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Holocene history of Arctic lakes
Roman, Matěj ; Nývlt, Daniel (advisor) ; Kavan, Jan (referee)
Holocene history of Arctic lakes Abstract Palaeolimnology in the Arctic has achieved a considerable progress in the last decades. The Arctic has changed markedly since the Last Glacial and glacier retreats caused formation of a great number of diverse lake types. Lakes of glacial origin, thermokarst lakes, fluvial lakes and lakes on raised beaches occur most often here. Palaeolimnological methods applied to the high latitude areas are used for the study of the history of individual lakes. Methods of correlation of sedimentary cores and basic interpretation of proxy records such as magnetic susceptibility, diatom biostratigraphy and content of carbon and sulphur were applied on sediments of Garmaksla Lake, Svalbard Archipelago. Climatic and ecological shifts including the Little Ice Age termination and recent warming were registered in proxy values. Keywords: lakes, palaeolimnology, palaeoclimatology, environmental changes, Holocene, Arctic
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Paleoclimatic proxies for the Upper Holocene in Central Europe
Heglasová, Veronika ; Treml, Václav (advisor) ; Nývlt, Daniel (referee)
This thesis summarizes findings of the Central European climate evolution during the Late Holocene and approaches to studying the paleoclimates. Indirect sources of evidence about a climatic variable, i.e. proxy data, are used to infer quantitative estimates of temperature or precipitation and can be subdivided into several categories: tree rings record both low- and high-frequency variability of climate with annual resolution; biological (and palynological) proxy data show evidence of longer-term climate changes which are deduced from changes of assemblages/taxa and their ecological preferences. Sedimentary chemistry, including stable isotopes 18 O a 13 C, maintains information on environmental conditions at the time of origin and deposition of sediment (thanks to fractionation and other processes); natural archives are complemented with documentary data which capture the fluctuations of climate up to monthly resolution and also extreme events. There is 44 quantitative paleoclimatic reconstructions in the Central Europe that employ the aforementioned proxy data, although the majority of research articles investigates only approximately the past one thousand years. The temperature and precipitation are reconstructed in the area of the Czech Republic for the past ~600 years. Decadal variability of...
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Geomorphological evidence of the Scandinavian glaciation in the Moravian Gate
Pavurová, Zuzana ; Engel, Zbyněk (advisor) ; Nývlt, Daniel (referee)
Geomorphological evidence of the Scandinavian glaciation in the Moravian Gate Abstract This thesis is aimed at area in the Moravian Gate which was covered by continental ice sheets during the Quaternary. The goal of this thesis is to analyze relief and ice-margin landforms in the Moravian Gate. Main parts of this thesis are: current views on the extent of glaciated area, definition ice-marginal landforms, methods my fieldwork, results and discussion. Maps and graphs were created as a part of this thesis. Present relief is very different from pleistocene relief. It is difficult find ice-margin landforms. I agree with extent of pleistocene ice sheet glaciations from Tyráček (2006).
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Continental glaciation of the northeastern part of the Frýdlant Spur
Lehejček, Jiří ; Nývlt, Daniel (advisor) ; Engel, Zbyněk (referee)
North-eastern part of Frýdlantský Spur is situated at the northern foothills of the Jizera Mountains. It represents an area, which was at least twice covered by North-European ice sheet during the Middle Pleistocene. At the same time, it is the region whose hills have the summits around the expected altitudinal limit of the maximum ice sheet extent. Therefore, it is a suitable area to study glacial trimline altitude. Schmidt hammer testing was applied to determine different state of rock surface weathering. Obtained R-values were taken as the most relevant data for glacial trimline determination. Nevertheless, other approaches (GIS analysis, outcrops, block fields and erratics mapping) were also incorporated. Interpretation of these approaches gave the altitudinal limit of ice sheets in the north-eastern part of the Frýdlantský Spur at 500 m a. s. l. ± 20 m.
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Response of selected rivers of the Bohemian Massif to lithological and structural conditions
Flašar, Jan ; Nývlt, Daniel (advisor) ; Kalvoda, Jan (referee)
Three groups of streams were selected in the area of the Bohemian Massif: the Berounka river with its source streams; the Vltava river with its tributaries the Malše and the Lužnice; the Labe river with its tributaries the Cidlina, the Bystřice and the Javorka. The lithological and tectonical influences to several parameters of the streams were studied. These parameters include: stream gradient, orientation of the stream and sinuosity of the stream. Data were obtained from digital elevation models, aerial photographs, topographical and geological maps. The longitudinal profiles of the streams (in the combination with geological cross-sections), the SL indexes and the gradient/sinuosity graphs were created on the basis of the obtained data. These tools were used for evaluation of the influence of lithology and the tectonics to the streams. The evolution of the streams and the stream-groups was evaluated and compared as well. A strong influence of lithology on the stream gradient was found on most of the analysed streams. The tectonic situation, on the contrary, had strong influence on the orientation of the streams, especially in the resistant rocks. Also, there were selected areas, where was a higher probability of quaternary vertical movements influencing the streams (mountainous areas of the Novohradské...
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Geomorphological evidence of the Scandinavian glaciation in the Moravian Gate
Pavurová, Zuzana ; Engel, Zbyněk (advisor) ; Nývlt, Daniel (referee)
Geomorphological evidence of the Scandinavian glaciation in the Moravian Gate Abstract This thesis is aimed at area in the Moravian Gate which was covered by continental ice sheets during the Quaternary. The goal of this thesis is to analyze results of work of Tyrá ček (2006). Main parts of this thesis are: current views on the extent of glaciated area, definition ice-marginal landforms, methods my fieldwork, results and discussion. Maps and graphs were created as a part of this thesis. Data was processed using MapInfo Professional 7.0 SCP software, ArcGIS 9 software a Microsoft Office Excel 2003.
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Palaeogeographic reconstruction of the continental glaciation in the Šluknov hilly land
Nývlt, Daniel ; Kalvoda, Jan (advisor) ; Šibrava, Vladimír (referee) ; Czudek, Tadeas (referee)
UNIVERZITA KARLOVA V PRAZE PŘÍRODOVĚDECKÁ FAKULTA Katedra fyzické geografie a geoekologie Paleogeografická rekonstrukce kontinentálního zalednění Šluknovské pahorkatiny (souhrn) Palaeogeographic reconstruction of the continental glaciation in the Šluknov hilly land (summary) DANIEL NÝVLT Praha, 2008 Předložená doktorská disertační práce vznikla během autorova studia na Katedře fyzické ge- ografie a geoekologie Přírodovědecké fakulty Univerzity Karlovy a při práci v České geolo- gické službě (do roku 2002 Českém geologickém ústavu) na projektu základního geologického mapování Šluknovského výběžku a na projektu Paleogeografická, paleoklimatologická a geo- chronologická rekonstrukce kontinentálního zalednění Česka. Autor práce: Mgr. Daniel Nývlt Česká geologická služba, pobočka Brno Leitnerova 22 658 69 Brno daniel.nyvlt@geology.cz Školitel: Prof. RNDr. Jan Kalvoda, DrSc. Konzultant: Doc. RNDr. Jiří Kovanda, CSc. Úvod a vymezení práce Během posledního půlstoletí byl nashromážděno velké množství nových dat, která přinesla základní údaje o zásahu kontinentálního ledovce do okrajových částí našeho území a následně upřesňovala znalosti o sedimentologických, geomorfologických, stratigrafických a paleogeografických aspektech zalednění těchto území (mj. Macoun et al. 1965, Šibrava 1967, Králík 1989, Macoun a Králík...
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Geologický výzkum Antarktidy
Masarykova univerzita, Přírodovědecká fakulta, Brno ; Univerzita Karlova v Praze, Přírodovědecká fakulta, Praha ; Česká geologická služba, Praha ; Holub, František V. ; Kadlec, Jaroslav ; Svojtka, Martin ; Máčka, Zdeněk ; Jeřábek, Petr ; Žák, Jiří ; Lexa, Ondrej ; Klán, Petr ; Košler, Jan ; Mlčoch, Bedřich ; Nývlt, Daniel ; Mixa, Petr
Závěrečná zpráva popisuje výsledky čtyřletého projekt, kterých bylo dosaženo v jednotlivých dílčích úkolech: 1. Studium zdrojových oblastí a glacifluviálních a morénových sedimentů na ostrově James Ross ve vztahu k paleoklimatologickému a paleogeografickému vývoji oblasti; 2. Organické průmyslové polutanty - jejich koncentrace, chování a degradace v prostředí Antarktidy; 3. Geomorfologický výzkum kamenných ledovců, periglaciálních a paraglaciálních fenoménů na ostrově James Ross; 4. Podrobné geologické mapování území projektovaného biologického monitoringu; 5. Tektono-metamorfní vývoj hornin akrečního prizmatu Trinity Peninsula Group; 6. Magmatické stavby antarktického batolitu (sev. část Graham Land) a způsob jeho vmístění; Sedimentologický a geomorfologický záznam zalednění na ostrově James Ross a jejich korelace s vývojem zalednění v průlivu Prince Gustav.
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