994 resultados para 120-748


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Photocopy. Ann Arbor, Mich. : University Microfilms, 1976.

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The discovery of the Woodleigh impact structure, first identified by R. P. lasky, bears a number of parallels with that of the Chlcxulub impact structure of K-T boundary age, underpinning complications inherent in the study of buried impact structures by geophysical techniques and drilling. Questions raised in connection with the diameter of the Woodleigh impact structure reflect uncertainties in criteria used to define original crater sizes in eroded and buried impact structures as well as limits on the geological controls at Woodleigh. The truncation of the regional Ajona - Wandagee gravity ridges by the outer aureole of the Woodleigh structure, a superposed arcuate magnetic anomaly along the eastern part of the structure, seismic-reflection data indicating a central > 37 km-diameter dome, correlation of fault patterns between Woodleigh and less-deeply eroded impact structures (Ries crater, Chesapeake Bay), and morphometric estimates all indicate a final diameter of 120 km. At Woodleigh, pre-hydrothermal shock-induced melting and diaplectic transformations are heavily masked by pervasive alteration of the shocked gneisses to montmorillonite-dominated clays, accounting for the high MgO and low K2O of cryptocrystalline components. The possible contamination of sub-crater levels of the Woodlelgh impact structure by meteoritic components, suggested by high Ni, Co, Cr, Ni/ Co and Ni/Cr ratios, requires further siderophile element analyses of vein materials. Although stratigraphic age constraints on the impact event are broad (post-Middle Devonian to pre-Early Jurassic) high-temperature (200-250 degrees C) pervasive hydrothermal activity dated by K-Ar isotopes of illite - smectite indicates an age of 359 +/- 4 Ma. To date neither Late Devonian crater fill, nor impact ejecta fallout units have been identified, although metallic meteoritic ablation spherules of a similar age have been found in the Conning Basin.

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A opressão e a resistência são um fio condutor dos Salmos de peregrinação, o grupo que vai do Salmo 120 até o 134. O distintivo situa-se nas formas variadas com que estas categorias são apresentadas. Este conjunto de salmos impressiona pela maneira simples e direita de dizer as coisas, sem deixar de ser profunda. A partir da análise, observamos que a opressão e a resistência surgem em variadas formas, deixando transparecer que não se trata de falar delas em sentido geral, pois envolvem diferentes formas e facetas que se entrecruzam, sendo manifestas por meio de relações de gênero, classe e raça/etnia. O objetivo desta tese é provar que a partir dos movimentos dos corpos, suas falas e suas memórias é possível apontar para práticas de relacionamentos sociais, econômicos, políticos ou religiosos, marcadas por relações de gênero, raça/etnia, classe, que não se vinculam aos interesses de sistemas institucionais. Mas surgem da interação entre experiências de opressão e resistência e se colocam como alternativas de vida. Cada salmo traz marcas de um contexto particular que se junta às particularidades do outro até revelar um único contexto e nessa dinâmica possibilitar o conjunto. Através das estruturas, formas literárias e dos conteúdos, aponta-se para a centralidade do corpo como sendo fator hermenêutico ativo que, com seu movimento, sua fala, suas memórias, mostra situações de opressão e busca por prazer. O estudo literário e os conteúdos são determinantes, tanto para a estrutura do conjunto, dividida em três grandes partes (Sl 120-122; 123-129 e 130-134), para a tematização do desenvolvimento do conjunto, quanto para a credibilidade da proposta histórica de opressão e resistência apresentada. Constata-se que a vida religiosa aparece integrada à vida social e política da qual constitui um aspecto se bem que existe mais de uma experiência religiosa, inter-relacionada. Estas experiências revelam que as visitas ao templo de Jerusalém não só eram para cumprir com os costumes religiosos, daquela época, mas principalmente, pelo interesse que peregrinos e peregrinas tinham no cotidiano de suas vidas, seus trabalhos, suas necessidades. Elas e eles souberam fazer a articulação entre a festa e a práxis. Assim, o conjunto de salmos torna-se ponte para o diálogo que revela outras vozes e outras maneiras de identificar opressão e resistência. Não para fugir ou acomodar-se, senão reconhecendo a opressão, superando-a na criatividade e na esperança. O estudo desenvolve-se em quatro capítulos. No primeiro, enfatiza-se que os textos estão entre teologia e literatura, especificamente em serem textos poéticos. A partir daí levanta-se o estado atual do estudo sobre este conjunto de salmos e aponta-se ao contexto histórico ao qual estão relacionados estes salmos. No segundo, realiza-se a análise das estruturas poéticas, até entenderque o conjunto de salmo está relacionado como um todo. No terceiro e quarto, pelos resultados do segundo, destacam-se os principais temas que de forma indiciária levam-nos à demonstração da hipótese.

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The exponential growth of studies on the biological response to ocean acidification over the last few decades has generated a large amount of data. To facilitate data comparison, a data compilation hosted at the data publisher PANGAEA was initiated in 2008 and is updated on a regular basis (doi:10.1594/PANGAEA.149999). By January 2015, a total of 581 data sets (over 4 000 000 data points) from 539 papers had been archived. Here we present the developments of this data compilation five years since its first description by Nisumaa et al. (2010). Most of study sites from which data archived are still in the Northern Hemisphere and the number of archived data from studies from the Southern Hemisphere and polar oceans are still relatively low. Data from 60 studies that investigated the response of a mix of organisms or natural communities were all added after 2010, indicating a welcomed shift from the study of individual organisms to communities and ecosystems. The initial imbalance of considerably more data archived on calcification and primary production than on other processes has improved. There is also a clear tendency towards more data archived from multifactorial studies after 2010. For easier and more effective access to ocean acidification data, the ocean acidification community is strongly encouraged to contribute to the data archiving effort, and help develop standard vocabularies describing the variables and define best practices for archiving ocean acidification data.

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A set of 114 samples from the sediment surface of the Atlantic, eastern Pacific and western Indian sectors of the Southern Ocean has been analyzed for 230Th and biogenic silica. Maps of opal content, Th-normalized mass flux, and Th-normalized biogenic opal flux into the sediment have been derived. Significant differences in sedimentation patterns between the regions can be detected. The mean bulk vertical fluxes integrated into the sediment in the open Southern Ocean are found in a narrow range from 2.9 g/m**2 yr (Eastern Weddell Gyre) to 15.8 g/m**2 yr (Indian sector), setting upper and lower limits to the vertically received fraction of open ocean sediments. The silica flux to sediments of the Atlantic sector of the Southern Ocean is found to be 4.2 ± 1.4 * 10**11 mol/yr, just one half of the last estimate. This adjustment represents 6% of the output term in the global marine silica budget.

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The Ice Station POLarstern (ISPOL) cruise revisited the western Weddell Sea in late 2004 and obtained a comprehensive set of conductivity-temperature-depth (CTD) data. This study describes the thermohaline structure and diapycnal mixing environment observed in 2004 and compares them with conditions observed more than a decade earlier. Hydrographic conditions on the central western Weddell Sea continental slope, off Larsen C Ice Shelf, in late winter/early spring of 2004/2005 can be described as a well-stratified environment with upper layers evidencing relict structures from intense winter near-surface vertical fluxes, an intermediate depth temperature maximum, and a cold near-bottom layer marked by patchy property distributions. A well-developed surface mixed layer, isolated from the underlying Warm Deep Water (WDW) by a pronounced pycnocline and characterized by lack of warming and by minimal sea-ice basal melting, supports the assumption that upper ocean winter conditions persisted during most of the ISPOL experiment. Much of the western Weddell Sea water column has remained essentially unchanged since 1992; however, significant differences were observed in two of the regional water masses. The first, Modified Weddell Deep Water (MWDW), comprises the permanent pycnocline and was less saline than a decade earlier, whereas Weddell Sea Bottom Water (WSBW) was horizontally patchier and colder. Near-bottom temperatures observed in 2004 were the coldest on record for the western Weddell Sea over the continental slope. Minimum temperatures were ~0.4 and ~0.3 °C colder than during 1992-1993, respectively. The 2004 near-bottom temperature/salinity characteristics revealed the presence of two different WSBW types, whereby a warm, fresh layer overlays a colder, saltier layer (both formed in the western Weddell Sea). The deeper layer may have formed locally as high salinity shelf water (HSSW) that flowed intermittently down the continental slope, which is consistent with the observed horizontal patchiness. The latter can be associated with the near-bottom variability found in Powell Basin with consequences for the deep water outflow from the Weddell Sea.

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To detect and track the impact of large-scale environmental changes in a the transition zone between the northern North Atlantic and the central Arctic Ocean, and to determine experimentally the factors controlling deep-sea biodiversity, the Alfred- Wegener-Institute for Polar and Marine Research (AWI) established the deep-sea long-term observatory HAUSGARTEN, which constitutes the first, and until now only open-ocean long-term station in a polar region. Virtually undisturbed sediment samples have been taken using a video-guided multiple corer (MUC) at 13 HAUSGARTEN stations along a bathymetric (1,000 - 4,000 m water depth) and a latitudinal transect in 2,500 m water depth as well as two stations at 230 and 1,200 m water depth within the framework of the KONGHAU project. Various biogenic sediment compounds were analyzed to estimate the input of organic matter from phytodetritus sedimentation, benthic activities (e.g. bacterial exoenzymatic activity), and the total biomass of the smallest sediment-inhabiting organisms (size range: bacteria to meiofauna).

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For the investigation of organic carbon fluxes reaching the seafloor, oxygen microprofiles were measured at 145 sites in different sub-regions of the Southern Ocean. At eleven sites, an in situ oxygen microprofiler was deployed for the measurement of oxygen profiles and the calculation of organic carbon fluxes. At four sites, both in situ and ex situ data were determined for high latitudes. Based on this dataset as well as on previous published data, a relationship was established for the estimation of fluxes derived by ex situ measured O2 profiles. The fluxes of labile organic matter range from 0.5 to 37.1 mgC m**2/day. The high values determined by in situ measurements were observed in the Polar Front region (water depth of more than 4290 m) and are comparable to organic matter fluxes observed for high-productivity, upwelling areas like off West Africa. The oxygen penetration depth, which reflects the long-term organic matter flux to the sediment, was correlated with assemblages of key diatom species. In the Scotia Sea (~3000 m water depth), oxygen penetration depths of less than 15 cm were observed, indicating high benthic organic carbon fluxes. In contrast, the oxic zone extends down to several decimeters in abyssal sediments of the Weddell Sea and the southeastern South Atlantic. The regional pattern of organic carbon fluxes derived from micro-sensor data suggest that episodic and seasonal sedimentation pulses are important for the carbon supply to the seafloor of the deep Southern Ocean.

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Carbonate sediments from the Kerguelen Plateau (ODP Leg 120) of Eocene to Pliocene age were investigated with rock magnetic, petrographic and geochemical methods to determine the carriers of remanent magnetization. Magnetic methods showed that the major magnetic minerals were titanomagnetites slightly larger than single domain particles. Submicrometre to micrometre-size grains of titanomagnetite were identified as inclusions in volcanic glass particles or as crystals in lithic clasts. Volcanic fallout ash particles formed the major fraction of the magnetic extract from each sediment sample. Three groups of volcanic ashes were identified: trachytic ashes, basaltic ashes with sideromelane and tachylite shards, and palagonitic ashes. These three groups could be equally well defined based on their magnetic hysteresis properties and alternating field demagnetization curves. The highest coercivities of all samples were found for the tachylite, due to the submicrometre-size titanomagnetite inclusions in the matrix. Trachytic ashes had intermediate magnetic properties between the single-domain-type tachylites and the palagonitic (altered) basaltic ashes with low coercivities. Samples which contained mixtures of these different volcanic ashes could be distinguished from the three types of ashes based on their magnetic characteristics. There was neither evidence of biogenic magnetofossils in the transmission electron micrographs nor did we find magnetic particles derived from continental Antarctica. The presence of dispersed volcanic fallout ashes between visible ash layers suggests continuous explosive volcanic activity on the Kerguelen Plateau in the South Indian Ocean since the early Eocene. The continuous fallout of volcanic ash from explosive volcanism on the Kerguelen Archipelago is the source of the magnetic particles and thus responsible for the magnetostratigraphy of the nannofossil oozes drilled during Leg 120.

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Rezension von: Martin Baethge / Eckart Severing / Reinhold Weiß: Handlungsstrategien für die berufliche Weiterbildung. Bielefeld: W. Bertelsmann Verlag 2013 (120 S.; ISBN 978-3-7639-1159-2)