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Late glacial (Younger Dryas) glaciers and ice-sheet deglaciation in the Cairngorm Mountains, Scotland : glacier reconstructions and their palaeoclimatic implicationsStandell, Matthew R. January 2014 (has links)
The Cairngorm Mountains contain an outstanding assemblage of glacial landforms from both the deglaciation of the last British Irish Ice Sheet and the Younger Dryas readvance. Glaciers are recognised as sensitive indicators of past and present climate change and, thus, these landforms provide information about past climate and glacier-climate interaction that can be used to contextualise the present climate change. Previous interpretations have left doubt over the extent and style of the Younger Dryas readvance. In addition, the pattern and timing of deglaciation in the southern Cairngorms and, particularly, how local and external ice masses interacted is unclear. New geomorphological mapping from aerial images and fieldwork has been compiled in a GIS for a 600km2 area of the Cairngorm Mountains. This has allowed a complex pattern of ice-dammed lakes and local and regionally sourced ice margins to be reconstructed during the retreat of the last British Irish Ice Sheet. The mapping has been combined with new cosmogenic surface exposure ages taken from areas of hummocky moraine previously subject to differing age interpretations. The effect of moraine denudation on apparent 10Be ages has been checked by inverse modelling of the 10Be concentration vs. boulder height. The results indicate more extensive Younger Dryas glaciation, with glacier reconstructions and equilibrium-line altitudes (ELAs) comparable with the surrounding areas. Reconstruction of both valley and plateau-fed glaciers are presented, with modelling of local topoclimatic factors, such as radiation, avalanche and snow drifting, combined with precipitation gradients, explaining most of the variation within the glacier ELAs. The geomorphological evidence and palaeoclimatic inferences are important, alongside a growing number of palaeoglaciological studies, in acting as evaluation areas for current numerical models of ice-sheet growth and decay.
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Active tectonics and seismic hazard assessment of Afghanistan and slip-rate estimation of the Chaman fault based on cosmogonic 10Be dating / アフガニスタンの活構造と地震災害評価および宇宙線生成核種10Beによるチャマン断層の変位速度の見積もり / アフガニスタン ノ カツコウゾウ ト ジシン サイガイ ヒョウカ オヨビ ウチュウセン セイセイ カクシュ 10Be ニヨル チャマン ダンソウ ノ ヘンイ ソクド ノ ミツモリZakeria Shnizai 19 September 2020 (has links)
This dissertation focuses on the active tectonics of Afghanistan|slip-rate estimation of the Chaman fault and assessing seismic hazard in the Kabul basin. Afghanistan is a tectonically complex zone developed as a result of the collision between the Eurasian plate and the Indian plate to the southeast and the Arabian plate to the south. For seismic hazard mitigation, there is no large-scale active fault map in Afghanistan. I, therefore, mapped active and presumed active faults mainly based on interpretation of 1-arcsecond SRTM anaglyph images, and calculate the slip rate of the Chaman fautl based on 10Be TCN dating. / 博士(理学) / Doctor of Philosophy in Science / 同志社大学 / Doshisha University
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