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Number of results: 6
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Abstract

The current climate warming results in a quick recession of glaciers on the northern slopes and valleys of the Lindströmfjellet-Hĺbergnuten mountain ridge in Nordenskiöld Land. The equilibrium line altitude has risen from c. 500-550 m in 1936 to c.750 m in 2001 and c. 800 m in 2006. The slopes, almost completely glaciated during the Little Ice Age, and even in 1936, have mostly been abandoned by glaciers afterwards. The upper parts of the glaciers undergo a clear retreat diminishing their accumulative (firn) fields. The lower parts of the active glacial tongues have been transformed into marginal zones built of dead ice covered with morainic and glacifluvial deposits. The surfaces of the marginal zones are progressively lowered due to ablation of dead ice. The state of the described glaciers is not balanced under the current climatic conditions. Thus, the landscape transformation of the mountain ridge will most certainly continue.
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Abstract

Landscape changes of the Gåsbreen glacier and its vicinity since 1899 are described. Maps at 1:50 000 scale of changes of the glacier's elevation and extent for the periods 1938-1961, 1961-1990, 1990-2010, and 1938-2010 are analyzed in comparison with results of the authors' field work in the summer seasons 1983, 1984, 2000, 2005 and 2008. During all the 20th century, the progressive recession of the glacier revealed in a dramatic decrease in the thickness of its lower part, with a small reduction of its area and length. However, further shrinkage produced significant shortening and reduction in area which resulted in final decline of the Goësvatnet glacial dammed lake in 2002. Hence, the lowest (and very thick, up to 150-160 m) part of the former glacier tongue and dammed lake were transformed into a new terraced river valley south of the glacier and a typical marginal zone with glacial landforms north of the glacier. Since 1961, the equilibrium line altitude of the Gåsbreen glacier has risen from ca 350 to ca 500 m a.s.l. and now is located below the very steep rocky walls of the Mehesten mountain ridge, 1378 m a.s.l. Hence, the glacier is being fed by snow avalanches from these rocky walls and much more snow melts during the warmer summer seasons, stimulating a quicker recession of the lowest part of the glacier. This recession may be stopped only by significant climate cooling or increase in snow.
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Abstract

This paper reports on a morphometric analysis of land-terminating glaciers on southern and western Spitsbergen in the years 1936–2014. An attempt was made to estimate the deglaciation rate and the scale of its acceleration in the 21st century in the conditions of Arctic amplification. Satellite scenes and topographic map sheets were used for the study and were analyzed by means of remote sensing and GIS methods. The study covered 2000–2014 years and concluded that surface recession accelerated on average by a factor of 2.75 compared to the 1936–2000 period, while linear recession was 2.2 times faster. The greatest increase in the deglaciation rate can be observed in the case of glaciers faced to N and W sectors. The deglaciation process is the most advanced in the central part of the island, where small, compact mountain glaciers predominate. In recent years, a slowdown in the deglaciation processes in these glaciers was observed. The studies demonstrate that the deglaciation rate was mainly influenced by the basin relief determining the glacier geometry. The resultant fractal nature of the ice cover makes it highly vulnerable to the disintegration of complex glacial systems into smaller ones due to glacier thinning and the separation of outlets. The acceleration of the deglaciation rate in turn is modified by the climate factor, especially the impact of warming air masses from the N and W sectors where seas are becoming increasingly ice-free and, consequently, have an increasing heat capacity.
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Abstract

Being more sensitive to economic fluctuations, childbearing postponement increased during the second demographic transition and was accompanied by a moderate decline in the number of children per woman and the progressive rise of mother’s age at first birth. Under the hypothesis that recessions have a marked influence on population dynamics, the present study investigates spatial changes in mother’s age at birth in Greece with the aim to assess the differential impact of economic crisis along the urban-rural gradient. The percent composition of births by mother's age class – considered a gross indicator of fertility under a changing socioeconomic context – was studied at 4 spatial scales (the whole country, administrative regions, prefectures and metropolitan areas or specific economic districts) over an economic cycle from expansion to recession (1980–2016). While stimulating childbearing postponement observed since the early 1980s, empirical results of this study indicate that the 2007 recession was quite neutral on fertility trends in Greece, consolidating the traditional divide between urban and rural areas.
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Abstract

The economy of Slovakia experienced a turning point in the 1st half of 2008 and entered a phase of decline. The negative impacts of the global economic crisis became evident in the 2nd half of 2008 and led into a recession in the 1st quarter of 2009. The composite leading indicator was originally intended for forecasting of business cycle turning points between the decline and growth phases. The aim of this paper is to transform the qualitative information from composite leading indicator into quantitative forecast and verify whether the beginning of recession in Slovakia could have been identied in advance. The ARIMAX and error correction models are used for the composite reference series and GDP forecasts respectively. The nal result shows that the composite leading indicator is useful not only for identifying turning points, but also for the prediction of recession phase.
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Abstract

Although much has been written about a cosmic impact event in the Western Alps of the Mt. Viso area, the event closely tied with the Younger Dryas Boundary (YDB) of 12.8 ka and onset of the Younger Dryas (YD), the affected land surface is considered to contain a similar black mat suite of sediment found on three continents. While work elsewhere has focused on recovered sediment from lake and ice cores, buried lacustrine/alluvial records, and surface glacial and paraglacial records, no one has traced a mountain morphosequence of deposits with the objective of investigating initial weathering/ soil morphogenesis that occurred in ice recessional deposits up to the YDB when the surface was subjected to intense heat, presumably, as hypothesized by Mahaney et al. (2016a) from a cosmic airburst. With the land surface rapidly free of ice following glacial retreat during the Břlling-Allerřd interstadial, weathering processes ~13.5 to 12.8 ka led to weathering and soil morphogenesis in a slow progression as the land surface became free of ice. To determine the exposed land character in the mid- to late-Allerřd, it is possible to utilize an inverted stratigraphic soil morphogenesis working backward in time, from known post-Little Ice Age (LIA) (i.e. time-zero) through LIA (~0.45 to ~0.10 ka), to at least the middle Neoglacial (~2 ka), to answer several questions. What were the likely soil profile states in existence at the end of the Allerřd just prior to the cosmic impact/airburst (YDB)? Assuming these immature weathered regolith sections of the Late Allerřd approximated the <1 ka old profiles seen today, and assuming the land surface was subjected to a hypothesized instant temperature burst from ambient to ~2200oC at ~12.8 ka, what would be the expected effect on the resident sediment? To test the mid-LG (YDB) to YD relationship we analyzed the paleosols in both suites of deposits – mid-LG to YD – to test that the airburst grains are restricted to Late Allerřd paleosols and using relative-age-determination criteria, that the overlapping YD to mid-LG moraines are closely related in time. These are some of the questions about the black mat that we seek to answer with reference to sites in the upper Guil and Po rivers of the Mt. Viso area.
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