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To better prioritise adaptation strategies to a changing climate that are currently being developed, there is a need for quantitative regional level assessments that are systematic and comparable across multiple weather hazards. This study presents an indicator-based impact assessment framework at NUTS-2 level for the European Union that quantifies potential regional changes in weather-related hazards: heat stress in relation to human health, river flood risk, and forest fire risk. This is done by comparing the current (baseline) situation with two future time periods, 2011–2040 and 2041–2070. The indicator values for the baseline period are validated against observed impact data. For each hazard, the method integrates outcomes of a set of coherent high-resolution regional climate models from the ENSEMBLES project based on the SRES A1B emission scenario, with current and projected non-climatic drivers of risk, such as land use and socio-economic change. An index of regional adaptive capacity has been developed and compared with overall hazard impact in order to identify the potentially most vulnerable regions in Europe. The results show strongest increases in impacts for heat stress, followed by forest fire risk, while for flood risk the sign and magnitude of change vary across regions. A major difference with previous studies is that heat stress risk could increase most in central Europe, which is due to the ageing population there. An overall assessment combining the three hazards shows a clear trend towards increasing impact from climaterelated natural hazards for most parts of Europe, but hotspot regions are found in eastern and southern Europe due to their low adaptive capacities. This spatially explicit assessment can serve as a basis for discussing climate adaptation mainstreaming, and priorities for regional development in the EU.  相似文献   
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Ancient carbonate buildups may contain extraordinarily large amounts of early diagenetic precipitates. In some, host rock lamination may be traced into inclusion bands within the 'cement' crystals, suggesting that the crystals are replacive. By analogy with a Pleistocene speleothem from the Sorrento Peninsula, however, these relationships can be explained differently. In the speleothem, large, repeatedly split and dendritic calcite crystals occur within a laminated carbonate. Lamination consists of sub-mm alternations of micrite and microspar. Micritic laminae pass laterally into inclusion-rich growth bands in the dendritic calcite crystals, and have replaced an aragonitic cement, whereas the microspar laminae were primary calcite cements. Three types of inclusion-rich bands occur in the dendrite crystals: (1) with aragonite relicts, (2) 'ribbon calcite' and (3) with oriented micropores. When aragonite precipitated, the calcite dendrite branches were unable to keep growing as single crystals and split into crystallites (separated by micropores, some forming ribbon calcite), whereas during episodes of calcite lamina precipitation, the larger crystals were regenerated by crystallite coalescence. Calcite crystals are primary: they did not replace a micritic precursor. By analogy with the Italian speleothem, some ancient reefal sparry carbonates may not be replacements of earlier laminated sediments, but may have grown concurrently with them. It is also probable that some ancient laminated sediments were instead sea-floor precipitates, and that stromatolites containing cross-cutting crystal fabrics, and the alternating micrite-microspar laminae typical of Archaeolithoporella , could be largely abiotic crystal growths.  相似文献   
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Major- and trace-element systematics of the magmas erupted during the recent activity of Vesuvius (1631–1944) show that composition ranges are narrow and identical in each activity cycle except for the 1631 eruption which emitted also more differentiated products. These rocks are the most basic magmas erupted in Vesuvius. The high K and incompatible-element contents of these products are characteristic of the whole Roman-Campanian Province.Lavas and tephra of the 1906 and 1944 eruptions are highly porphyric. Geochemical modelling shows that these products are mechanical mixing of a slightly differentiated melt and various proportions of phenocrysts. Except ratios of highly incompatible trace elements (Th/La, Th/Ta, Th/Ba), no chemical characteristics of primary and differentiated melts can be simply inferred from bulk erupted products. An inverse method for calculating melt and mineral compositions is presented. Calculated weigth fractions are consistent with measured modal compositions. A model of crystal differential accumulation controlled by relative phase densities and eruption rates is proposed.  相似文献   
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NOAA 8210 has been a region showing a remarkable level of activity well before solar maximum. Dominated by a large, rapidly rotating spot, it produced several intense flares during its disk passage at the end of April–beginning of May 1998. We examine the development of AR 8210 in H and white light (WL) and study the evolution of its complex magnetic topology. While the other principal flares are briefly reviewed, the great X1.1/3B flare of 2 May, which was observed at Kanzelhöhe Solar Observatory during a SOHO/UVCS ground support campaign, is studied in detail. This event has been documented in full-disk H and Na-D intensitygrams, Dopplergrams, and magnetograms, with a time cadence of one minute each. The flare was associated with a CME and produced significant geomagnetic effects. Furthermore, we point out the perspectives for our planned Flare Monitoring and Alerting System, since the two new instruments (Magneto-Optical Filter and Digital H camera), which made their first operational run with the campaign, are crucial components for this program.  相似文献   
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A theoretical study of some thermoelastic and structural properties of forsterite, at non-ambient conditions, is presented in this work. A site-dependent potential (NP) has been developed, and successfully used to carry out theoretical investigations on the lattice parameters, specific heat and tensorial elastic properties of forsterite, at P and T conditions representative of the actual thermobaric environment of the upper mantle of the Earth. Calculations have been performed in the framework of lattice dynamics and of quasi-harmonic approximation. The results, from high temperature or high pressure simulations, have been compared with experimental data. Calculations at high pressure and high temperature have provided unprecedented data, which are not easy to achieve experimentally. Received: October 10 1997 / Revised, accepted: January 26 1998  相似文献   
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