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The paper discussed the influence of the forms of sediment accumulation on the surface of glaciers on their chemical and physicochemical properties. The materials sampled from the surface of five glaciers of the Svalbard Archipelago was analyzed. We studied such forms of sediment accumulation as dirt cones - the ice core covered with sediments and cryoconite holes - hollows on the glacier surface containing cryoconite material. Parameters such as total organic carbon content, microbiological activity, pH, the content of mobile forms of potassium and phosphorus, and concentrations of heavy and trace metals were studied. Also, mesomorphological studies were carried out and the polydisperse composition of the sediments was determined. According to the results of this work, it was found that the content of organic carbon in the material selected from dirt cones and cryoconite holes can be up to 2.5%, but the content of clay particles in it is mainly at the 10–15% level. Potassium concentrations are up to 250 mg/kg, and phosphorus is up to 800 mg/kg. The content of metals is typical or lower than in the previously published data. The main influence on the chemical composition of materials has a geographical factor of the sampling site, rather than the form of material accumulation. [ABSTRACT FROM AUTHOR]

The surface of mountain glaciers is a place of accumulation of various biogenic organomineral and mineral compounds. As a result of intensive mass deglaciation of glaciers due to climate change and anthropogenic activity, this material can significantly affect the transformation of the landscape in the periglacial zone. Thus, this work considers the contamination of the surface of the Arctic, Antarctic, and Caucasian glaciers by priority pollutants. Atomic absorption spectroscopy was used to analyze trace elements (Cu, Zn, Ni, Cd, Pb) from cryoconite deposits. It was revealed that the cryoconite dust on the Ray-Iz glacier (Polar Urals) has a high level of nickel contamination, which comes to the glacier from local rock materials as a result of their weathering. The lowest concentrations of trace elements are found in one of the Arctic plots located at Mushketov and Aldegonda glaciers, the Caucasus, and the Antarctic, which is due to their relatively low content in the composition of rocks and the relatively low contribution of long-range transport of matter to the polar regions. Contamination of moraine sediments in the periglacial zone can make a significant contribution to the formation of the soil cover of these territories, the pollution of water bodies near the glacier, as well as affect the quality of life of the people living in the immediate vicinity of the mountain areas. [ABSTRACT FROM AUTHOR]

Research into sediment provenance identification in Antarctica is emerging as a relevant field of study, providing a unique insight into understanding geomorphological processes in extreme climatic environments. This study focusses on the mechanisms of sediment redistribution in the catchment of the Korabelny Stream, located at the western end of the Bellingshausen Ice Dome on King George Island (Shetland Islands). The catchment area of the stream covers 2.83 km2, with 1.17 km2 under the glacier. Two main sediment sources have been identified: a) the glacierized part, extending along the glacier edge and represented by a complex of moraine deposits lacking protective vegetation cover, along with part of the catchment under the glacier; b) the periglacial part, occupying territory with permafrost and a thin loose cover unevenly protected by early successional vegetation. We combine a tracer-based fingerprinting technique, sediment delivery estimates based on sediment flow connectivity index and geomorphological mapping to quantify the sources contribution to sediment yield. The proportional contribution of the glacierized part was 60–66 % of the total sediment yield based on two independent methods, suggesting the reliability of the results. It is noteworthy that sediment transport from the glacierized part exceeds that from the periglacial part. However, a significant portion of the sediment is redeposited in temporary reservoirs formed along the glacier edge and Lake Mesyats, located in the central part of the Korabelny Stream catchment. The main factor determining sediment yield in the catchment is the water reserves in snow at the beginning of the ablation season. In years when water reserves in snow significantly exceed long-term average values, such as observed in the austral summer of 2014–2015 when study was conducted, sediment yield was low. This is attributed to the faster melting of ice on the glacier compared to snow, due to differences in albedo. • First time, assessed sediment sources in small Maritime Antarctica catchment. • Two independent methods used to determine proglacial and periglacial contributions. • Proglacial part contributes significantly more to sediment runoff. • The higher snow water reserves at ablation start the lower proglacial sediment runoff. [ABSTRACT FROM AUTHOR]

Abstract: The physics of water temperature change along a glacial water stream and its relation to ice melting rate on the channel walls are examined. The heat balance equation is based on the principles of energy conservation and an empirical relation of heat exchange between ice and flowing water. It is shown that the temperature of water exponentially approaches a nonzero value as flowing along a glacial channel. The channel meandering and noncircular cross-section were also taken into account. Typical values of the equilibrium water temperature are hundredths to a tenth of a degree depending on the channel size and slope, but the temperature can drastically increase when the channel has sediments. We compared our calculations to 1) a series of experiments with an artificial channel in ice and 2) data obtained from measurements at the Caucasus and Patagonia glaciers. [Copyright &y& Elsevier]

Enormous deglaciation in the polar and mountainous regions of the Earth is associated not only with large-scale climatic changes but also with the global transfer of black carbon (BC) microparticles, which accumulate on the surface of glaciers and lead to changes in albedo and the rate of degradation of ice. BC is the product of an incomplete combustion of fossil fuels, volcanic eruptions, and wildfires. The accumulation of organogenic microparticles leads to the formation of cryoconites, which are dust made of a combination of small rock particles and the result of anthropogenic activities (fossil fuel combustion) that play a special role in deglaciation. Here, we describe the content of trace metals and nutrients in accumulation of the BC from glaciers of Fildes Peninsula, King George Island, Western Antarctica. The analysis of trace metals concentrations showed that most of the studied elements (Cr, Pb, Zn, Ni) have a volcanic origin; at the same time, Cd and Cu have been accumulated as a result of anthropogenic activity. The content of nutrients in BC are most similar with Technosols, which forms near the scientific station at King George Island. The particles of BC can be translocated into organisms, which could pose a significant risk for living organisms and humans. [ABSTRACT FROM AUTHOR]

Glacier mass balance measurements, reconstructions and modeling are the precondition for assessing glacier sensitivity to regional climatic fluctuations. This paper presents new glaciological and geodetic mass balance data of Austre Grønfjordbreen located in the western part of Nordenskiöld Land in Central Spitsbergen. The average annual mass balance from 2014 to 2019 was −1.59 m w.e. The geodetic mass balance from 2008 to 2017 was −1.34 m w.e. The mass balance was also reconstructed by the temperature-index model from 2006 to 2020 and by spatially-distributed energy-balance models for 2011–2015 and 2019. We found a cumulative mass balance of −21.62 m w.e. over 2006–2020. The calculated mass-balance sensitivity to temperature was −1.04 m w.e. °C−1, which corresponds to the highest glacier mass balance sensitivity among Svalbard glaciers. Sensitivity to precipitation change was 0.10 m w.e. for a 10% increase in precipitation throughout the balance year. Comparing the results of the current study with other glacier mass balance assessments in Svalbard, we found that Austre Grønfjordbreen loses mass most rapidly due to its location, which is mostly influenced by the warm West Spitsbergen Current, small area and low elevation range. [ABSTRACT FROM AUTHOR]

In ice-free surfaces of King George Island (South Shetland Islands, Maritime Antarctica) themain formations along topographic chronosequences consist of weathered volcanic rockoutcrops, marine platforms, deposits of glacial materials such as moraines, andpresent day beaches. In relation with recent glacier retreat processes of sedimentredistribution in unstable paraglacial environments are highly active in the area. Togetherwith soil particles the mobilization of associated soil organic carbon (SOC) can befurther enhanced under conditions of climate change by melting snow and ice. InFebruary 2015 we conducted a selective sampling of reference sites on marineplatforms and moraines to be compared with surface sediments recently deposited inlakes on the platforms and in the proglacial environment of the Bellingshausen IceDome. During a 15 days field campaign funded by IAEA INT5153 project wecollected soil and sediment profiles and lake surface sediments to assess if there weredifferences between old marine platforms and contemporary moraines in their FRNs andSOC signatures, as both proxies have been found to be effective tracers of recentglacier retreat in other polar environments. The reference samples on the platformswere characterized by relatively slightly higher contents of sand (> 50%) thansilt fraction and low clay contents (< 5%) accompanied by SOC contents rangingbetween 1 and 3.5 % and FRNs values of 3.5 Bq kg−1for 137Cs and of 8 Bq kg−1for210Pbex. In contrast, on moraines the dominant grain size was silt (> 70 %), theSOC contents were below 0.5% and FRNs were much lower than in platforms soilswith activities of 137Cs below the detection limit and of 210Pbex less than 5 Bqkg−1. The surface sediments accumulated in the proglacial lakes were enrichedin sand (> 80 %) while in the platform lake they were mainly silt (> 70 %) andclay fractions reached up to 12 %. The sediments of the platform lake had highSOC contents (6.3 %) but the proglacial lakes had negligible values (< 0.1%).FRNs were not detected at the proglacial Upper Lake where the source materials aremoraine and fresh glacier materials. However, the low FRNs activities found at theLower Lake are because its headwaters also comprise soils developed on marineplatforms. Our results regarding contents of FRNs and SOC in the source areas and thesediments accumulated in the lakes, reflect a clear link on the provenance of sediments.The differences of grain size in lake sediments might suggest a relatively moreenergetic runoff in the proglacial lakes related to melting snow and ice directlyfrom glacier in comparison with that on platforms. These results are consistentwith a highly dynamic environment and in which soil and sediment particles areredistributed along the sediment cascade system in ice-free areas of Maritime Antarctica. [ABSTRACT FROM AUTHOR]