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1.
选用了兰州地震台大震速报仪器 DK- 1中长周期记录仪记录到的 1990年 1月~ 1999年 3月的大震速报地震共 5 44个 ,与中国地震局分析预报中心编纂的《中国地震速报台网观测报告》给出的震级比较 ,对兰州地震台 DK- 1地震仪测定的面波震级 (Ms)进行了对比和分析研究。结果认为兰州地震台大震速报 DK- 1地震仪测定的面波震级(Ms)偏差与震中距离、震中区域及地震大小有关。给出了不同震中距离、不同震级范围及不同地区发生地震的面波震级台基校正值 ,供在今后的速报工作中参考使用 ,将有助于提高兰州台大震速报的震级测定精度。  相似文献   

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利用云南区域数字地震台网46个地震台的记录资料,将2002-2008年间云南区域数字地震台网速报的、震中位于云南省界外300 km以内邻省(国)的中强震速报定位参数,与中国地震台网中心正式速报结果(M≥5.0)(中国地震台网大震速报目录,2002-2007年)及云南地震台网正式速报结果作比较(M<5.0),总结速报分析...  相似文献   

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论述了适用于遥测地震台网大震速报的一套计算机处理系统,系统设计以《全国遥测台网观测技术规范》和《近震分析》理论为依据,实现了数据输入,震相选择,数据处理,地震定位,震级计算,结果输出及贮存等多项功能,达到了快速确定地震三要素,提高速报速度和精度之目的,是一个较完善的,实用的速报系统。  相似文献   

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姚安地震序列与永胜地震序列的高精度定位   总被引:11,自引:3,他引:11  
2000年1月15日云南省姚安地区发生了Ms 6.5地震,2001年10月27日云南永胜地区发生了Ms 6.0地震,两者均位于滇中块体,震中相距较近,构造相似,且各自都有丰富的余震活动。为深入研究姚安、永胜两地震的主震及余震序列的分布与破裂特征,根据云南省地震局布设的流动数字台网记录到的余震序列的震相资料,分别联合采用盖格定位法和双差定位法得出了这两个余震序列的时空分布。在此基础上,联合昆明区域台网记录的两个主震和较大余震的震相资料,利用双差定位法重新校正了姚安和永胜两次主震的震源参数。根据地震序列的时空分布,结合两个地震区的地质构造、所属块体的受力状态等特征,对比分析了两个地震余震序列沿断层面破裂的特点。  相似文献   

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北京台网震相分析与大震速报   总被引:2,自引:0,他引:2  
阐述了北京台网近远震和特殊震例的震相分析以及如何迅速准确地对大震进行速报。  相似文献   

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选取2008年以来内蒙古自治区、内蒙古测震台网速报范围内的所有地震事件,分别采用单纯型、LocSAT、Hyposat、HYP2000地震定位方法进行重新定位。以定位结果中的发震时刻、震中位置、震源深度、震级残差为主要分析对比指标,与国家台网中心发布的正式速报结果进行对比,发现单纯型定位方法为区内速报地震的优选方法。  相似文献   

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内蒙古数字化记录近震震相特征   总被引:1,自引:0,他引:1  
对内蒙古测震台网2008年以来速报的346次地震(包括天然地震与爆破、塌陷)进行统计,以典型震例,分区域、分类别总结震相特征。在此基础上,讨论利用典型震例与波形互相关性在未来地震定位与震相精确识别方面应用的可能性,及利用非常规震相(sPn震相)准确测定震源深度的应用前景。通过以上分析,以期进一步提高内蒙古地震速报和编目工作质量。  相似文献   

8.
对内蒙古测震台网2008年以来速报的346次地震(包括天然地震与爆破、塌陷)进行统计,以典型震例,分区域、分类别总结震相特征。在此基础上,讨论利用典型震例与波形互相关性在未来地震定位与震相精确识别方面应用的可能性,及利用非常规震相(sPn震相)准确测定震源深度的应用前景。通过以上分析,以期进一步提高内蒙古地震速报和编目工作质量。  相似文献   

9.
对2009年2月至2011年8月新疆及边境界外300 km以内Ms3.0以上523个天然地震重新分析,研究新疆数字化近震记录,总结震相规律,地震实例说明:不同距离、不同类型的天然地震记录特征,对提高新疆数字台网中心的地震速报及地震目录编辑质量具有借鉴意义.  相似文献   

10.
昆明区域数字遥测台网从开始建设至今,一系列台网软件的相继研制并完善,特别是解决了数字地震仪系统传递函数的计算、定位精度、地震震级、大地震信息发布等相关的一系列技术难题,通过对技术系统的改进和完善,地震监测和大震速报相对于以往的模拟台网取得了长足的进步。从1999年11月25日的澄江5.2级地震,到2003年11月15日的鲁甸5.1级地震共18次5级以上地震,昆明台网都以快速准确的地震参数向中国地震局和云南省地震局速报,为抗震救灾争取了宝贵的时间,得到了云南省和云南省地震局的一致好评,在云南的防震减灾事业中做出了相应的贡献。  相似文献   

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正Director:Shangfu Kuang,China Vice-directors:Chunhong Hu,China Duihu Ning,China Guangquan Liu,China The International Research and Training Center on Erosion and Sedimentation(IRTCES)was jointly set up by the Government of China and UNESCO on July 21,1984.It aims at the promotion of international exchange of knowledge and cooperation in the studies of erosion and  相似文献   

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正SCIENCE CHINA Earth Sciences,an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China,and published by Science China Press and Springer,is committed to publishing high-quality,original results in both basic and applied research.  相似文献   

17.
Feedback mechanisms, which operate upstream through drawdown and backwater effects and downstream through sediment discharge are responsible for channel evolution. By combining these mechanisms with channel processes it euables a dynamic process-response model to be developed to simulate the initial evolution of straight gravel-bed channels. When erosion commences on a land surface, sediment entrained in the headwater reach by hydraulic action is selectively transported, deposited and reworked. This produces a damped oscillation between degradation and aggradation as the channel and valley respond to spatial and temporal variations in sediment calibre and hydraulic conditions. The initial cut and fill phases are responsible for valley incision and floodplain development while secondary and subsequent activity can produce river terraces. Eventually sediment entrainment in the headwaters declines as slopes are reduced. Subsequent channel evolution is relatively insignificant because it is dependent on local weathering activity producing material that can be transported on declining slopes. Therefore landforms produced during the initial phase of development, when local weathering was non-limiting, dominate the landscape.  相似文献   

18.
Based on relocating the Jiujiang-Ruichang earthquake sequence which occurred on November 26, 2005 in Jiangxi Province with the double-difference (DD) algorithm and master event technique, the paper discusses the focal mechanism of the main shock (MsS.7) and the probable seismo-tectonics. The precise relocation results indicate that the average horizontal error is 0.31kin in a EW direction and 0.40kin in a NS direction, and the average depth error is 0.48kin. The focal depths vary from 8kin to 14kin, with the predominant distribution at 10kin - 12kin. The epicenter of the main shock is relocated to be 29.69^oN, 115.74^oE and the focal depth is about 10.Skin. Combining the predominant distribution of the earthquake sequence, the focal mechanism of the main shock and the tectonic conditions of N-E- and NW-strike faults growth in the seismic region, we infer that the main shock of the earthquake sequence was caused by a NW striking buried fault in the Rnichang basin. The nature of seismic faults needs to be further explored.  相似文献   

19.
Abstract

The western reservoirs represent the principal groundwater system in Morocco. Demographic, industrial and agricultural developments during the last decade have markedly altered groundwater quality. The Mamora coastal aquifer system is among the Atlantic systems which are most heavily threatened by pollution. Agricultural and industrial activities, and rapid urban growth contribute to the pollution of the groundwater. Contamination transport is facilitated by a high permeability of the aquifer formations. In order to assess the actual groundwater quality of the Mamora aquifer and to understand the influence of the factors generating the pollution, an extensive multidisciplinary research programme is in progress, with hydrochemistry and microbiology playing essential roles. The present paper concerns the spatial distribution of physico-chemical parameters in the groundwater, subjected to domestic, industrial and agricultural pollution. Fifty-seven samples were analysed for several parameters (Ca2+, Mg2+, Na+, K+, Cl?, SO4 2?, HCO3 ?, NO3 ?, pH, electrical conductivity and temperature). The microbiological analysis of 143 samples reveals the presence of four kinds of indicator bacteria in the groundwater resources: faecal Streptococci, faecal coliform, Escherichia coli and Clostridium. The physico-chemical results and bacteriological monitoring show that the nitrate and bacteria concentrations exceed the maximum admissible levels, notably around pumping stations in the sectors of Sidi Taibi, Sidi Ahmed Taleb and Aïn Sbaâ. Contamination is generated by uncontrolled anthropogenic activities and accentuated by the high intrinsic vulnerability of the aquifer system. Several parameters appeared to exceed admissibility standards. Measures are recommended to prevent groundwater pollution in the region.  相似文献   

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正SCIENCE CHINA Earth Sciences,an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China,and published by Science China Press and Springer,is committed to publishing high-quality,original results in both basic and applied research.  相似文献   

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