ISSN:0273-8457    

DOI:10.1080/10889379209377486

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0273-8457    

DOI:10.1080/10889379209377487

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The ecological‐geographical mapping of the high‐latitude areas of Russia that has been carrìed out was based on ranked evaluations of the physical degradation of the environment under the impact of man's activities. The ranking scale was constructed using a matrix that took into account various types of anthropogenic stresses. This approach allowed us to present with an adequate degree of contrast three major blocks: the severely degraded land areas of North European Russia; the lightly developed areas of the north of East Siberia and the Far East; and an intermediate zone in the north of West Siberia where development has occurred with nodal and linear concentrations.

ISSN:0273-8457    

DOI:10.1080/10889379209377488

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The study concentrates on the apparent contradiction in the occurrence of tundra peat deposits, namely that they are so widespread yet that much of the peat appears to be relict, on the basis of observations in the Amguema valley and in the Anadyr' Lowland in Chukotka. Results reveal that over wide areas the peat accumulations are experiencing denudation, i.e., that erosion of the peat is occurring faster than accumulation of organic material. This appears to be associated with greater surface runoff than during the peak period of peat accumulation. A related phenomenon, associated with the greater availability of moisture, is the recent invasion of many areas of peat formation bySphagnumparticularly in the Anadyr' Lowland. The study concludes with detailed analyses of the peculiarities of peat formation in polygonal tundra bogs and in string bogs.

ISSN:0273-8457    

DOI:10.1080/10889379209377489

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Simple field techniques were used to study the evolution of the glaciers in the Kongsfjorden area during the late Holocene. It was demonstrated that the Kongsbreen experienced a Neoglacial advance prior to the Little Ice Age. Moreover, despite the present tendency to retreat, the flow velocity in the ice near the snout of the Kongsbreen has been constant for about 20 years (as determined by reference to studies by Pillewizer and Voigt). Finally, a good correlation was obtained between the mass balance of small cirque glaciers in the area and two climatic parameters, summer temperatures and spring precipitation(r =0.84).

ISSN:0273-8457    

DOI:10.1080/10889379209377490

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The paper presents the Cenozoic history of the topography of the South Kara shelf. It represents a peripheral part of the West Siberian plate submerged beneath the Kara Sea. The principal morphostructures are remnants of the South Kara arch, the Baidaratsk foredeep, and the East Novaya Zemlya trench. Structural‐denudational levels are identified as having been formed during regressive episodes in the Late Oligocene, Late Miocene, the Late Pliocene/Pleistocene, the late Middle Pleistocene, and at the Pleistocene/Holocene boundary. Submarine erosional‐depositional levels were formed during transgressive epochs during the Early/Middle Miocene, Pliocene, Early/Middle Pleistocene, Late Pleistocene, and Holocene.

ISSN:0273-8457    

DOI:10.1080/10889379209377491

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The data presented are the results of Soviet‐Polish field studies made on Hansbreen in 1989. Data from geodetic surveys show that between 1936 and 1989 the glacier retreated approximately 900 m and thinned in its lower part by an average of 50 m. Over this same period its volume shrank by 1.25 km3of ice, i.e., by 0.46 m/ yr of water equivalent. The annual mass balance of the glacier in 1988–1989 was ‐540 g/cm2; of this ‐350 g/cm2, or 65% of the total, was lost by iceberg calving. Thus in 1988–1989 the glacier lost 30.55 million m3of water, 20 million m3of which was by iceberg calving. In the year of observations the equilibrium line lay at a height of 325 m and the accumulation zone accounted for 0.53 of the total area. According to data from surface radio echo soundings 75% of the area of the glacier bed lies below sea level, at depths of up to 102 m. Three overdeepened basins were detected in the glacier bed; the intervening bars might act as stabilization levels in the course of retreat. The heterogeneous structure of the glacier, the presence of internal reflecting boundaries, and considerable differences in the velocities of electromagnetic waves between them, testify to the existence of zones of “cold”; and “warm”; ice in the complex hydrological regime of Hansbreen.

ISSN:0273-8457    

DOI:10.1080/10889379209377492

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The authors draw on recent Soviet and foreign geophysical papers to draw a general map of crustal thickness for the entire Arctic region.

ISSN:0273-8457    

DOI:10.1080/10889379209377493

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0273-8457    

DOI:10.1080/10889379209377485

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor