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印尼8.7级巨震后云南地震活动的频度变化 总被引:1,自引:0,他引:1
0引言
2004年12月26日在印尼苏门答腊西北近海发生了8.7级巨震,3月29日在距8.7级地震破裂区东南160km又发生了一次8.5级地震。8.7级地震发生后,余震向震中以北扩展达千米以上。如此剧烈的能量释放,对我国的地震活动有何影响是令人关注的,但清晰解答这个问题并非易事,主要原因是,一个地区的大地震发生后如何影响另一个地区地震活动的机制目前我们并不清楚。这个机制可能很复杂,涉及到应力在地壳和地幔内的传播、积累,以及与地质构造等的关系。因此,仅从时间尺度上判定一个地区的大地震对另一个地区地震活动是否有影响在认识上就存在分歧。例如,是一个地区的大地震发生后的波动在传播到另一个地区时直接触发的地震活动才被看作是影响?还是由于一个地区的大地震发生后的应力释放和调整影响到另一个地区的地震活动才被看作是影响?显然,这两方面的影响在时间尺度上存在差异。8.7级地震发生后不到20分钟,在我国云南的宾川发生了4.6级地震,其发震时间也是8.7级地震的面波到达该地区的时间(李刚等,2005); 相似文献
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When selecting produced water treatment technologies, one should focus on reducing the major contributors to the total environmental impact. These are dispersed oil and semi-soluble hydrocarbons, alkylated phenols, and added chemicals. Experiments with produced water have been performed offshore on the Statoil operated platforms Gullfaks C and Statfjord B. These experiments were designed to find how much of the environmentally relevant compounds were dissolved in the water phase and not associated to the dispersed oil in the produced water. Results show that the distribution between the dispersed oil and the water phase varies highly for the different components groups. For example the concentration of PAHs and the C6-C9 alkylated phenols is strongly correlated to the content of dispersed oil. Therefore, the technologies enhancing the removal of dispersed oil have a higher potential for reducing the environmental impact of the produced water than previously considered. 相似文献
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1999年辽宁省岫岩5.4级地震的临震预报及其地震活动研究 总被引:3,自引:0,他引:3
1999年11月29日12日10分(北京时间),中国辽宁省岫岩地区发生一次5.4级地震。这次地震前,在震区记录到丰富的中小地震活动,组成了完整的地震系列。该系列具有小震频度随时间增多,震级上升,b值较低,地震位置集中和地震P波被动一致,将其判断为震前系列,并抓住了前震活动从密集突然变为相对平静这一大震即将发生的特征,作出了临震预报,于11月28日晚入震意见通报给辽宁省地震局有关部门。这次地震的预报 相似文献
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Per Johan Brandvik Øistein JohansenFrode Leirvik Umer FarooqPer S. Daling 《Marine pollution bulletin》2013
Size distribution of oil droplets formed in deep water oil and gas blowouts have strong impact on the fate of the oil in the environment. However, very limited data on droplet distributions from subsurface releases exist. The objective of this study has been to establish a laboratory facility to study droplet size versus release conditions (rates and nozzle diameters), oil properties and injection of dispersants (injection techniques and dispersant types). This paper presents this facility (6 m high, 3 m wide, containing 40 m3 of sea water) and introductory data. Injection of dispersant lowers the interfacial tension between oil and water and cause a significant reduction in droplet size. Most of this data show a good fit to existing Weber scaling equations. Some interesting deviations due to dispersant treatment are further analyzed and used to develop modified algorithms for predicting droplet sizes in a second paper (Johansen et al., 2013). 相似文献
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Karbi Anglong and North Cachar Hills districts of Assam are endowed with rich and diverse vegetation resources. Increased human pressure due to shifting cultivation and raw material extraction for industrial purposes are heavily altering the forested landscape. The present study deals with mapping of forest types in the two districts using LANDSAT-MSS digital data. The maps thus generated provide spatial distribution of bioclimatic vegetation types. Supervised maximum likelihood classification has been performed using training sets collected during field work. The spectral behaviour of vegetation types have been studied for optimising classification scheme. The classification accuracy of classes mapped has been calculated. 相似文献
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Fredrik Høgaas Louise Hansen Ivar Berthling Martin Klug Oddvar Longva Helle Daling Nannestad Lars Olsen Anders Romundset 《Boreas: An International Journal of Quaternary Research》2023,52(3):295-313
This study discusses the timing and maximum flood level of the Nedre Glomsjø outburst flood, Norway, based on sediment records retrieved from 15 bog and lake basins located close to the purported maximum flooded level. The sediment records in 12 of the basins consist of a distinct light-coloured silty bed that is correlated to the outburst-flood-deposited ‘Romerike Silt Bed’ identified elsewhere in the region. The silt bed is recorded in basins up to a certain elevation and is absent above this level. The new maximum flood level inferred from the basin sediment records exceeds the established landform-induced palaeostage indicators by 5–10 m. The data indicate a higher maximum flood level and larger inundation area than previously suggested and highlight the importance of acquiring a wide range of geological data when reconstructing palaeofloods. Radiocarbon dates of terrestrial macrofossils found stratigraphically above and below the Romerike Silt Bed suggest that the glacial lake Nedre Glomsjø outburst flood occurred between 10.5 and 10.3 cal. ka BP. The new and well-constrained timing of the outburst flood is beneficial for reconstructing regional deglaciation and provides a precise age for the Romerike Silt Bed chronostratigraphical marker, which is of value for studies in SE Norway and adjacent regions. 相似文献
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