scholarly journals Psychrophilic yeasts in glacial environments of Alpine glaciers

2008 ◽  
Vol 63 (1) ◽  
pp. 73-83 ◽  
Author(s):  
Benedetta Turchetti ◽  
Pietro Buzzini ◽  
Marta Goretti ◽  
Eva Branda ◽  
Guglielmina Diolaiuti ◽  
...  
Keyword(s):  
Alpine Glaciers ◽  
Psychrophilic Yeasts ◽  
Glacial Environments

scholarly journals Cryoconite: an efficient accumulator of radioactive fallout in glacial environments

2020 ◽  
Vol 14 (2) ◽  
pp. 657-672 ◽  
Author(s):  
Giovanni Baccolo ◽  
Edyta Łokas ◽  
Paweł Gaca ◽  
Dario Massabò ◽  
Roberto Ambrosini ◽  
...  
Keyword(s):  
Global Fallout ◽  
Artificial Radioactivity ◽  
Chernobyl Fallout ◽  
Alpine Glaciers ◽  
Activity Ratios ◽  
Natural And Artificial Radioactivity ◽  
Glacial Environments ◽  
Radioactive Species ◽  
Ideal Matrix

Abstract. Cryoconite is rich in natural and artificial radioactivity, but a discussion about its ability to accumulate radionuclides is lacking. A characterization of cryoconite from two Alpine glaciers is presented here. Results confirm that cryoconite is significantly more radioactive than the matrices usually adopted for the environmental monitoring of radioactivity, such as lichens and mosses, with activity concentrations exceeding 10 000 Bq kg−1 for single radionuclides. This makes cryoconite an ideal matrix to investigate the deposition and occurrence of radioactive species in glacial environments. In addition, cryoconite can be used to track environmental radioactivity sources. We have exploited atomic and activity ratios of artificial radionuclides to identify the sources of the anthropogenic radioactivity accumulated in our samples. The signature of cryoconite from different Alpine glaciers is compatible with the stratospheric global fallout and Chernobyl accident products. Differences are found when considering other geographic contexts. A comparison with data from literature shows that Alpine cryoconite is strongly influenced by the Chernobyl fallout, while cryoconite from other regions is more impacted by events such as nuclear test explosions and satellite reentries. To explain the accumulation of radionuclides in cryoconite, the glacial environment as a whole must be considered, and particularly the interaction between ice, meltwater, cryoconite and atmospheric deposition. We hypothesize that the impurities originally preserved into ice and mobilized with meltwater during summer, including radionuclides, are accumulated in cryoconite because of their affinity for organic matter, which is abundant in cryoconite. In relation to these processes, we have explored the possibility of exploiting radioactivity to date cryoconite.

Focus on Thermokarst Lakes in Indian Himalaya: Inception and Implication under Warming Climate

2020 ◽  
Vol 6 (2) ◽  
pp. 59-69
Author(s):  
Pratima Pandey ◽  
S. Nawaz Ali ◽  
Vikram Sharma ◽  
Prashant K. Champati Ray
Keyword(s):  
Western Himalaya ◽  
High Mountain ◽  
Thermokarst Lakes ◽  
Glacial Environments ◽  
Global Warming Scenario ◽  
Scientific Attention ◽  
Topographic Depressions ◽  
Permafrost Thawing ◽  
The Impact ◽  
Thaw Lakes

Thermokarst (Thaw) lakes are landforms found in topographic depressions created by thawing ground ice in permafrost zones. They play an important role in the regulation of climatic functions. These lakes are a manifestation of warming surface temperatures that accelerates the ice-rich permafrost to degrade by creating marshy hollows/ponds. In the current global warming scenario, the thermokarst lakes in the high mountain regions (Himalaya) are expected to grow further. This accelerate permafrost thawing which will affect the carbon cycle, hydrology and local ecosystems. This phenomenon has attracted huge scientific attention because it has led to a rapid mass change of glaciers in the region, including extensive changes occurring on peri-glacial environments. The most striking fact is the release of an enormous amount of greenhouse gases, including methane, carbon dioxide and nitrous oxide that is locked in these lakes. The present study delves into the thermokarst lakes in the upper reaches of Chandra Valley and Western Himalaya. The study also aims at designating the impact of their changes on the ecosystem, particularly their influence on the atmospheric greenhouse gas concentrations.

scholarly journals New glacier evidence for ice-free summits during the life of the Tyrolean Iceman

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Pascal Bohleber ◽  
Margit Schwikowski ◽  
Martin Stocker-Waldhuber ◽  
Ling Fang ◽  
Andrea Fischer
Keyword(s):  
Elevation Gradient ◽  
Ice Age ◽  
Detailed Knowledge ◽  
New Approach ◽  
Radiocarbon Age ◽  
Alpine Glaciers ◽  
The Alps ◽  
Tyrolean Iceman ◽  
High Elevations ◽  
Age Constraints

AbstractDetailed knowledge of Holocene climate and glaciers dynamics is essential for sustainable development in warming mountain regions. Yet information about Holocene glacier coverage in the Alps before the Little Ice Age stems mostly from studying advances of glacier tongues at lower elevations. Here we present a new approach to reconstructing past glacier low stands and ice-free conditions by assessing and dating the oldest ice preserved at high elevations. A previously unexplored ice dome at Weißseespitze summit (3500 m), near where the “Tyrolean Iceman” was found, offers almost ideal conditions for preserving the original ice formed at the site. The glaciological settings and state-of-the-art micro-radiocarbon age constraints indicate that the summit has been glaciated for about 5900 years. In combination with known maximum ages of other high Alpine glaciers, we present evidence for an elevation gradient of neoglaciation onset. It reveals that in the Alps only the highest elevation sites remained ice-covered throughout the Holocene. Just before the life of the Iceman, high Alpine summits were emerging from nearly ice-free conditions, during the start of a Mid-Holocene neoglaciation. We demonstrate that, under specific circumstances, the old ice at the base of high Alpine glaciers is a sensitive archive of glacier change. However, under current melt rates the archive at Weißseespitze and at similar locations will be lost within the next two decades.

Unravelling the moisture sources of the Alpine glaciers using tunnel valleys as constraints

Terra Nova ◽  
2016 ◽  
Vol 28 (3) ◽  
pp. 202-211 ◽  
Author(s):  
Regina Reber ◽  
Fritz Schlunegger
Keyword(s):  
Moisture Sources ◽  
Alpine Glaciers

scholarly journals Measurements of Ablation and Heat Balance On Alpine Glaciers: With some remarks on the cause of glacier recession in the Alps

1955 ◽  
Vol 2 (17) ◽  
pp. 497-501 ◽  
Author(s):  
H. Hoinkes
Keyword(s):  
Latent Heat ◽  
Heat Balance ◽  
Eastern Alps ◽  
Short Wave ◽  
Wave Radiation ◽  
Perfect Agreement ◽  
Glacier Recession ◽  
A Value ◽  
Alpine Glaciers ◽  
Summer Temperatures

AbstractMeasurements of heat balance and ablation on glaciers of the Eastern Alps carried out during a total of 45 days since the summer of 1950 indicate that in flat glaciated areas at approximately 3000 m. above sea level 81 to 84 per cent of the energy causing ablation is supplied by short wave radiation from the sun and sky. Only 16 to 19 per cent come from the air in the form of actual and latent heat. On glacier tongues at altitudes of approximately 2300 m. the percentage of ablation caused by radiation is only 58 to 65 per cent. This is primarily the result of the shortened duration of sunshine in the deeper valleys. The supply of perceptible and latent heat from the air can, at most, reach a value of 15 to 30 per cent on glacier tongues. Evaporation from the ice and heat supply by liquid precipitation are negligible during the normal ablation period (June till September).It is to be expected therefore that the alpine glaciers will primarily react to variations of radiation and albedo during the months of June to September. The effects of changing summer temperatures are considered insufficient to cause the vast changes of the ice-cover. The variations of the duration of summer sunshine and the number of days with snowfall as a rough indication of albedo, respectively, are in perfect agreement with the behaviour of alpine glaciers during the last sixty years.

scholarly journals Ancient Alpine Glaciers of the Sierra Costa Mountains in California

1900 ◽  
Vol 8 (1) ◽  
pp. 42-57 ◽  
Author(s):  
Oscar H. Hershey
Keyword(s):  
Alpine Glaciers

scholarly journals Ground Data Inputs To Image Processing for Estimating Terrain Characteristics for Glacio-Hydrological Analysis

1987 ◽  
Vol 9 ◽  
pp. 45-49 ◽  
Author(s):  
M.J. Clark ◽  
A.M. Gurnell ◽  
P.J. Hancock
Keyword(s):  
Remote Sensing ◽  
Image Processing ◽  
Satellite Imagery ◽  
Geometric Correction ◽  
Data Set ◽  
Glacial Environments ◽  
Methodological Problems ◽  
Terrain Characteristics ◽  
Radiometric Data

Remote-sensing research in glacial and pro-glacial environments raises several methodological problems relating to the handling of ground and satellite radiometric data. An evaluation is undertaken of the use of ground radiometry to elucidate properties of relevant surface types in order to interpret satellite imagery. It identifies the influence that geometric correction and re-sampling have on the radiometric purity of the resulting data set. Methodological problems inherent in deriving catchment terrain characteristics are discussed with reference to currently glacierized and pro-glacial zones of south-western Switzerland.

scholarly journals Recent fluctuations of glaciers in Valtellina (Italian Alps) and climatic variations

1992 ◽  
Vol 38 (129) ◽  
pp. 309-313 ◽  
Author(s):  
Manuela Pelfini ◽  
Claudio Smiraglia
Keyword(s):  
Temperature Fluctuations ◽  
Winter Precipitation ◽  
Meteorological Station ◽  
Summer Temperature ◽  
Italian Alps ◽  
Climatic Variations ◽  
Alpine Glaciers ◽  
The Mean

AbstractValtellina, located in the Italian Alps of Lombardy, is extensively glaciated. Since 1925, terminal variations of the glaciers have been recorded. By analysing a significant sample of valley glaciers, we have recognized a rapid retreat of the termini which occurred between 1925 and the early 1970s. A period of advance followed, which stopped in the second half of the 1980s. The mean summer-temperature fluctuations at the meteorological station of Sondrio at the centre of Valtellina, show that the period 1925–52 was very warm, and then the temperatures dropped. The most intense winter precipitation occurred in the period 1925–37. The behaviour of these glaciers is similar to that of other Alpine glaciers, although time of response may be different.

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