摘要:

Data are presented from hydrological observations from the englacial stream of the Bertil Glacier and from the terminal section of the glacier. Two types of englacial runoff regime during the ablation season have been identified. During the course of the first type of runoff, a rapid type, observed in the 1960s and 1970s, the volume of intraglacial discharge comprised 40% of total discharge. The second, slow type, whereby the volume of intraglacial discharge comprises only 10–20% of the total, dominated in the 1980s. Complete freezing of the central intraglacial discharge tunnel was recorded by the end of the cold period. Water entering the glacier in the spring of 1984 and 1985 produced a high head of pressure and resulted in the occurrence of geysers on the lower part of the glacier surface. It is assumed that the changed nature of intraglacial discharge is associated with the progressive freezing of the glacier and with changes in its hydrothermal regime. If climatic conditions remain the same, over the next 30–40 years compound discharge, i.e., involving both supraglacial and intraglacial runoff, will possibly give way to supraglacial runoff. This will affect the landforms in the terminal area of the glacier and exclude any possibility of it being used as winter water supply for the Soviet settlement at Pyramiden.

ISSN:0273-8457    

DOI:10.1080/10889378709377333

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

It has been established that glacial icings are widespread on Spitsbergen. Supraglacial icings occur due to meltwater emerging at the cold glacier surface and filling englacial cavities. The formation of icings results in the reorganization of glacier runoff. In some cases the ice of the icings protects the glacier surface from summer melting. The author has identified 110 proglacial icings, occurring at the snouts of glaciers or at some distance from them, due to the emergence of water from the glacier or from the subglacial talik zone in winter. Maximum icing growth occurs in the first half of the winter. Genetically they belong to the intermediate type. The properties of the icings and the volume and chemical composition of the water forming them are reviewed. The existence of proglacial icings has been recorded in the cases of both temperate and transitional two‐layered glaciers, with areas ranging from 2.9 km2to several hundred km2; they are absent in the case of small glaciers which are frozen to their beds. The two main mechanisms controlling the occurrence of two‐layered glaciers, and related to glacier morphology, namely changes in climatic conditions and changes in types of ice‐formation, are described. The resultant glaciers may be either quasi‐stable or unstable. On the other hand a glacier may experience intense freezing in its upper part, which may lead to cessation of winter discharge and the initiation of a proglacial icing.

ISSN:0273-8457    

DOI:10.1080/10889378709377334

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The author presents the results of field investigations into the flora of Mabel and Hooker islands in Franz‐Josef Land, carried out in 1979. She identified 41 species of plants on the two islands, bringing the total for the archipelago to 47. In the case of each island the topography and geology is described in some detail. The composition of the communities (in terms of phanerogams, lichens, and mosses) found in each habitat (e.g., raised beaches, talus slopes, stream courses, etc.) is then presented in detail. On the basis of her evaluation the author would include Franz‐Josef Land in a High Arctic tundra zone, rather than in an “arctic desert”; zone.

ISSN:0273-8457    

DOI:10.1080/10889378709377335

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The author describes tight, asymmetrical minor folds in well‐bedded sands, loams and clays exposed by thermal abrasion of ice‐rich sediments on the west coast of Yamal and the north coast of Yugor Peninsula. The folds are commonly underlain by massive bodies of ground ice. The author postulates that the folds are the product of a southward flow of ice within an ice‐sheet sitting on the Kara Shelf, over unconsolidated sediments which were already frozen.

ISSN:0273-8457    

DOI:10.1080/10889378709377336

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The article focuses on the hydrochemistry of the mouths of rivers debouching into Cheshskaya Gulf, especially the Pesha, but also to a lesser extent the Oma and other smaller streams. The author reports on seasonal and tidal variations in the different parts of these estuaries, in salinities, pH, oxygen regime, and the levels of silica, phosphate phosphorus, and nitrous nitrogen. The result is an extremely interesting picture of the complex chemical composition of the waters in this zone of mixing of river and sea water.

ISSN:0273-8457    

DOI:10.1080/10889378709377337

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The aim of the study is an initial assessment of the Soviet Far North with a view to siting possible stations to monitor background levels of atmospheric pollution, especially pollution by heavy metals. Climatic, geomorphological, and geochemical factors were taken into consideration. The latter are particularly important in view of the limited capacity of the landscapes of the Far North for self‐cleansing. Taking into consideration both nodal industrial developments such as Noril'sk or Bilibino and territorial production complexes, either existing or planned, such as those of the Northern Ob’ or Timan‐Pechora, the authors identify and map nine regions, scattered along the entire Soviet arctic littoral which they consider to be suitable sites for background monitoring stations.

ISSN:0273-8457    

DOI:10.1080/10889378709377338

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The article reviews the complex of interlocking problems posed by human activities which are leading to serious degradation of the natural environment of thetaygain Tomsk Oblast. These activities include clear‐cut logging, leading to soil erosion in some areas due to reduced infiltration capacity, to wind erosion of the soil in other areas, and to intensified bog formation in others. Man‐caused forest fires are a major hazard, especially when exacerbated by the natural hazard of infestations by Siberian tent‐caterpillars, which provide abundant fuel in the form of vast areas of dead trees. Other human activities such as land drainage, peat cutting, and bog formation due to obstruction of natural drainage by construction of roads and railways, all contribute further to degradation of thetaygaenvironment.

ISSN:0273-8457    

DOI:10.1080/10889378709377339

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

This evaluation of changes in the dimensions of the Severnaya Zemlya glaciers is based on an interpretation of cartographic data from the first aerial surveys made in 1931, and of observations conducted between 1952 and 1974. Comparison of the maps has revealed a general retreat of the margins of the ice domes and the disappearance of some glaciers since 1952. The summary data testify to the fact that the general shrinkage has affected glaciers of all morphological types. The glaciers of Bol'shevik Island experienced the greatest shrinkage, with the margins of some ice domes retreating 2–2.5 km (Fig. 1). The degradation of the glaciers is confirmed by the data on glacier mass balance. These have been derived from an eight‐year series of observations (1974–1981) on the Vavilov Dome and calculated from correlations of snow accumulations with mean winter air temperature at Cape Chelyuskin for the period 1933–1980. According to these calculations the glaciers of Severnaya Zemlya are annually losing 2–3 km3of ice, and up to 8–10 km2in individual years.

ISSN:0273-8457    

DOI:10.1080/10889378709377340

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The authors argue that the main cause for the initiation of thermokarst is local changes in the conditions of heat exchange between ground and atmosphere, e.g., changes in vegetation cover (natural or man‐induced), in snow depth, or in moisture conditions. Climate change is not the immediate initiator of thermokarst but simply provides the background against which these other local changes occur. This thesis is demonstrated with reference to temperature data for Cherskiy in the Kolyma Lowland, taking into consideration increases of varying magnitude in mean annual air temperature, mean summer air temperature, variations in snow depth and varying thermal resistivities of the moss and snow covers. It is further argued that even the Holocene Climatic Optimum could not have induced the development of thermokarst.

ISSN:0273-8457    

DOI:10.1080/10889378709377341

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

ISSN:0273-8457    

DOI:10.1080/10889378709377332

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor