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171.
The fault F5 is considered as the most active fault in the Tanlu fault zone(Yi-Shu fault zone), which is located from Weifang of Shandong Province to Jiashan of Anhui Province, with a length of 360km. It has always been a focus of concern to many geoscientists because of its complexity and importance. But, for a long period of time, there exists biggish indetermination in the accurate position and active ages of the fault F5 in Suqian section of Tanlu fault zone. Seismic reflection exploration is the main technique in present urban active faults detecting. In order to investigate the spatial distribution, characteristics and activities of the fault F5 in covered terrains, we carried out a systematic survey to the fault with shallow seismic prospecting method and obtained the accurate position and development characteristics of the fault. The results show that the fault F5 continues to develop toward south rather than ending at the Huancheng South Road of Suqian City. F5 is mainly composed of two main faults, which dip in opposite directions and almost vertically. Near the Sankeshu town, F5 is composed of three faults with right-stepping, forming a small pull-apart basin with length of 6km, width of 2.5km, controlling the deposition of Neogene and Quaternary strata. By combining the results of composite drilling section and trenching, we make a conclusion that the western branch of fault F5 is a Holocene active fault, and the eastern branch is a Pleistocene active fault. Our general view is that fault F5 is a Holocene active fault.  相似文献   
172.
地震电磁成因假说   总被引:2,自引:1,他引:1  
张宝盈 《高原地震》2005,17(2):1-21
为了找到符合或接近自然真实的地震成因,结合地震学、电磁学、等离子体物理、空间物理等学科的一些研究成果,提出一个新的地震成因机制,对各种地震现象做出了合理解释。有证据表明,地震可能是一种电磁和化学效应。它可能是由于受太阳活动调制的电离层、磁层等离子体电场与地表之间的电磁感应以及地壳内部的电过程,导致大量荷电粒子(等离子体)因趋肤效应在地壳表层的某些区域积聚,积聚在数万至数百万平方千米地表中的巨量等离子体在诸如太阳活动的影响下达到了等离子体复合的条件时,就会发生猛烈的集体复合。由于等离子体复合是一种放能过程,因而会释放出巨大能量。同时由于存在辐射复合过程而产生地光,等离子体复合的爆炸效应导致类似打雷、放炮的地声,并释放出沿球面均匀地向四周传播的地震波,由此形成的强磁场中的洛伦兹力使地面产生强烈旋扭而使地面出现左旋或右旋的地裂缝。与地震密切相关的一些自然现象如干旱、台风、暴雨、热异常以及地震中的喷水冒沙、地震云等现象,都可以由此得到统一的解释。  相似文献   
173.
F子夜均值逐日差空间异常变化与地震的关系研究   总被引:2,自引:0,他引:2  
利用2010年1月1日至2014年4月30日我国地磁台网100多个台站的地磁总强度F子夜均值数据,逐一分析了F子夜均值逐日差的空间变化趋势。结果表明,在此期间有18次小区域的异常变化,其中16次异常与其后几天到半年时间内该区域发生的地震有很好的对应关系,另外两次新近的异常有待后续进一步验证。我国西北部地区地磁台站稀疏,布局不合理,限制了对新疆、青海、西藏等地震多发区震磁关系的研究,建议这些地区进一步加密台站建设,优化布局。  相似文献   
174.
应用内蒙古、黑龙江、吉林、辽宁地磁台站总场F北京时21点绝对观测值,研究了其空间相关性在前郭5.8级震群前的变化,结果显示,在地震前地磁总场F空间相关性会出现下降异常变化,根据异常变化,提出判定异常区域方法,提出的判定方法与实际发震区域一致。  相似文献   
175.
福建省天湖山煤矿区F31推覆断层及找煤方向探讨   总被引:1,自引:0,他引:1  
福建省天湖山煤矿区处于闽西南坳陷东条带,推覆构造极其发育,以F31和F1两条推覆断层表现最为突出。据矿区开采资料证实,F31断层下盘童子岩组为—总体向西倾斜向南倾伏、轴向NNE的紧密线状褶皱,断层较稀少;上盘构造复杂,断层发育,由F31所派生的低序次断层往往为逆掩或逆冲断层,与主断层面组成“入”字型构造,造成童子岩组地层多次重复,同时派生了更低序次的断层组成羽毛状构造。通过对F31推覆断层特征以及应力场分析研究,认为其演进过程为:童子岩期前后的成岩沉积—印支期侧向挤压形成褶皱—印支运动及其后由于侧向挤压形成软弱滑动面及断裂—燕山早期侧向挤压造成低角度推覆断层。根据该矿区构造研究成果,提出了矿区外围及深部的5个找煤方向。  相似文献   
176.
A Corythosaurus skull (UALVP 13) was collected in 1920 from what is now Dinosaur Provincial Park in southern Alberta, Canada and was designated the holotype of Corythosaurus excavatus, a new hadrosaur species by Gilmore (1923). In 1992, a previously uncovered, weathered, headless skeleton was found. This was collected in 2012 by the University of Alberta as there was potential it could belong to the holotype skull. In addition, an isolated hadrosaur dentary had been found in 1992 close to the articulated postcranial skeleton and may be one of the missing jaws of Corythosaurus excavatus. The hypothesis that it may be the skeleton of the holotype of Corythosaurus excavatus is tested using anatomical information and statistical analyses. Statistical comparisons suggest it is possible that the skull and dentary belong to the same specimen. Furthermore, bivariate plots and percentage prediction errors also indicate that the postcranial material could belong to the UALVP 13 skull. Because many large vertebrate fossil specimens (even types) are not always collected in their entirety, this method may be used as a line of evidence to determine whether independently collected specimens potentially belong to the same individual. The problems described herein highlight the need to collect specimens in their entirety, and for good field documentation, including the spatial and stratigraphic context of all finds.  相似文献   
177.
Accurate species identification and biogeographic characterisation are fundamental for appropriate management of expanding cephalopod fisheries. This study addresses this topic within the common cuttlefish Sepia officinalis species complex (S. officinalis, S. hierredda and S. vermiculata), with an emphasis on occurrence in African waters. Tissue samples from the currently presumed distributions of S. vermiculata and S. hierredda (from South Africa and Ghana/Angola, respectively) were sequenced for the cytochrome c oxidase subunit I (COI) and the cytochrome b (cytb) genes of the mitochondrial genome and then compared to existing S. officinalis sequences. Three highly divergent and reciprocally monophyletic clades, corresponding to S. officinalis, S. hierredda and S. vermiculata, were resolved, representing the first molecular confirmation of the distinct species status of S. hierredda and S. vermiculata. The sequences also revealed that, contrary to expectations based on presently published information, all samples from southern Angola were S. vermiculata. These results indicate that the range of S. vermiculata extends beyond the currently described northern limit and that S. hierredda and S. vermiculata may be indiscriminately harvested in Angolan waters. Finer-scale patterns within S. vermiculata phylogeography also indicate that the Benguela Current System and/or other environmental factors serve to isolate northern and southern stocks.  相似文献   
178.
本文计算并讨论了当13C以渐进注入方式进入氦燃烧壳层时,19F在小质量AGB星热脉冲中的核合成问题.采用小质量AGB星热脉冲的氢氦混合燃烧模型,中子源为13C(a,n)16O,质子则是脉冲开始时从氢燃烧壳层卷入的.对丰度的数值计算结果表明,在小质量AGB星的热脉冲中,19F是能够有效合成的,有效合成的温度T的范围为1.8≤D<2.8(T8=T/108K).采用小质量AGB星的挖掘模型,计算了AGB星大气中氟、氧等元素丰度的变化,较好地拟会了观测结果.对中子源的双脉冲机制,本文亦做了初步探讨.  相似文献   
179.
三江平原沼泽湿地时空动态特征   总被引:3,自引:0,他引:3  
1IntroductionThe wetland ecosystem is the latest one understood by humans and it is the most seriously damaged ecosystem (Williams, 1991). The Sanjiang Plain, located in northeast China, is the largest concentrated area of freshwater wetland in China. Since the 1950s, large-scale reclamation of the marsh in the Sanjiang Plain has been started. According to statistics, the natural marsh has lost about 80% of its total area. The marsh resources in the Sanjiang Plain decreased greatly and the…  相似文献   
180.
JD-2F型井下地震计是在JD-2型深井地震仪的基础上,经过进一步的技术改进并引入电子反馈技术而研制成功的。它是为井下地震台的数字化改造而研制的,是JD-2型地震仪的替代产品。本文通过对比,重点介绍了它的主要技术指标及结构特点。  相似文献   
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