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研究了天水地震台附近地区2次小地震的地震前兆,发现地电阻率、自然电位、地下水位、水温、水氡、地温、地应力在震前都有变化。 相似文献
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2006年7月4日河北文安县发生了Ms5.1地震,有6个地电场观测台布设在北京周围.本文阐述了地电场多极距观测系统的噪音识别原理及其在地电场数据分析中的应用方法.通过对首都圈6个地电场台观测资料的研究分析,在所选出的众多震前地电场异常信号中逐一排除,最后选定的5组地电场异常信号基本上被认为是震前地电场前兆异常信号.结果表明:①文安Ms5.1地震前存在着地电场异常前兆信号;②文安地震前地电场异常前兆信号的出现存在着"敏感点"效应;③地电场异常前兆信号在不同的台站存在着不同步出现的现象,并且异常结束至发震时间间隔也不同;④离震中区较近的宝坻台记录到的震前地电场异常幅度较小,而离震中区较远的昌黎台记录到的震前地电场异常幅度则较大. 相似文献
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震前电磁场和大地自电位的异常是重要的地震前兆现象.在零磁空间对超低频段的磁场和自电位的变化进行了岩石破裂的实验研究,细致地揭示出电场、磁场出现异常变化的全过程,对深入认识超低频电磁信号的微观机理具有重要的意义.实验发现,岩石受力后应变、电位和磁场的缓慢变化在空间分布上是首先在近破裂源处出现,继而随裂纹的发展而改变位置;在时间序列上先出现自电位异常,然后是超低频磁场的变化;在异常形态上,超低频电磁信号呈现出早期、中期、晚期3个阶段的明显差异.研究表明,岩石微破裂引起裂隙尖端处的电荷分离. 静电荷在局部区域的积累和运移,导致了自电位的脉冲状变化;而在主破裂阶段,积累电荷的急速运动形成瞬间电流,激发了脉冲式的磁场异常.本文详细介绍了这一综合实验的技术步骤和观测结果,并对地震电磁前兆的微观机理进行了探讨. 相似文献
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2006年7月4日河北文安县发生了MS5.1地震,有6个地电场观测台布设在北京周围。本文阐述了地电场多极距观测系统的噪音识别原理及其在地电场数据分析中的应用方法。通过对首都圈6个地电场台观测资料的研究分析,在所选出的众多震前地电场异常信号中逐一排除,最后选定的5组地电场异常信号基本上被认为是震前地电场前兆异常信号。结果表明:①文安MS5.1地震前存在着地电场异常前兆信号;②文安地震前地电场异常前兆信号的出现存在着ldquo;敏感点rdquo;效应;③地电场异常前兆信号在不同的台站存在着不同步出现的现象,并且异常结束至发震时间间隔也不同;④离震中区较近的宝坻台记录到的震前地电场异常幅度较小,而离震中区较远的昌黎台记录到的震前地电场异常幅度则较大。 相似文献
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5.1震前大气电场异常与地震
灾害性地震的巨大破坏力不仅使人们对地震产生恐惧感,也使众多科研人员对地震和地震预测观测研究产生了农厚的兴趣.由于大气电场与震前动物异常和地光间可能存在联系,以及震前观测到的大气电场异常现象,唐山大地震发生后,我国不少科研院所和社会人士根据国内外已有的知识和经验,开始用观测大气电场变化的方法探索地震短临前兆异常信息. 相似文献
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本文应用归一化变化速率(NVRM)方法,研究了2017年九寨沟M_S7.0地震周边800km范围内25个地电阻率台站2012—2018年的连续观测数据,分析了震中区周围的地电阻率时、空演化过程.结果显示:(1)25个台站中共有14个台站在震前出现了地电阻率变化,结合本次地震震源机制等分析其时空变化,认为邻近地震破裂带的临夏、通渭、武都和宝鸡台地电阻率在震前出现了下降—折返回升型的变化,符合前人已总结的强地震前地电阻率的变化过程.(2)地震发生前震中区周围大区域内出现了地电阻率负异常变化,且以震中区为中心呈条带分布,异常区的长轴方向与地震断裂带走向或地震烈度分布的长轴方向几乎垂直,与地震主压应力轴方向吻合.本文认为九寨沟M_S7.0强震发生之前,震中区周围出现的区域性地电阻率异常空间丛集现象是很好的中期和短临前兆;地电阻率震前异常动态演化、各向异性等特征对认识本次强震发震断层活动以及震源区应力场分布有启示意义. 相似文献
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M. N. French R. L. Bras W. F. Krajewski 《Stochastic Environmental Research and Risk Assessment (SERRA)》1992,6(1):27-45
A procedure for short-term rainfall forecasting in real-time is developed and a study of the role of sampling on forecast ability is conducted. Ground level rainfall fields are forecasted using a stochastic space-time rainfall model in state-space form. Updating of the rainfall field in real-time is accomplished using a distributed parameter Kalman filter to optimally combine measurement information and forecast model estimates. The influence of sampling density on forecast accuracy is evaluated using a series of a simulated rainfall events generated with the same stochastic rainfall model. Sampling was conducted at five different network spatial densities. The results quantify the influence of sampling network density on real-time rainfall field forecasting. Statistical analyses of the rainfall field residuals illustrate improvement in one hour lead time forecasts at higher measurement densities. 相似文献
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《地震工程与工程振动(英文版)》2014,(4)
正This journal is established by the Institute of Engineering Mechanics(IEM),China Earthquake Administration,to promote scientific exchange between Chinese and foreign scientists and engineers so as to improve the theory and practice of earthquake hazards mitigation,preparedness,and recovery.To accomplish this purpose,the journal aims to attract a balanced number of papers between Chinese and 相似文献
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George W. Housner 《地震工程与工程振动(英文版)》2008,7(2):I0001-I0001
Destructive earthquakes have caused great damage in China and the United States and collapsing buildings havecaused many deaths and injuries. The field of earthquake engineering studies earthquake hazards, the occurrence ofearthquakes of various magnitudes, the nature of the ground shaking during an earthquake, the vibration of structuresduring earthquakes, the strengthening of existing structures and the design of new structures to be earthquake resistant,and finally, how to cope with earthquake damage and restore a city to normal functioning. Such efforts are in progressin both countries, but unfortunately, the language barrier interferes with the free flow of information between China andthe Untied States. It would be mutually beneficial if some means could be developed to promote the exchangeof information across the Pacific Ocean. This new journal has been established for this purpose and its success willbe an important step in promoting earthquake engineering in China and the United States. 相似文献
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《国际泥沙研究》2014,(4)
正President:Giampaolo Di Silvio,Italy Vice Presidents:Ulrich C.E.Zanke,Germany Zhao-yin Wang,China The World Association for Sedimentation and Erosion Research(WASER),inaugurated on Oct.19,2004,is an independent non-governmental,non-profit organization.The mission of WASER is to promote international co-operation on the study 相似文献
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JianCheng Shi 《中国科学:地球科学(英文版)》2014,57(10):2281-2282
正Global Change includes climate change and other environmental changes caused by the joint interaction among various layers of Earth. From the positive side, global change provides new opportunities to human and other living forms on Earth. In the meantime, it creates tremendous challenges and negative impact. At present, the negative impacts have reached all primary processes of the global ecosystem and every aspect of human society, especially causing degradation of the ecosystem. For instance, intensive deforestation causes decline of biodiversity; global warming causes sea level rise and increases 相似文献