Glacier Water Research Articles

Assessment of metals and other trace elements in the drinking water along River Indus, Allai and Nagar

Trace element contamination in water is a global issue due to its widespread occurrence and health effects. Regular intake of elevated metal levels in drinking water can unequivocally cause several types of cancers. This study was primarily focused to assess the quality of drinking water in Allai, Nagar and along River Indus. So for this study a total of 64 spring, 14 waterfall and 7 glacier water samples were collected. Additionally, 13 sediment samples were also collected from Allai and Nagar which were located in the vicinity of mountainous River Indus, Pakistan. The samples were tested for arsenic, calcium, chromium, copper, iron, lead, magnesium, potassium, sodium and zinc using inductively coupled plasma optical emission spectroscopy so as to get the elemental concentrations in parts per billion. The range of metals and other trace elements were compared with the guidelines of World Health Organization (WHO) and the standards laid down by Environmental Protection Agency of Pakistan. The results revealed the (minimum-maximum) concentrations (µg/L) of drinking water quality parameters as follows: arsenic 0-0.06, calcium 1.74-176.87, chromium 0-0, copper 0-0, iron 0-0.25, sodium 1.27-292, potassium 0-24.01, magnesium 0.05-120.22, lead 0-0 and zinc 0-0. Moreover, the (minimum-maximum) concentrations (µg/L) of sediment samples were recorded as arsenic 0-0. 88, calcium 42.98-2068, chromium 0.16-0.65, copper 0.12-1.76, iron 166-544, sodium 8.99-15.36, potassium 35.57-247, magnesium 47.14-453, lead 0-0.23 and zinc 0.67-1.66. The study concluded that all the samples collected from the vicinity of River Indus had elemental concentrations within the recommended guidelines set by the National Drinking Water Quality Standards of Pakistan and WHO. Furthermore, a detailed study encompassing samples from the springs, glaciers, waterfalls and lakes is recommended to evaluate the possible trace element contamination either due to deposition or mixing of metal bearing rocks with water both in the low lying and highland areas of Upper Indus Basin. The outcomes of this research can be useful for the concerned authorities of Gilgit Baltistan and Khyber Pakhtunkhwa Province in the provision of safe drinking water to the people living in the vicinity of River Indus, Pakistan.

Watershed water policy based on a glacier water service perspective in the typical glacier basins, Western China

Abstract Taking the Yangtze River Source Basin (YRSB) and Shule River Basin (SRB) as two typical cases, the sustainability of the water resources in these two basins was evaluated using the level of water stress (LWS) from sustainable development goal 6.4.2, and the regulating effect of the glacier runoff on the LWS was quantified. From 2000 to 2030, the level of socioeconomic development in the YRSB is low, and the total water consumption is only about 0.18 × 108 m3, whereas the SRB has a relatively high level of socioeconomic development and total water consumption is about 10 × 108 m3, i.e., 50 times higher than that in the YRSB. For the aforementioned reasons, the SRB's LWS is much higher than the YRSB's, resulting in a very low sustainability of water resources. As natural assets, glaciers flow downstream in the runoff mode, so compensation at the watershed scale should be considered. In the basin, the optimal allocation of water resources is needed. At the inter-basin scale, the compensation mechanism of glacier water resources needs to be improved.

Weather prediction using traditional knowledge in cold arid high altitude region of Ladakh in India

The Union territory of Ladakh in India is a cold arid high altitude region. The subsistence nature of agriculture being practiced (by majority of farmers) in the region is solely dependent on melted glacier water. The present study was undertaken in Leh district of Ladakh to identify, prioritize and understand the traditional knowledge (TK) used by the farming community for prediction of weather. The primary data were collected from 320 households from 20 villages in Leh district from 2015 to 2020. The primary data were aided and validated by Focused Group Discussions with key informants and stakeholders working in the region such as scientists from research institutions and officials from agriculture and line departments. Farmers used combination of indicators including behavioral changes of birds and animals, change in atmospheric events and inferences drawn from Lotho (almanac) to predict weather. Migration pattern of birds was the most ancient, common and widely prevalent TK used for prediction of onset and extent of snowfall and winter season by farmers. Building of nest by birds on poplar tree (Poplus sp.) at different heights and directions was used to predict temperatures in the forthcoming summer season. The duration of hibernation of Himalayan marmots (Marmota himalayana) was an indication of duration of snowfall and winter temperatures. Timing and extent of precipitation (rainfall and snowfall) was used to predict the distribution of snowfall and winter temperatures. Lotho was extensively used for planning agricultural operations till a decade ago. The farming community used different TK in totality to enhance the accuracy of weather prediction. It was found that improved connectivity of the region with the mainland, introduction of modern communication technologies and decreasing dependence on agriculture as a primary livelihood option (because of the emergence of non-farm based opportunities such as services and tourism) have made the use of TK less prevalent among young generation farmers. However, the majority of the farmers expressed the need for blending TK and modern science for addressing location-specific problems.

Cryosphere changes and their impacts on regional water resources in the Chinese Altai Mountains from 2000 to 2021

The cryosphere has an important impact on regional water resources and ecosystems in the Chinese Altai Mountains and its piedmont zone. Using the latest remote-sensing datasets of cryosphere changes and combining with in-situ observation data from glacier monitoring stations and snow cover surveys, the main cryosphere elements including glaciers, snow cover, and permafrost are investigated with emphasis on their changes since 2000 and the current situation. Their water resource effects are also discussed. The results indicate that although the glaciers in the region have experienced continuous and intensive melting, mass loss has slowed because both glacier area shrinkage and thickness reduction were larger during 2000–2010 than during 2010–2021. Snow-cover water equivalent (w.e.) has increased due to obvious increases in snow depth, although snow-cover area has decreased slightly. Permafrost has been degrading. Overall, cryosphere contributions to the regional water resource are approximately 40.9% since 2000, among which snow-cover melting is the largest, contributing 37.1% to water resources in the Irtysh River Basin and significantly more in the mountainous sub-basins with increased snowfall. Glacier melting contributes 2.9%∼3.4%, lower than earlier estimations of 3.4%∼3.6% for the late 20th century. Permafrost thaw caused by active layer thickening contributes approximately 0.59%. Meteorological data shows a warming and wetting trend, but summer temperature has a much lower increase rate and a slowing increase trend after 2013. Moreover, snowfall frequency has increased. In the future, glacier water resource contribution will continue to decrease, but the water resource effects of snow-cover melting and permafrost degradation would increase.

Long-term hydrological behavior of an Alpine glacier

Alpine glaciers are shrinking at a relentless pace, as an effect of global warming. The impact of these changes in the European Alps is relevant, given the importance of this territory from both ecological and economic viewpoints. While the ubiquitous reduction of glaciers’ mass through the Alps has been reported in several studies, its effect on streamflow is less studied. In the present work, we analyzed the long streamflow time series, available since 1976, of the Careser Stream, a headwater stream emerging from the Careser Glacier, in northeastern Italy. A large amount of missing data characterizes the streamflow time series, which we filled with a high level of confidence by using a Feed Forward Deep Neural Network algorithm. We explored the influence of climatic drivers on streamflow at monthly and annual time scales. Our analysis highlighted significant changes in the timing of streamflow due to the combined effect of early snow melting and a progressive reduction of the glacier’s area. The hydrological regime changed significantly with glacier water contributing to streamflow proportionally less after a tipping point identified in 1996. Projections performed by using eight bias-corrected climate models of the EURO-CORDEX collections confirmed this tendency with the complete transition of the catchment from the glacial to the nival regime by 2045 at the latest. The Deep Neural Network algorithm was very effective in filling the missing streamflow data and this offers an encouraging premise for applications in other glaciers of the Alps suffering from the same transformation.

Changes in the supply and demand potentials of China's glacier water resources in the 21st century: Spatiotemporal mismatches and combined effects

China's glacier water resources (GWRs) are not only indispensable suppliers of fresh water for humans living in large domestic areas but also affect the water supply to downstream neighbouring countries. Therefore, it is crucial to systematically evaluate the spatiotemporal (mis-) matches between the supply and demand potentials of China's GWRs and the combined supply and demand effects in the 21st century to enable regional sustainable development. To facilitate such research, in this study, we first regionalized the importance of China's GWRs in terms of the supply potential and downstream human dependence to reveal the spatial (mis-) matches between supply and demand potentials. Then, changes in the service potential of glacier meltwater and in population dynamics, as well as their temporal (mis-) matches and associated opportunities and risks, were further assessed at the river basin scale. The results showed that GWR plays an important role in 4 of 16 macroscale glacier-fed basins (i.e., Tarim, Junggar, Ili, and Zangxi) and 11 of 37 subbasins within the China region due to higher supply potential and demand potential in those basins. The importance of China's GWRs increases dramatically when taking the demand potential of downstream countries into account, especially in the Ganges and Indus river basins. The peaks in meltwater runoff from the most glacierized basins of the eastern Tianshan Mountains, eastern Qilian Mountains, and southeastern Tibetan Plateau of China occur slightly earlier than the projected peak population (around 2030) under the mid-range Shared Socioeconomic Pathway (SSP245), leading to a compound risk in terms of decreasing meltwater supply and increasing human dependence at the end of the 2020s. However, the peak meltwater is expected to occur later than the peak population in the Tarim, Qiangtang Plateau, and Qaidam basins. The opportunities offered by the increase in meltwater can relieve the water resource pressure for those populations under water-stressed conditions. Greater attention should also be paid to water shortage risks in the transboundary river basins, especially in the Indus and Ganges basins, because the peak meltwater within China is generally expected to occur sooner than the projected peak population of downstream countries. This study provides an effective planning and decision-making basis for the full utilization of China's GWRs and adaptation when glacier runoff declines.

A Review of the Current State of Microplastic Pollution in South Asian Countries

Microplastic contamination has become a concerning topic of study in recent decades. This review discusses the development of microplastic pollution based on a selection of South Asian countries consisting of Bangladesh, Iran, Philippines, Thailand, India, Indonesia, and Vietnam. The condition of microplastic pollution related to the abundance of microplastic found in various environments as well as the presence of microplastics in food and the air, is covered in this review. Several reports found that drinking water sourced from taps was found to have about 83% of microplastic particles in the year 2017 based on results from 14 nations, and in the year 2018, 260 bodies of water for human consumption in 11 countries were found to have about 93% of microplastic particles. Micro debris pollution in seas and oceans worldwide is predicted to be at an amount of 236,000 metric tons based on a statistical report. A mean value of 30 micro debris per liter of glacier water was recovered from the top of Mount Everest, whereas about 2200 small particles per liter were discovered in the deep waters of the Mariana Trench. The main environments that are severely microplastic-contaminated are water-based places such as rivers, estuaries, and beaches. The presence of microplastics in food items, such as tea bags, sugar, shrimp paste, and salt packets, has been reported. In terms of impacts on the environment, microplastic contamination includes the ingestion of microplastics by aquatic creatures in water environments. The impacts on terrestrial environments relate to microplastics sinking into the soil, leading to the alteration of the physicochemical parameters of soil. Meanwhile, the impacts on the atmospheric environment include the settling of microplastics on the external bodies of animals and humans.

Examining the variability of rock glacier meltwater in space and time in high-elevation environments of Utah, United States

Rock glaciers are common geomorphic features in alpine landscapes and comprise a potentially significant but poorly quantified water resource. This project focused on three complementary questions germane to rock glacier hydrology: 1) Does the composition of rock glacier meltwater vary from year to year? 2) How dependent is the composition of rock glacier meltwater on lithology? And 3) How does the presence of rock glaciers in a catchment change stream water chemistry? To address these questions, we deployed automated samplers to collect water from late June through mid-October 2022 in two rock-glacierized mountain ranges in Utah, United States characterized by different lithologies. In the Uinta Mountains of northern Utah, where bedrock is predominantly quartzite, water was collected at springs discharging from two rock glaciers previously shown to release water in late summer sourced from internal ice. In the La Sal Mountains of southeastern Utah, where trachyte bedrock is widespread, water was collected at a rock glacier spring, along the main stream in a watershed containing multiple rock glaciers, and from a stream in a watershed where rock glaciers are absent. Precipitation was also collected, and data loggers for water temperature and electric conductivity were deployed. Water samples were analyzed for stable isotopes with cavity ring-down spectroscopy and hydrochemistry with ICP-MS. Our data show that water discharging from rock glaciers in the Uinta Mountains exhibits a shift from a snowmelt source to an internal ice source over the course of the melt season that is consistent from year to year. We also found that the chemistry of rock glacier water in the two study areas is notably different in ways that can be linked back to their contrasting bedrock types. Finally, in the La Sal Mountains, the properties of water along the main stream in a rock-glacierized basin resemble the properties of water discharging from rock glaciers, and strongly contrast with the water in a catchment lacking rock glaciers. Collectively these results underscore the role of rock glaciers as an agent influencing the hydrochemistry of water in high-elevation stream systems.

Glacier Surface Heatwaves Over the Tibetan Plateau

AbstractThe Tibetan Plateau (TP) has warmed at a rate twice the global average and presents unique warming patterns in surface temperature changes. However, key characteristics of glacier surface heatwave duration and intensity over the TP during the present extreme warming period are still unknown. In this study, we show that surface temperatures in glacial regions of the TP (0.37 ± 0.10°C per decade) have increased faster than those in non‐glacial areas (0.29 ± 0.05°C per decade) between 2001 and 2020. Moreover, the duration (5.3 ± 3.2 days per decade) and cumulative intensity (24.9 ± 16.3 days °C per decade) of glacier surface heatwaves have increased significantly during autumn. Our results demonstrate an elevation dependence to these key warming characteristics, which we also suggest are associated with extreme glacier mass loss. Here, we highlight potential threats to the sustainability of glacier water resources and increasing risk of glacier related hazards at the “roof of the world.”

Contribution of rock glacier discharge to late summer and fall streamflow in the Uinta Mountains, Utah, USA

Abstract. Water draining from rock glaciers in the Uinta Mountains of Utah (USA) was analyzed and compared with samples of groundwater and water from the primary stream in a representative 5000 ha drainage. Rock glacier water resembles snowmelt in the early summer but evolves to higher values of d-excess and greatly elevated Ca and Mg content as the melt season progresses. This pattern is consistent with models describing a transition from snowmelt to melting of seasonal ice to melting of perennial ice in the rock glacier interior in late summer and fall. Water derived from this internal ice appears to have been the source of ∼25 % of the streamflow in this study area during September of 2021. This result emphasizes the significant role that rock glaciers can play in the hydrology of high-elevation watersheds, particularly in summers following a winter with below-average snowpack.

Methods for assessing hydrological and geoecological risks based on modelling

This study is intended for decision-makers in the field of water resources use (irrigation and hydropower) and for emergency prevention authorities. Another problem remains intensive technogenic pollution of the environment, including water bodies, and one of the main tasks in the conditions of technogenesis is the development of predictive models for the migration of polluting chemical elements and substances in the environment. To calculate the runoff of the river the HBV3-ETH9 hydrological model and the CMIP5 RCP4.5 and RCP8.5 climate projections were used, according to which the air temperature is expected to increase by 2.3 and 4.3 °C, respectively, in annual precipitation - by 10% of the norm. In the period 2023-2080, a gradual increase in annual runoff is expected by 9-23%, and according to the extreme scenario, by 9-36% of the norm, which is associated with intensive glacier water loss, seasonal snowmelt and rainfall. In the future, the passage of two flood peaks (in June and July) is possible. The increase in water content in April and May will contribute to increased mudflow and flood activity.

Updating Inventory, Deformation, and Development Characteristics of Landslides in Hunza Valley, NW Karakoram, Pakistan by SBAS-InSAR

The Hunza Valley, in the northwestern Karakoram Mountains, North Pakistan, is a typical region with many towns and villages, and a dense population and is prone to landslides. The present study completed landslide identification, updating a comprehensive landslide inventory and analysis. First, the ground surface deformation was detected in the Hunza Valley by SBAS-InSAR from ascending and descending datasets, respectively. Then, the locations and boundaries were interpreted and delineated, and a comprehensive inventory of 118 landslides, including the 53 most recent InSAR identified active landslides and 65 landslides cited from the literature, was completed. This study firstly named all 118 landslides, considering the demand for globally intensive research and hazard mitigation. Finally, the deformation, spatial–topographic development, and distribution characteristics in the Hunza Valley scale and three large significant landslides were analyzed. Information on 72 reported landslides was used to construct an empirical power law relationship linking landslide area (AL) to volume (VL) (VL = 0.067 × AL1.351), and this formula predicted the volume of 118 landslides in this study. We discovered that the landslides from the literature, which were interpreted from optical images, had lower levels of velocity, area, elevation, and height. The SBAS-InSAR-detected active landslide was characterized by higher velocity, larger area, higher elevation, larger slope gradient, larger NDVI (normalized difference vegetation index), and greater height. The melting glacier water and rainfall infiltration from cracks on the landslide’s upper part may promote the action of a push from gravity on the upper part. Simultaneously, the coupling of actions from river erosion and active tectonics could have an impact on the stability of the slope toe. The up-to-date comprehensive identification and understanding of the characteristics and mechanism of landslide development in this study provide a reference for the next step in landslide disaster prevention and risk assessment.

Study on the Ablation of the Glacier Covered by Mineral Dust in Alpine Regions

Glaciers, known as solid reservoirs, are important water supply sources in northwest China. In this paper, mineral dust collected from a Chinese alpine mining area (Beizhan iron mine) and an ice cube (with a 225 cm2 section and a volume of 1000 mL) were employed via a delicate physical experiment to study the ablation of glaciers covered by mineral dust in alpine regions. After that, the ablation mechanism was revealed using the energy conservation theory. The main findings are as follows: (1) When the solar radiation intensity is 993 W/m2, the glacier ablation rate increases by 13.9% (from 282 to 321.2 mL/h) as the mineral dust coverage rate increases from 0% to 42.7%. (2) When the mineral dust coverage rate remains at 30%, the glacier ablation rate increases by 11.6% (from 291.8 to 325.78 mL/h) as the solar radiation intensity increases from 1007 to 1153 W/m2. (3) When the solar radiation intensity and mineral dust coverage rate remain unchanged, the ablation rate of the glacier covered by the mineral dust inversely increases with the dust particle size. The ablation rates of the particle size gradings C, B, and A (the dust particle sizes of gradings A, B, and C in 0.0375–0.075 mm, 0.075–0.125 mm, and 0.125–0.25 mm accounted for 5%:50%:45%, 30%:40%:30%, and 70%:30%:0%, respectively) were 293.4, 301.2, and 305.6 mL /h, respectively, and the corresponding ablation rates increased by 2.7% and 1.5%. (4) The smaller the average particle size of the mineral dust, the greater the contribution to the ablation rate; a 1 °C temperature increase to the glacier ablation rate is equivalent to 29.1%, 33.6%, and 40.6% increases in dust coverage for particle size classes C, B, and A. (5) The mineral dust covering the glacier surface could not only reduce the reflectivity of the glacier surface to solar radiation but could also continuously transfer the absorbed radiant energy and its own chemical energy to the glacier body, accelerating the glacier’s meltwater speed. The findings of this paper can provide the necessary theoretical basis for mineral dust control and glacier water conservation in alpine mining areas.

Glacial Melt in the Canadian Rockies and Potential Effects on Groundwater in the Plains Region

The prevailing concern in the Western Canadian Plains is that glaciers from the eastern Canadian Rocky Mountains (CRM) are losing mass, thus affecting groundwater recharge in the Plains. The generally accepted hypothesis is that those glaciers are the geological source of groundwater for aquifers located in the Plains. The aquifers located in this region, close to the eastern part of the Rockies, represent a major source of water for the local population. It is believed that aquifer recharge originates as infiltration from snowmelt and ice in the Front Ranges of the eastern Rockies. A growing concern relates to the significant glacier melt estimated from glacier mass balances, which indicate that glaciers and ice fields have experienced considerable mass losses over the last 15 years, between 1 and 5 km3 per year, thus reducing recharge. However, deep groundwater flow under melting glacier conditions in mountainous regions is poorly understood. In this study, three 2D numerical hydrogeological models are built in order to simulate the groundwater flow under the glaciers from the Main and Front Ranges of the CRM and the Plains in the province of Alberta, Canada. Numerical results and a sensitivity analysis indicate that up to three different regional groundwater-flow systems are present in the region. These systems reveal the time- and space-scales associated with the combination of a mountainous region, foothills, Plains, and deep geological conditions. Based on the current knowledge of the hydrogeology of the study area and numerical modelling results, it is highly unlikely that the melting of glaciers affects groundwater in the Plains in the immediate future. The contribution of glacier water in the eastern part of the Rockies is time-dependent with delayed groundwater flows of 1000s of years in the Front ranges, 1000s to 100,000s of years in the foothills and Foreland; and 100,000s to millions of years to the Plains, at the regional scale.

Arctic Inshore Biogeochemical Regime Influenced by Coastal Runoff and Glacial Melting (Case Study for the Templefjord, Spitsbergen)

Observations and predictions show that consequences of climate warming such as declining summer sea ice cover, melting glaciers, thawing permafrost, and increased river runoff to the Arctic Ocean will likely modify processes relevant to the freshwater and carbon budget, which in turn affect high-latitude marine ecosystems. There is a knowledge gap in terms of understanding the seasonal variability of biogeochemical characteristics in coastal environments, first of all due to a lack of winter data. More data are also needed on the biogeochemical composition of different environmental media, i.e., sediments, snow, and ice. The aim of this work was to assess the current biogeochemical regime of a fjord system exposed to coastal runoff and glacial melting and discuss the possible consequences connected with climate warming. We used data from five expeditions to the Templefjord, West Spitsbergen, obtained in different seasons (February 2011, September 2011, March 2014, June 2015, and June 2017). In all the expeditions, the distributions of dissolved oxygen, nutrients, and carbonate system parameters in the water column were studied. The principal environmental media, i.e., seawater, bottom sediments, river water, sea ice, river ice, glacier ice, and snow, were sampled. The collected data allowed us to describe seasonal dynamics in the water column and to estimate the concentrations of the parameters under study in different environmental media. Our observations revealed the glacial and river footprints in the water column biogeochemistry; the glacial influence can be traced both in summer and in winter season. The results demonstrated the significant influence of coastal runoff and melted glacier water on the carbonate system and nutrient regime in the Templefjord, and can be extrapolated to other Arctic fjord systems.

Glacial Change and Its Hydrological Response in Three Inland River Basins in the Qilian Mountains, Western China

Glacial changes have great effects on regional water security because they are an important component of glacierized basin runoff. However, these impacts have not yet been integrated and evaluated in the arid/semiarid inland river basins of western China. Based on the degree-day glacier model, glacier changes and their hydrologic effects were studied in 12 subbasins in the Shiyang River basin (SYRB), Heihe River basin (HHRB) and Shule River basin (SLRB). The results showed that the glacier area of each subbasin decreased by 16.7–61.7% from 1965 to 2020. By the end of this century, the glacier areas in the three basins will be reduced by 64.4%, 72.0% and 83.4% under the three climate scenarios, and subbasin glaciers will disappear completely after the 2070s even under RCP2.6. Glacial runoff in all subbasins showed a decreasing–increasing–decreasing trend, with peak runoff experienced in 11 subbasins during 1965~2020. The contribution of glacial meltwater to total runoff in the basin ranged from 1.3% to 46.8% in the past, and it will decrease in the future due to increasing precipitation and decreasing glacial meltwater. However, the scale differences in glacier runoff are significant when aggregated over the region/basin/subbasin. This suggests that the results of large-scale generalization may be misleading for subbasin glacier water resource evaluations. Therefore, the hydrological effects of glaciers should be studied more in subbasins to provide an accurate reference for practical water resource management.

СРАВНЕНИЕ ГИДРОТЕРМИЧЕСКОЙ СТРУКТУРЫ ДВУХ ЛЕДНИКОВ ШПИЦБЕРГЕНА И ТЯНЬ-ШАНЯ ПО ДАННЫМ РАДИОЗОНДИРОВАНИЯ

The distribution of cold and temperate ice and water in polythermal glaciers significantly affects their dynamics, thermal and hydrological regime. Radar techniques are an effective remote method of their studies that allows one to determine a glacier thickness by the delay time and to estimate the water content in temperate ice and at bedrock by the intensity of reflections from the interface between cold and temperate ice and the glacier bed. In case study of Austre Gronfjordbreen in Spitsbergen and Central Tuyksu glacier in Tien Shan we consider the features of their hydrothermal structure in spring and summer periods using the data of ground-based radio-­echo sounding at frequency of 20 MHz. To estimate the relative water content, we used data from measurements of relative power reflections from the cold-temperate ice interface, at the bedrock, and from the temperate ice body. In these glaciers (Austre Gronfjordbreen and Central Tuyksu), the average thickness of cold and temperate ice is, respectively, 61 ± 6 and 27 ± 2 m, and 39 ± 4 and 20 ± 2 m, the volume of cold ice is 0.466 ± 0.005 km 3 and 0.044 ± 0.002 km 3 , and volume of temperate ice is 0.104 ± 0.001 and 0.034 ± 0.001 km 3 . Warm ice contains 2080 × 10 3 and 680 × 10 3 m 3 of water, respectively, with an average content of 2%. Measurements along the longitudinal profiles of these glaciers showed that in some parts on Austre Gronfjordbreen in the spring period the average intensity of reflections from the cold­temperate ice interface and the bedrock is −0.02 – −26.3 and −6.0 – −11.8 dB, respectively, and at the whole profile this is −13.36 dB. At Central Tuyuksu glacier the spring values are −14.5 – −32.4 and −29.6 dB, respectively. We attribute such differences of glaciers to the different water content in the temperate ice below and above these boundaries, to the specific distribution of the ice facies zones and glacial nourishment, to the different intensity of surface melting in the spring and summer periods, and to the different crevassing and velocity of glaciers.

Compilation of a glacier water resource balance sheet

Compilation of a glacier water resource balance sheet

Distribution and Control of Bacterial Community Composition in Marian Cove Surface Waters, King George Island, Antarctica during the Summer of 2018.

Marian Cove is experiencing some of the most rapid environmental changes in the Antarctic region; however, little is known about the response of bacterial communities to these changes. The main purpose of this study was to investigate the spatial variation of physical–biogeochemical–bacterial community features in the Marian Cove surface waters and the environmental parameters governing the spatial variation in the bacterial community composition during the summer of 2018. The Marian Cove surface waters are largely composed of two different characteristics of water masses: relatively low-temperature, -salinity, and -nutrient surface glacier water (named SGW) and relatively high-temperature, -salinity, and -nutrient surface Maxwell Bay water (named SMBW). The SGW bacterial communities were dominated by unclassified Cryomorphaceae, Sedimenticola, and Salibacter genera, while the SMBW bacterial communities were dominated by Sulfitobacter, Arcobacter, and Odoribacter genera. Spatial variations in bacterial community composition were mainly attributed to physical and biogeochemical characteristics, suggesting that the bacterial community composition of the Marian Cove surface waters is mainly determined by environmental characteristics. These findings provide a foundation to improve the understanding of bacterial community variations in response to a rapidly changing Marian Cove in the Antarctic.

Analysis of the Stable Isotope Ratios (18O/16O, 17O/16O, and D/H) in Glacier Water by Laser Spectrometry.

A compact isotope ratio sensor based on laser absorption spectroscopy at 2.7 μm was developed for high precision and simultaneous measurements of the D/H, 18O/16O and 17O/16O isotope ratios in glacier water. Measurements of the oxygen and hydrogen isotope ratios in glacier water demonstrate a 1σ precision of 0.3‰ for δ18O, 0.2‰ for δ17O, and 0.5‰ for δ2H, respectively. The δ values of the working standard glacier water obtained by the calibrated sensor system is basically identical to the IRMS measurement results with a very high calibration accuracy from 0.17‰ to 0.75‰. Preliminary results on the reproducibility measurements display a standard deviation of 0.13‰ for δ18O, 0.13‰ for δ17O, and 0.64‰ for δ2H, respectively.