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181.
Klaus Schäfer 《GeoJournal》2000,52(1):45-58
The article describes a new form of transnational environmental conflict that developed in the wake of globalisation. Activist in this new type of conflict still act as proxies of groups under pressure but in contrast to transnational environmental conflicts hitherto the target of their protests is rather their own society at home than the location of the pressured group. Despite these conditions it is claimed that this type of metaphorical conflict is going to become more frequent as alliances are built along the oppostion to a dominant discourse. According to the model, conflicts of values are easier to transfer on stages abroad or across the Atlantic than conflicts of interests and motivation for activists is higher as the return is affecting their home society. Dynamic and features of this type of conflict are explained with help of discourse theory. 相似文献
182.
183.
Based on teleseismic broadband data, mainly recorded from stationsof the Incorporated Research Institute for Seismology (IRIS) and theGräfenberg (GRF) array in Germany, the focal mechanism and thefocal depth of the largest earthquakes in northeastern Siberia in thetime interval 1976–1996 were determined. For 9 events the relativeanelastic attenuation of the shear wave with respect to the compressionalwave along the travel paths could be calculated. Using the slip vectorsfrom the best constrained focal mechanisms and additional slip vectorsfrom Jemsek et al. (1986) and Parfenov et al. (1988), we obtained the North American–Eurasian pole of rotation west of the Cherskii mountainsat 67.1° N, 132.3° E.The investigation shows that the extension of the Arctic Mid-Ocean Ridgeinto the continental shelf acts as a continental graben structure.Actually, the crustal extension is concentrated on the eastern LaptevSea area and the seismicity of the western part of the Laptev Sea canbe explained by the assumption of a separate microplate. In the continentsoutheast of the Laptev Sea a series of northwest trending depressions,known as the Moma `Rift', are observed. Although in this region elevatedheat flow, recent volcanism and a low crustal thickness were found (i.e.Duchkov and Sokolova, 1985; Devyatkin, 1985), there is only a poorcorrelation between the seismicity and the rift valleys. So the Momastructures seem to be related to an aborted rift structure. 相似文献
184.
Wania Greiffo Klaus Herrmann Georg Müller Karl W. Strauss 《Contributions to Mineralogy and Petrology》1984,87(4):418-419
A sulfate-bearing Sr-Ba phosphate (Sr-gorceixite) formed by supergene alteration in rich iron ores from Minas Gerais, Brazil, has been studied by means of microprobe techniques. Analytical data and the structural formula are presented. 相似文献
185.
Friedrich Lucassen Gerhard Franz Rolf L. Romer Frank Schultz Peter Dulski Klaus Wemmer 《Lithos》2007,99(3-4):312-338
Sr–Nd–Pb isotope ratios of alkaline mafic intra-plate magmatism constrain the isotopic compositions of the lithospheric mantle along what is now the eastern foreland or back arc of the Cenozoic Central Andes (17–34°S). Most small-volume basanite volcanic rocks and alkaline intrusive rocks of Cretaceous (and rare Miocene) age were derived from a depleted lithospheric mantle source with rather uniform initial 143Nd/144Nd ( 0.5127–0.5128) and 87Sr/86Sr ( 0.7032–0.7040). The initial 206Pb/204Pb ratios are variable (18.5–19.7) at uniform 207Pb/204Pb ratios (15.60 ± 0.05). A variety of the Cretaceous depleted mantle source of the magmatic rocks shows elevated Sr isotope ratios up to 0.707 at constant high Nd isotope ratios. The variable Sr and Pb isotope ratios are probably due to radiogenic growth in a metasomatized lithospheric mantle, which represents the former sub-arc mantle beneath the early Palaeozoic active continental margin. Sr–Nd–Pb isotope signatures of a second mantle type reflected in the composition of Cretaceous (one late Palaeozoic age) intra-plate magmatic rocks (143Nd/144Nd 0.5123, 87Sr/86Sr 0.704, 206Pb/204Pb 17.5–18.5, and 207Pb/204Pb 15.45–15.50) are similar to the isotopic composition of old sub-continental lithospheric mantle of the Brazilian Shield.
Published Nd and Sr isotopic compositions of Mesozoic to Cenozoic arc-related magmatic rocks (18–40°S) represent the composition of the convective sub-arc mantle in the Central Andes and are similar to those of the Cretaceous (and rare Miocene) intra-plate magmatic rocks. The dominant convective and lithospheric mantle type beneath this old continental margin is depleted mantle, which is compositionally different from average MORB-type depleted mantle. The old sub-continental lithospheric mantle did not contribute to Mesozoic to Cenozoic arc magmatism. 相似文献
186.
Emelie Axelsson Jonas Pape Jasper Berndt Fernando Corfu Klaus Mezger Michael M. Raith 《Geostandards and Geoanalytical Research》2018,42(3):319-338
A new natural rutile reference material is presented, suitable for U‐Pb dating and Zr‐in‐rutile thermometry by microbeam methods. U‐Pb dating of rutile R632 using laser ablation ICP‐MS with both magnetic sector field and quadrupole instruments as well as isotope dilution‐thermal ionisation mass spectrometry yielded a concordia age of 496 ± 2 Ma. The high U content (> 300 μg g?1) enabled measurement of high‐precision U‐Pb ages despite its young age. The sample was found to have a Zr content of 4294 ± 196 μg g?1, which makes it an excellent complementary reference material for Zr‐in‐rutile thermometry. Individual rutile grains have homogeneous compositions of a number of other trace elements including V, Cr, Fe, Nb, Mo, Sn, Sb, Hf, Ta and W. This newly characterised material significantly expands the range of available rutile reference materials relevant for age and temperature determinations. 相似文献
187.
188.
Ralf Döscher Klaus Wyser H. E. Markus Meier Minwei Qian René Redler 《Climate Dynamics》2010,34(7-8):1157-1176
The relative importance of regional processes inside the Arctic climate system and the large scale atmospheric circulation for Arctic interannual climate variability has been estimated with the help of a regional Arctic coupled ocean-ice-atmosphere model. The study focuses on sea ice and surface climate during the 1980s and 1990s. Simulations agree reasonably well with observations. Correlations between the winter North Atlantic Oscillation index and the summer Arctic sea ice thickness and summer sea ice extent are found. Spread of sea ice extent within an ensemble of model runs can be associated with a surface pressure gradient between the Nordic Seas and the Kara Sea. Trends in the sea ice thickness field are widely significant and can formally be attributed to large scale forcing outside the Arctic model domain. Concerning predictability, results indicate that the variability generated by the external forcing is more important in most regions than the internally generated variability. However, both are in the same order of magnitude. Local areas such as the Northern Greenland coast together with Fram Straits and parts of the Greenland Sea show a strong importance of internally generated variability, which is associated with wind direction variability due to interaction with atmospheric dynamics on the Greenland ice sheet. High predictability of sea ice extent is supported by north-easterly winds from the Arctic Ocean to Scandinavia. 相似文献
189.
Daily maximum rainfall (R1D) was higher in the Jialing River basin, the Taihu Lake area and the mid-lower main stream section of the Yangtze River basin in the 1990s, and there was a good relationship between ECHAM5/MPI-OM model simulation and the observed data about extreme precipitation (R1D). Under the IPCC SRES A2, A1B, and B1 scenarios, R1Ds are all projected to be in increasing trends in the upper Yangtze River basin during 2001-2050, and R1D shows a more significant increasing tendency under the A2 scenario when compared with the A1B scenario before 2020. With respect to the middle and lower Yangtze River basin, an increasing tendency is projected before 2025, and since then the increasing tendency will become insignificant. There might be more floods to the south of the Yangtze River and more droughts to the north in the next decades. 相似文献
190.
Regional climate modelling over complex terrain: an evaluation study of COSMO-CLM hindcast model runs for the Greater Alpine Region 总被引:1,自引:0,他引:1
In this study the results of the regional climate model COSMO-CLM (CCLM) covering the Greater Alpine Region (GAR, 4°–19°W and 43°–49°N) were evaluated against observational data. The simulation was carried out as a hindcast run driven by ERA-40 reanalysis data for the period 1961–2000. The spatial resolution of the model data presented is approx. 10 km per grid point. For the evaluation purposes a variety of observational datasets were used: CRU TS 2.1, E-OBS, GPCC4 and HISTALP. Simple statistics such as mean biases, correlations, trends and annual cycles of temperature and precipitation for different sub-regions were applied to verify the model performance. Furthermore, the altitude dependence of these statistical measures has been taken into account. Compared to the CRU and E-OBS datasets CCLM shows an annual mean cold bias of ?0.6 and ?0.7 °C, respectively. Seasonal precipitation sums are generally overestimated by +8 to +23 % depending on the observational dataset with large variations in space and season. Bias and correlation show a dependency on altitude especially in the winter and summer seasons. Temperature trends in CCLM contradict the signals from observations, showing negative trends in summer and autumn which are in contrast to CRU and E-OBS. 相似文献