scholarly journals Glacier change over the last century, Caucasus Mountains, Georgia, observed from old topographical maps, Landsat and ASTER satellite imagery

2016 ◽  
Vol 10 (2) ◽  
pp. 713-725 ◽  
Author(s):  
Levan G. Tielidze

Abstract. Changes in the area and number of glaciers in the Georgian Caucasus Mountains were examined over the last century, by comparing recent Landsat and ASTER images (2014) with older topographical maps (1911, 1960) along with middle and high mountain meteorological stations data. Total glacier area decreased by 8.1 ± 1.8 % (0.2 ± 0.04 % yr−1) or by 49.9 ± 10.6 km2 from 613.6 ± 9.8 km2 to 563.7 ± 11.3 km2 during 1911–1960, while the number of glaciers increased from 515 to 786. During 1960–2014, the total ice area decreased by 36.9 ± 2.2 % (0.7 ± 0.04 % yr−1) or by 207.9 ± 9.8 km2 from 563.7 ± 11.3 km2 to 355.8 ± 8.3 km2, while glacier numbers decreased from 786 to 637. In total, the area of Georgia glaciers reduced by 42.0 ± 2.0 % (0.4 ± 0.02 % yr−1) between 1911 and 2014. The eastern Caucasus section had the highest retreat rate of 67.3 ± 2.0 % (0.7 ± 0.02 % yr−1) over this period, while the central part of Georgian Caucasus had the lowest, 34.6 ± 1.8 % (0.3 ± 0.01 % yr−1), with the western Caucasus intermediate at 42.8 ± 2.7 % (0.4 ± 0.03 % yr−1).

Author(s):  
Zalina V. Sosranova ◽  
Zalina M. Basieva

The article examines the scale and methods of the anti-Russian military-political activity of British emissaries in the Western Caucasus in the first half of the 19th century. The scientific novelty lies in the fact that for the first time in the work the intelligence activity of British “traveling” agents in the Western Caucasus is subjected to a special study, as an independent, gaining strength way of fighting in international contradictions for the Caucasus. The relevance of the topic of the proposed article seems to us indisputable due to the incompleteness of international rivalry and the eternal Eastern question. Russian Empire in the late 20s — early 30s XIX century. took possession of all legal rights to the North-West Caucasus and outlets to the Black Sea. With its confident military successes and new territorial accessions, Russia threw a serious challenge to the European powers, and especially England, the dominant power on the European continent at that time. One of the most important tasks of England is to nullify all the achievements of Russia in Turkey and prevent its consolidation in the territory of the Western Caucasus. England, adhering to the favorite method of “raking in the heat with someone else’s hands”, and in Circassia is testing its effectiveness. Since the 30s. XIX century. Numerous British agents flooded the Caucasus, turning the Circassians against Russia. The Black Sea coast of the Caucasus has become a place of uninterrupted supply of weapons to the mountaineers. As a result of the work, the author comes to the conclusion that the sources considered in the work can represent a scientific basis for confirming the involvement of Britain in anti-Russian agitation in the Western Caucasus. The uninterrupted supply of weapons to the highlanders organized by British agents helped to maintain military tension and a fighting spirit in Circassia.


2016 ◽  
Vol 62 (233) ◽  
pp. 579-592 ◽  
Author(s):  
LINGHONG KE ◽  
XIAOLI DING ◽  
LEI ZHANG ◽  
JUN HU ◽  
C. K. SHUM ◽  
...  

ABSTRACTGlacier change has been recognized as an important climate variable due to its sensitive response to climate change. Although there are a large number of glaciers distributed over the southeastern Qinghai–Tibetan Plateau, the region is poorly represented in glacier databases due to seasonal snow cover and frequent cloud cover. Here, we present an improved glacier inventory for this region by combining Landsat observations acquired over 2011–13 (Landsat 8/OLI and Landsat TM/ETM+), coherence images from Advanced Land Observing Satellite Phased Array type L-band Synthetic Aperture Radar images and the Shuttle Radar Topography Mission (SRTM) DEM. We present a semi-automated scheme for integrating observations from multi-temporal Landsat scenes to mitigate cloud obscuration. Further, the clean-ice observations, together with coherence information, slope constraints, vegetation cover and water classification information extracted from the Landsat scenes, are integrated to determine the debris-covered glacier area. After manual editing, we derive a new glacier inventory containing 6892 glaciers >0.02 km2, covering a total area of 6566 ± 197 km2. This new glacier inventory indicates gross overestimation in glacier area (over 30%) in previously published glacier inventories, and reveals various spatial characteristics of glaciers in the region. Our inventory can be used as a baseline dataset for future studies including glacier change assessment.


2017 ◽  
Author(s):  
Levan G. Tielidze ◽  
Roger D. Wheate ◽  
Stanislav S. Kutuzov ◽  
Kate Doyle ◽  
Ivan I. Lavrentiev

Abstract. Surpaglacial debris cover plays an increasingly important role impacting on glacier ablation, while there have been limited recent studies for the assessment of debris covered glaciers in the Greater Caucasus mountains. We selected 559 glaciers according to the sections and macroslopes in the Greater Caucasus main watershed range and the Elbrus massif to assess supraglacial debris cover (SDC) for the years 1986, 2000 and 2014. Landsat (Landsat 5 TM, Landsat 7 ETM+, Landsat 8 OLI) and SPOT satellite imagery were analysed to generate glacier outlines using manual and semi-automated methods, along with slope information from a Digital Elevation Model. The study shows there is greater SDC area on the northern than the southern macroslope, and more in the eastern section than the western and central. In 1986-2000-2014, the SDC area increased from 6.4 %-8.2 %-19.4 % on the northern macroslope (apart from the eastern Greater Caucasus section), while on the southern macroslope, SDC increased from 4.0 %-4.9 %-9.2 %. Overall, debris covered glacier numbers increased from 122-143-172 (1986-2000-2014) for 559 selected glaciers. Despite the total glacier area decrease, the SDC glacier area and numbers increased as a function of slope inclination, aspect, glacier morphological type, Little Ice Age (LIA) moraines, rock structure and elevation. The datasets are available for public download at https://doi.pangaea.de/10.1594/PANGAEA.880147.


2019 ◽  
Vol 46 (1) ◽  
pp. 51-57 ◽  
Author(s):  
L. V. Razumovskii ◽  
V. L. Razumovskii

To analyze processes that may lead to long-term changes in pH, lake sediments from five small lakes in the Western and Central Caucasus were studied according to diatomaceous complexes from sediment cores. A proprietary principle of hydrological parameter unification was used to reconstruct numerical pH values. In isotopic dating experiments, a series of numerical pH values for 2000–130 years were generated for the lakes. These data indicate an absence of noticeable changes in pH in the lakes of the Western Caucasus and alkalization processes in the lakes of the Central Caucasus.


Author(s):  

The paper has been prepared on the basis of the review of water bodies management and restoration methods used in Western Caucasus Basin District. According to the monitoring data, status of many water bodies is unsatisfactory due to their pollution and clogging. Clearing of small rivers in terms of silting and overgrowing in combination with other water/protective measures is the main kind of restoration activities. Restoration works at the Nazranka River in the Republic of Ingushetia and the Elistinka River in the Republic of Kalmikia are given as the relevant examples.


2021 ◽  
Author(s):  
Leif S. Anderson ◽  
William H. Armstrong ◽  
Robert S. Anderson ◽  
Dirk Scherler

<p>Many glaciers in High Mountain Asia are experiencing the debris-cover anomaly. The Kennicott Glacier, a large Alaskan Glacier, is also thinning most rapidly under debris cover. This contradiction has been explained by melt hotspots, such as ice cliffs, streams, or ponds scattered within the debris cover or by declining ice flow in time. We collected abundant in situ measurements of debris thickness, sub-debris melt, and ice cliff backwasting, allowing for extrapolation across the debris-covered tongue. A newly developed automatic ice cliff delineation method is the first to use only optical satellite imagery. The adaptive binary threshold method accurately estimates ice cliff coverage even where ice cliffs are small and debris color varies. We also develop additional remotely-sensed datasets of ice dynamical variables, other melt hot spots, and glacier thinning.</p><p>Kennicott Glacier exhibits the highest fractional area of ice cliffs (11.7 %) documented to date. Ice cliffs contribute 26 % of total melt across the glacier tongue. Although the <em>relative</em> importance of ice cliffs to area-average melt is significant, the<em> absolute</em> area-averaged melt is dominated by debris. At Kennicott Glacier, glacier-wide melt rates are not maximized in the zone of maximum thinning. Declining ice discharge through time therefore explains the rapid thinning. Through this study, Kennicott Glacier is the first glacier in Alaska, and the largest glacier globally, where melt across its debris-covered tongue has been rigorously quantified.</p><p>We also carefully explore the relationship between debris, melt hotspots, ice dynamics, and thinning across the debris-covered tongue. In doing so we reveal a chain of linked processes that can explain the striking patterns expressed on the debris-covered tongue of Kennicott Glacier.</p>


Zootaxa ◽  
2018 ◽  
Vol 4441 (2) ◽  
pp. 201 ◽  
Author(s):  
IVAN MARIN

DNA barcoding of stygobiotic shrimps of the genus Xiphocaridinella Sadowsky, 1930 (Crustacea: Decapoda: Atyidae) collected in underground streams flowing inside two neighboring large karst caves (Otap and Abrskil сaves) revealed the presence of two distinct genetic lineages representing the first case of species co-occurrence in the Western Caucasus. The paper presents the complete morphological re-description of stygobiotic atyid shrimp Xiphocaridinella ablaskiri (Birštein, 1939) and the description of a new species using genetic and morphological analysis. Other known cases of co-occurrence of several stygobiotic shrimp species in the same cave system as well as new genetic data (COI mtDNA) on Western Caucasian species of the genus Xiphocaridinella are discussed in the paper. 


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