Гидрологическая характеристика озёр восточной части полуострова Брокнес, холмы Ларсеманн, Восточная Антарктида

Broknes 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

Advanced Mapping of Optically-Blind and Optically-Active Nitrogen Chemical Impurities in Natural Diamonds

Natural diamonds with a rich variety of optically blind and optically active nitrogen impurity centers were explored at a nano/microscale on the surface and in bulk by a number of advanced chemical and structural analytical tools in order to achieve a comprehensive characterization by establishing enlightening links between their analysis results. First, novel compositional relationships were established between high-energy X-ray photoelectron spectroscopy (XPS) and low-energy Fourier-transform infrared vibrational spectroscopy (FT-IR) signals of nitrogen impurity defects acquired in the microscopy mode at the same positions of the diamond surface, indicating the verification XPS modality for qualitative and quantitative FT-IR analysis of high concentrations of nitrogen and other chemical impurity defects in diamond. Second, depth-dependent spatial distributions of diverse photoluminescence (PL)-active nitrogen defects were acquired in the confocal scanning mode in an octahedral diamond and then for the first time corrected to the related Raman signals of the carbon lattice to rule out artefacts of the confocal parameter and to reveal different micron-scale ontogenetic layers in the impurity distributions on its surface. Third, intriguing connections between local structural micro-scale defects (dislocation slip bands of plastic deformation zones) visualized by optical microscopy and Raman microspectroscopy, and related distributions of stress-sensitive PL-active nitrogen impurity defects in the proximity of these planes inside bulk diamonds were revealed. These findings demonstrate the broad instrumental opportunities for comprehensive in situ studies of the chemical, structural, and mechanical micro-features in diamonds, from the surface into bulk. © 2022 by the authors.Ministry of Education and Science of the Russian Federation, Minobrnauka: 075-15-2021-677; Ministry of Science and Higher Education of the Russian FederationThis research was funded by the Ministry of Science and Higher Education of the Russian Federation (Project # 075-15-2021-677, Ural Federal University Program of Development within the Priority-2030 Program).The equipment of the Ural Center for Shared Use “Modern nanotechnology” of Ural Federal University (Reg.# 2968), which is supported by the Ministry of Science and Higher Education RF. The samples were provided by Geological Faculty of Moscow State University (G.K.)

Local polarization reserval in waveguides created in lithium niobate single crystals by high energy ion irradiation

The equipment of the Ural Center for Shared Use “Modern Nanotechnology” Ural Federal University has been used

AZINE-GRAPHENE-DYAD: SYNTHESIS AND PROPERTIES

This work was supported by the Russian Science Foundation, project № 22-13-00298

Особенности уровенного режима приледниковых моренно-подпрудных озёр в стадии роста (на примере озёр горного массива Таван-Богдо-Ола, Юго-Восточный Алтай)

Assessment of the dynamics of high-altitude glacial lakes is becoming increasingly important in the context of modern climate instability. The formation of new periglacial lakes and the growth of existing lakes as a result of the reduction of glaciers are recorded almost all over the world, including Russia. A rapid increase of a periglacial lake size may lead to the formation of an outburst flood. In this context, in order to prevent outburst floods, it is necessary to investigate outburst hazard lakes at all stages of their development. The periglacial lakes of the Altai mountains have been little-studied in comparison with other mountainous areas. At the same time, they are also characterized by the formation of new lakes during the period of climate nonstationarity. It was confirmed by the identified statistically significant trends in average monthly air temperatures during the ablation period. Based on the analysis of multi-temporal satellite images, it was found that the number of new periglacial lakes in the high-altitude territories of the Altai Republic (Katunsky ridge, North-Chuya ridge, South-Chuya ridge and the Tavan-Bogdo-Ola mountain massif) is increasing exponentially. For a more detailed survey and field hydrological studies, the authors chose the recently formed periglacial Lake Barsovo and periglacial Lake Gachi-Kol. Both lakes located within the northen slope of the Tavan-Bogdo-Ola mountain massif. Field observations, which were carried out in July-August 2021, have shown that both lakes are currently at the transgressive stage of development (growth stage). The transgressive phase of the lakes development is characterized by a rapid increase in size by the end of the warm period and a complex level regime on both diurnal and annual scales, due to the fact that both lakes are adjacent to the glacier.На основе анализа изменчивости гидролого-морфометрических характеристик озёр с применением спутниковых изображений и данных полевых гидрологических наблюдений, выполненных авторами в июле – августе 2021 г., описаны особенности гидрологического режима двух приледниковых озёр с трансгрессивной фазой развития, расположенных на территории горного массива Таван-Богдо-Ола (Республика Алтай)

Обширная депрессия в леднике Долк, Восточная Антарктида

In the afternoon of January 30, 2017, the wide depression in the western part of the Dålk Glacier, East Antarctica, was formed. By coincidence, aerial surveying was carried out in this area, so it is possible to assess the extent of this catastrophic phenomenon. Aerial photos were taken on January 20 and February 9, 2017, respectively. Based on the photographic data, the size of the depression were 183 × 220 m, and its area reached 40.260 m2. The depth of the depression in the early days was 20–30 meters; the maximum measured depth was 43 m. An approximate volume of the cavern was about 884,013 m3. On preliminary conclusions, this event should be the similar jökulhlaups, when the water of Boulder Lake broke the icy border and rushed downstream under Dålk Glacier to Prudz Bay.30 января 2017 г. на участке дороги, соединяющей российскую станцию Прогресс и китайскую станцию Зонгшан с аэродромом и трассой следования санно-гусеничных походов на внутриконтинентальные станции Восток и Кунлун, в западной части ледника Долк (Dålk Glacier), в районе российской полевой базы Прогресс-1 образовался провал. Дана характеристика этого провала

Прорыв озера Прогресс (Восточная Антарктида): подходы к оценке характеристик прорывного паводка

On January 14, 2019, a breakthrough of water masses occurred on the Lake Progress (the oasis of the Larsemann hills, East Antarctica) with the formation of a flash flood. During the summer field seasons of the 63rd and 64th Russian Antarctic Expeditions (2017–2019), comprehensive hydrological, GPR and geodetic surveys were conducted in this area to ensure the safety of transport operations. The results of field measurements and calculations based on mathematical modeling of the breakthrough flood from the Lake are presented. The purpose of this study was to compare field observations and model calculations of the breakthrough flood and then to verify the existing model of Yu.B. Vinogradov on real data, since detailed observations of breakthrough floods of lakes of the Antarctic oases have not been previously carried out. The results of complex hydrological and geophysical investigations of LH73–Progress–Sibtorp lake system focused on areas where lake outburst are possible (snow-ice dams) made possible to formulate phenomenological model of the outburst process. It was emphasized that the lake water was discharged through a tunnel developed in the snow–ice dam, which subsequently evolved into a real riverbed. The maximum water discharge was formed approximately in 7.5 h after the start of the outflow, and it was estimated 5.4 m3s-1 according to the in-situ measurements, and 4.94 m3s-1 – by the model. The calculated volume of the flood is 76 320 m3. The differences between the model and in-situ measurements are about 9% that can be explained by the fact that the time of water retention by the snow-ice dam is not considered in the model.При исследованиях в 2018/19 г. в районе станции Прогресс (Восточная Антарктида) авторы наблюдали прорыв системы озёр Прогресс–Сибторп. Приводятся феноменологическое описание этого процесса, а также результаты наблюдений и математического моделирования

Vast ice depression in Dålk Glacier, East Antarctica

In the afternoon of January 30, 2017, the wide depression in the western part of the Dålk Glacier, East Antarctica, was formed. By coincidence, aerial surveying was carried out in this area, so it is possible to assess the extent of this catastrophic phenomenon. Aerial photos were taken on January 20 and February 9, 2017, respectively. Based on the photographic data, the size of the depression were 183 × 220 m, and its area reached 40.260 m2. The depth of the depression in the early days was 20–30 meters; the maximum measured depth was 43 m. An approximate volume of the cavern was about 884,013 m3. On preliminary conclusions, this event should be the similar jökulhlaups, when the water of Boulder Lake broke the icy border and rushed downstream under Dålk Glacier to Prudz Bay

Breakthrough of Lake Progress (East Antarctica): a phenomenological model and approaches to assessing the characteristics of a flash flood

On January 14, 2019, a breakthrough of water masses occurred on the Lake Progress (the oasis of the Larsemann hills, East Antarctica) with the formation of a flash flood. During the summer field seasons of the 63rd and 64th Russian Antarctic Expeditions (2017–2019), comprehensive hydrological, GPR and geodetic surveys were conducted in this area to ensure the safety of transport operations. The results of field measurements and calculations based on mathematical modeling of the breakthrough flood from the Lake are presented. The purpose of this study was to compare field observations and model calculations of the breakthrough flood and then to verify the existing model of Yu.B. Vinogradov on real data, since detailed observations of breakthrough floods of lakes of the Antarctic oases have not been previously carried out. The results of complex hydrological and geophysical investigations of LH73–Progress–Sibtorp lake system focused on areas where lake outburst are possible (snow-ice dams) made possible to formulate phenomenological model of the outburst process. It was emphasized that the lake water was discharged through a tunnel developed in the snow–ice dam, which subsequently evolved into a real riverbed. The maximum water discharge was formed approximately in 7.5 h after the start of the outflow, and it was estimated 5.4 m3s-1 according to the in-situ measurements, and 4.94 m3s-1 – by the model. The calculated volume of the flood is 76 320 m3. The differences between the model and in-situ measurements are about 9% that can be explained by the fact that the time of water retention by the snow-ice dam is not considered in the model