing is provided by the Sturm model and the effective medium model. The average and rather poorly differentiating freezing from each other is given by the Pavlov, Osokin et al. and Jordan relationships. The greatest value of the freezing depth is obtained with using Pavlov’s relationship with a temperature correction. Рассматривается связь результатов расчёта динамики температурного режима пород зоны аэрации с отепляющим влиянием снежного покрова. Шесть протестированных моделей разделены на три группы. Минимальное промерзание при одинаковых условиях накопления снега дают модели М. Стурма и эффективной среды. Среднее промерзание показывают модели А.В. Павлова, Н.И. Осокина с соавторами и Р. Джордана. Наибольшее значение глубины промерзания даёт модель А.В. Павлова с температурной поправкой
Методика учёта лавинной опасности при территориальном планировании в России
Get PDFThe legislation of the Russian Federation establishes the need to take into account hazardous natural processes and their parameters in territorial planning, as well as presentation of them in the relevant documentation in the form of maps. In a number of countries, there is a long-standing practice of mapping the avalanche zones basing on the definition of different levels of danger, which are used to limit or ban the construction in avalanche zones, as well as to project the anti-avalanche activities. Russia has experience in assessing risk and mapping the avalanche danger, but the practice of making such plans in our country is still not developed. The purpose of this work is to determine and plot on map avalanche zones on the example of one of the actively developed mountain regions of Russia. The all-season mountain resort «Gorky Gorod», located on Krasnaya Polyana in the Krasnodar region, was chosen as the object of study. Two approaches to the accounting and mapping of avalanche hazard in territorial planning were tested. In the first case, occurrence and pressure of avalanches were the determining factors. In the second case, critical avalanche pressure values were used to determine their destructive impact effect. To determine indexes (indicators) of the avalanche hazard, the simulation of snow avalanches in the RAMMS program was performed. According to the results of modeling for area of the «Gorky Gorod» resort schemes of the avalanche zones were constructed on the basis of two different approaches, having no account for the anti-avalanche measures used there. A more detailed plan based on a combination of these two approaches had also been drawn up and analyzed. The required criteria for determining the boundaries of zones with different levels of the danger are the subject for discussion. However, the proposed division of avalanchedangerous territory into zones with different levels of the hazard at the stage of territorial planning meets the requirements of the legislation and contributes to improving human security, reducing the avalanche risk, and mitigating the consequences of emergencies caused by avalanches.Исследование, направленное на совершенствование учёта лавинной опасности при территориальном планировании, выполнено для горного курорта «Горки Город» на Красной Поляне в Краснодарском крае. Апробированы два подхода к учёту лавинной опасности и их комбинации. Значения показателей лавинной опасности определены путём моделирования лавин в программе RAMMS. По результатам моделирования для территории курорта «Горки Город» составлены планы лавиноопасных зон.
Гидрологическая характеристика озёр восточной части полуострова Брокнес, холмы Ларсеманн, Восточная Антарктида
Get PDFBroknes Peninsula (the area of the Progress station, Larsemann Hills, Princess Elisabeth Land, East Antarctica) is characterized by the presence of well developed hydrographic network consisting of reservoirs located not only in the bedrock, but also inside the glacier thickness and on its surface. As a rule, most of them are dammed by natural snowice weirs, which are often destroyed during the Antarctic summer. As a result of this process, glacial water outburst may occur. In the course of the summer season of the 63‑th Russian Antarctic Expedition (RAE) intensive hydrological field observations were carried out for identification and comprehensive investigation of potentially outburstprone reservoirs located in close proximity to Russian and foreign stations and field bases (area of the Progress station and the field base Law-Racovita). The works included: the organization of temporary pile and depth-stick water gauge stations, mapping positions of the shoreline of lakes (reservoirs), bathymetric surveys of them, as well as field hydro-chemical express analyses. Based on the results of the level measurement, it was found that most of the lakes of the oasis are characterized by a sharp drop in the height of the water surface level associated with the breakthroughs. In particular, the authors witnessed the breakthrough of the Discussion Lake, which occurred on January 22, 2018. This resulted in decrease of the water level by 0.95 m. Based on the data of the bathymetric surveys, the morphometric (hydrometric) characteristics of the lakes were calculated and detailed grids (regular net of rectangular matrices, in the nodes of which some effective values of the mapped values are located) were formed for the following numerical modeling of hypothetical and real breakthroughs of water bodies and construction of estimated hydrographs.Приведены результаты гидрологических исследований прорывоопасных озёр, расположенных недалеко от отечественных и зарубежных станций и полевых баз. Установлены основные прорывоопасные водоёмы и сформированы подробные гриды (регулярная сеть прямоугольных матриц, в узлах которых располагаются значения картируемых величин) исследуемых водных объектов для проведения математического моделирования
Исследования Верхнеангарской группы ледников
Get PDFGlaciers of the Verkhneangarsky mountain range are discovered in 2017-2018 and require detailed investigation and cataloging. This group of glaciers includes glaciers of the corrie and morphological types, and, according to the sizes, they should be qualified as small forms of glaciation. Four glacial formations were found during field studies of 2017-2018 together with several snow patches and stone glaciers; these four glaciers were measured and described. The temperature of ice in the glaciers of this region was measured during the investigations. Data on the ice temperature close to the temperature of the surface permafrost layer explain one of the conditions for existence of glaciers in the temperate zone at altitudes of 1800-2000 m. The dynamics of some glacial formations is analyzed in comparison with their present-day sizes, obtained as a result of interpretation of images from Bing maps and Sentinel-2 services, as well as with images of the CORONA mission (1967). The relative stability of the local glacial formations under climate change is related to the underlying permafrost as well as to the forms of occurrence in the relief, and a degree of closure by the stone cover.В результате полевых исследованиях в Верхнеангарском хребте обнаружены новые ледники, дано их описание, приведены результаты измерений, обсуждаются причины существования ледников в этом районе. По снимкам миссии CORONA определены размеры некоторых ледниковых образований на 1967 г
Нерастворимые фракции аэрозолей и тяжёлых металлов в свежевыпавшем снеге на северо-западе Кольского полуострова в 2018 г.
Get PDFAs a result of studies of newly fallen snow in the North of the Kola Peninsula, it was found that from January to May 2018 its density amounted, on the average, to 0.160±0.006 g/cm3 (n = 82), and pH of melted snow water - 6.87±0.14 (n = 47). Neutral and slightly alkaline reaction of snow water impedes the mobility of heavy metals in the insoluble fraction of aerosols. In loose fresh snow (density less than 0.2 g/cm3) the content of solid aerosols increases as the snow density grows. The average concentration of solid aerosol particles in freshly fallen snow is 4.04±0.24 mg/l (n = 47). Over the winter period of 2018 (120 days), about 1.85-2.37 thousand tons of aerosol substance precipitated on the underlying surface of the area under investigation. The daily deposition of aerosols averaged 1.03-1.33 mg m-2, and together with solid precipitation, mg m-2 day-1: Zn - 12.5-14.2, Cu - 2.2-2.5, Pb - 0.58-0.66, Cd - 0.31-0.42. According to the results of our researches, two impact areas were previously identified, both allocated to large regional centers. The Murmansk coast is divided into three background areas, each of which corresponds to its natural landscape complex.С января по май 2018 г. на северо-западе Кольского полуострова проведено исследование концентраций твёрдых нерастворимых частиц в свежевыпавшем снеге, а также потока твёрдых аэрозолей на поверхность земли в зимний период. Средняя концентрация твёрдых нерастворимых частиц в свежевыпавшем снеге составляет 4,04±0,24 мг/л (п = 47), что выше фоновых значений для западной Арктики. Поток твёрдых аэрозольных частиц в среднем равен 2,10±0,09 мг м2 за один снегопад