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Paleozoic glaciation as an analog for Quaternary glacial cycles?
Kubíček, Martin ; Laurin, Jiří (advisor) ; Laibl, Lukáš (referee)
This bachelor thesis is focused on the comparison of the two main glacial periods of the Phanerozoic, the Late Paleozoic Ice Age and the Cenozoic Ice Age including Pleistocene. The main goal of the thesis is to compare the factors of glaciation and their controlling mechanisms on short and long-term scales, and the basic features of the Earth's circulation. Last but not least, the evaluation of unresolved questions and consideration of the possibility of using data from the Cenozoic, which point to a very complex behaviour of the climate system components. In both periods compared, the main climate driver appears to be the atmospheric greenhouse gas content. Another common feature is the declining trend in temperature, manifested initially by a less significant and ephemeral glaciation during the Upper Devonian, Eocene and Oligocene. The transition to the coldest phases with the lowest average temperature and the largest ice volume is characteristic. Based on CO2 content, amplitude of glacioeustatic oscillations or Milankovitch cycles, a sequence of several glaciation events in the Serpukhovian to Sakmarian interval can be considered as an analogue of the Pleistocene. The difference from the Pleistocene glaciation is presence of a large number of glaciation centres in the Gondwana area. Some...
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Runoff development in selected catchments in the Kyrgyz Range, Tian-Shan
Jedličková, Šárka ; Šobr, Miroslav (advisor) ; Janský, Bohumír (referee)
The main objective of this paper was to investigate runoff changes in the catchment Ala-Arca, Alamaedin and Kara-Balta in Kyrgyzstan, as well as change in climate conditions from available stations in the area. The runoff, precipitation, and temperature series were subjected to monthly, seasonal and annual analyses based on available data. Both absolute and relative data homogeneity were verified using statistical tests such as the Mann-Whitney-Pettit test, the SNHT test, and the WiIlcoxon's two- sample test for absolute homogeneity, and the Alexandersson's test for relative homogeneity. The Mann-Kendall test was used to determine the trend in each serie. There were inhomogeneities found in a number of runoff data. In most cases, the changes of rivers Ala-Arca and Kara-Balta were recorded in 1987. Compare to Ala-Arca and Kara-Balta, the changes of river Alamedin were recorded 3 years later, in 1990. There was a positive trend development by the rivers with the glacial-snow regime. However, there was no statistically significant trend for the entire time series. Key words: runoff change, precipitation, temperature, glacial-snow regime, snow-glacial regime, homogenization, Mann-Whitney-Pettit test, trend, Mann-Kendall test, glaciation, Kyrgyzstan, Tien- Shan
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Relative age dating of moraines in selected High Tatras valleys
Procházková, Barbora ; Křížek, Marek (advisor) ; Vočadlová, Klára (referee)
The submitted diploma thesis deals with relative dating of the youngest glacigenic sediments (moraines) in the upper parts of some selected valleys in the High Tatra Mountains. These moraines were stabilized after the last cold events of the last glaciation cycle. The Schmidt hammer (SH) test was used for the assessment of their relative age. This method is based on the assumption that there is a mutual relation between the degree of weathering of a tested surface and the duration of its exposure. Information about the degree of weathering is expressed by the Rebound (R) value. The measurements were taken on fifteen moraines in four valleys in the High Tatra Mountains (Mengusovská, Velká Studená, Malá Studená and Litvorova valley). A large statistical population of measurements obtained from moraine surfaces were used to analyse the variability of R values means in the same lithology. The moraines were divided on the base of SH measurements into two groups of different age. R value means and standard deviation for these groups (SK_1: R=53,5±1,2 a SK_2: R=58,6±1,5) are significantly statistically different. The results of the weathering indexes were used for the reconstruction of the pattern of deglaciation in selected upper parts of valleys (cirques). Key words: relative dating, the Schmidt Hammer,...
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Paleogeografická‚ paleoklimatologická a geochronologická rekonstrukce kontinentálního zalednění Česka
Česká geologická služba, Praha ; Růžička, Miloš ; Štěpančíková, Petra ; Franců, Eva ; Gába, Zdeněk ; Koubová, Magda ; Jankovská, Vlasta ; Lisá, Lenka ; Vídeňský, Aleš ; Braucher, Regis ; Hoare, Peter G. ; Hanáček, Martin ; Jarošová, Lenka ; Sikorová, Jana ; Tyráček, Jaroslav ; Janásková, Barbora ; Víšek, Josef ; Nývlt, Daniel
Ve zprávě jsou shrnuty výsledky projektu rozdělené podle jednotlivých dílčích projektů: Korelace ledovcových akumulací pomocí sedimentárně-petrologických metod, Paleogeografická rekonstrukce zalednění vybraných oblastí Česka a Geochronologické zařazení ledovcových akumulací a tvarů reliéfu Česka.
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Paleogeografická‚ paleoklimatologická a geochronologická rekonstrukce kontinentálního zalednění Česka
Česká geologická služba, Praha ; Vídeňský, Aleš ; Hanáček, Martin ; Jarošová, Lenka ; Janásková, Barbora ; Braucher, Regis ; Sikorová, Jana ; Hoare, Peter G. ; Růžička, Miloš ; Tyráček, Jaroslav ; Víšek, Josef ; Nývlt, Daniel
Během prvního pololetí roku 2006 byla digitalizována do GIS paleogeografická rekonstrukce Šluknovska, která byla zpracovaná v roce 2005. Nadále pokračovaly práce na paleogeografické rekonstrukci kontinentálního zalednění a studiu lokalit na Frýdlantsku, Jesenicku, Osoblažsku, Opavsku a v okrajové části Ostravské pánve. Detailně je studována geomorfologie severního svahu Jizerských hor v souvislosti s vlivem čela kontinentálního ledovce na jeho geomorfologii společně se studiem relativního stáří tvarů reliéfu na základě měření tvrdoměrným kladivem. Průběžně probíhalo zpracování vzorků na těžké minerály, petrologii klastů a statistiky vůdčích nordických souvků, které již byly i částěčně publikovány. Byly zpracovávány další lokality včetně odběru vzorků, které jsou postupně zpracovávány.
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