共查询到19条相似文献，搜索用时 656 毫秒
1.
态矢量是一种中短期地震预测方法,通常在大地震发生之前,态矢量时间序列会发生明显的异常变化.在此基础上,进一步尝试根据震前应力场分布,提高态矢量的地震临界敏感性,震前库仑应力分布采用地震断层位错模型将滑移量反向滑移的方法计算,2008年汶川地震震前的态矢量研究表明,采用库仑应力算法得到的时间序列前兆变化更明显,对目标地震... 相似文献
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1970年以来中国大陆25次6.8级以上地震前态矢量异常特征研究 总被引：2，自引：0，他引：2
利用态矢量方法对中国大陆1970年以来25次6.8级以上地震进行了较为全面的分析研究, 结果表明, 19次地震前3年内态矢量出现明显异常, 其中10次地震发生前60天内态矢量有明显的变化, 只有6次地震前态矢量变化不明显。 由此认为态矢量方法对强震具有一定的中期和短临预测能力。 研究结果还表明, 相对于态矢量增量的模、 态矢量方向的改变等参量, 态矢量的模在震前的变化更为敏感, 此外, 对于相同震级的地震, 最佳扫描区域尺度大小不一, 并对这些现象进行了一定的解释。 相似文献
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态矢量方法的实验研究 总被引：5，自引：1，他引：5
在地震等灾变的发生之前，会出现一定的前兆现象。中通过实验方法对这些前兆现象之一的态矢量的异常变化进行了研究。实验使用声发射技术(Acoustic Emission)，对三轴应力条件下岩石试件内部微裂纹的产生和扩展进行了记录。实验结果表明在岩石试件最终破坏之前，表征态矢量的相关参量都发生了异常明显的变化，这表明态矢量的异常变化可以被用作为岩石等脆性材料灾变的前兆，使用态矢量方法可以对脆性材料的破坏乃至地震作出预测。 相似文献
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华东地区态矢量的研究 总被引：2，自引：0，他引：2
态矢量来源于统计物理学,是对连续场进行粗粒化描述的方法。尹祥础等把该方法移植到地震学中用以定量刻画地震活动性的演化,取得较好的结果。作者对华东地区1970年以来发生5级以上12次地震进行了分析,总结震前态矢量的变化情况,发现震前态矢量均有显著变化,为本地区地震趋势预测提供一定的参考价值。 相似文献
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用SVG实现基于 Web的地震数据图形化服务 总被引：1，自引：0，他引：1
SVG是一种基于XML的用来描述二维矢量的标志语言,是一种全新的矢量图形规范,为了能够对相关人员提供方便直观快捷的地震数据表现形式,本文对利用SVG实现地震数据图形化表示的方法进行了讨论与研究。 相似文献
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地磁短周期变化异常对中国中强地震的响应 总被引：11，自引：0，他引：11
我们考察了发生在中国的１１个具有代表性的地震后发现。地震前地磁短周期转换函数的帕金森矢量或韦氏矢量指向震中方向，转换函数│Ａ│或│Ｂ│值明显偏离正常值以及总误差δｚ显著增大，均为未来地震的发生和震中方向提供了判断依据。应用此法，我们成功地预报了Ｍｓ５．１地震。中国地震科技工作者认为，震前地磁短周期变化异常是客观存在的。物理基础是清楚的，是有希望的地震短临预报方法。 相似文献
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本文对地倾斜矢量用于地震异常识别的问题进行了讨论。在研究和讨论了矢量模概念的基础上,将其用于地倾斜矢量变化的稳定性判别和震兆识别的研究。本文利用矢量模研究了青海共和、景泰地震和大同地震前后,有关台站的地倾斜矢量的变化特征。结果表明,矢量的停滞打结可能是稳定的,因而未必是震兆,而剧变则可能是非稳定的,可作为异常的判别标志。 相似文献
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通过第四纪地壳运动降幅统计指标，即均化值Ｈ、标准差σ、非对称Ａｓ及峰态Ｋｕ，揭示工作区各亚区不同的地震动力学特征，从而为地震危险性评估与地球动力学研究提供一种定量的地质标志 相似文献
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提出了一种使用慢度矢量分量和偏振矢量计算变井源距垂直地震剖面(walkaway VSP)钻孔中接收点附近介质弱各向异性(WA)参数的方法.假定介质是任意弱各向异性介质,从一般公式中得到了只有一条观测剖面情况下的反演公式.如果知道了慢度矢量的垂直分量和偏振矢量,可以通过反演得到与剖面和钻孔所在平面相关的WA参数,反演过程不用进行射线追踪,与上覆介质无关.用合成数据检验了公式和方法的正确性,并把它们应用于在爪哇海地区得到的一条变井源距垂直地震剖面的弱各向异性参数反演中. 相似文献
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Yin Xiangchu 《中国地震研究》2004,18(3):263-270
The concept of state vector stems from statistical physics, where it is usually used to describe the evolution of a continuum field in its way of coarse-graining. In this paper, the state vector is employed to depict the evolution of seismicity quantitatively, and some interesting results are presented. The authors investigated some famous earthquake cases (e.g., the Haicheng earthquake, the Tangshan earthquake, the west Kunlun Mountains earthquake, etc.) and found that the state vectors evidently change prior to the occurrence of large earthquakes. Thus it is believed that the state vector can be used as a kind of precursor to predict large earthquakes. 相似文献
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YinXiangchu YuHuaizhong ZhangYongxian 《中国地震研究》2004,18(3):263-270
The concept of state vector stems from statistical physics, where it is usually used to describe the evolution of a continuum field in its way of coarse-graining. In this paper, the state vector is employed to depict the evolution of seismicity quantitatively, and some interesting results are presented The authors investigated some famous earthquake cases (e.g., the Haicheng earthquake, the Tangshan earthquake, the west Kunlun Mountains earthquake, etc.) and found that the state vectors evidently change prior to the occurrence of large earthquakes. Thus it is believed that the state vector can be used as a kind of precursor to predict large earthquakes. 相似文献
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State Vector: A New Approach to Prediction of the Failure of Brittle Heterogeneous Media and Large Earthquakes 总被引：2，自引：0，他引：2
Huai-zhong Yu Xiang-chu Yin Qing-yong Zhu Yu-ding Yan 《Pure and Applied Geophysics》2006,163(11-12):2561-2574
The concept of state vector stems from statistical physics, where it is usually used to describe activity patterns of a physical field in its manner of coarsegrain. In this paper, we propose an approach by which the state vector was applied to describe quantitatively the damage evolution of the brittle heterogeneous systems, and some interesting results are presented, i.e., prior to the macro-fracture of rock specimens and occurrence of a strong earthquake, evolutions of the four relevant scalars time series derived from the state vectors changed anomalously. As retrospective studies, some prominent large earthquakes occurred in the Chinese Mainland (e.g., the M 7.4 Haicheng earthquake on February 4, 1975, and the M 7.8 Tangshan earthquake on July 28, 1976, etc) were investigated. Results show considerable promise that the time-dependent state vectors could serve as a kind of precursor to predict earthquakes. 相似文献
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针对地震中城市桥梁震害状态具有较强的非线性、复杂性的特点,采用了具有RBF核函数的最小二乘支持向量机(LS-SVM)算法。在大量收集我国地震中城市桥梁震害资料的基础上,将此算法引入桥梁的震害预测中,选取了地震烈度、上部结构、地基失效程度、支座类型、墩台高度、桥梁跨数和场地类别等因素作为模型的特征输入向量,建立了最小二乘支持向量机的桥梁震害预测模型。通过反复地样本训练及模型参数设置,仿真结果表明,该方法具有一定的准确度和可行性。基于最小二乘支持向量机的桥梁震害预测方法是一种可以用于地震中桥梁震害预测的良好方法。 相似文献
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This paper deals with Rayleigh–Schuster’s hodographs, intended for the detailed investigation of changes in the phase of quasiperiodic signals in time series. The hodographs are also known as the phasor-walkout method. A procedure of conditional vector normalization is proposed: it takes into account the vector amplitude for each period under consideration. The procedure considerably improves the robustness and stability of the hodograph approach to changes in the character of the processed data distributions and to various defects in the data. For example, when analyzing the earthquake catalog, the procedure strongly diminishes the influence of the event clustering caused, in particular, by swarms of earthquakes with comparable magnitude and the aftershock sequences of strong earthquakes. At the first stage, we calculate the vector sums (resulting vectors) for each period under investigation throughout the time series duration. For example, investigating diurnal periodicity of earthquakes, we first calculate the resulting vectors for each day of the observation. The further analysis of resulting vectors for each period throughout the time series duration can be performed with different procedures. We compare three procedures for normalization of the obtained resulting vectors, which are as follows: (1) th traditional one, preserving the real signal amplitude; (2) that with reduction of the obtained resulting vectors to the unit vector (phasor); and (3) that with conditional vector normalization, taking into account the amplitude of resulting vectors for each period throughout the time series duration. The third procedure diminishes the possible instability in some special distributions of the investigated data when the resulting vector for a period is close to zero. The procedures are compared using model signals and samples from real earthquake catalogs. All the procedures used give close results when processing random time series. 相似文献
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针对影响地震伤亡人数的评价指标数量较多且各指标之间存在着复杂的非线性关系,运用机器学习理论,提出了基于支持向量机(Support Vector Machine)的地震伤亡人数预测模型;首先利用主成分分析法(Principle Component Analysis)对7个地震死亡人数影响指标进行数据降维,然后对提取出的主成分进行归一化处理,将归一化的主成分数据作为预测模型的输入向量,将地震伤亡人数作为预测模型的输出向量;以27个地震伤亡实例作为学习样本进行训练,运用网格搜索法(Grid Search Method)寻优获得最优支持向量机参数,最终建立基于PCA-GSM-SVM的地震死亡人数预测模型,并对5组样本进行死亡人数预测。结果表明:PCA-GSM-SVM模型的最小误差、最大误差和平均误差分别为5.12%、15.7%和9.16%,其平均误差相比于GSM-SVM模型和SVM模型分别降低6.51%和7.11%,因此PCA-GSM-SVM模型预测精度较高,可在工程实际中推广。 相似文献
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Introduction The MS=8.1 earthquake occurred in west of the Kunlun Pass on November 14, 2001. It is the greatest earthquake occurred in China since the last half of the century and is an important event in recent seismic history of China. Some specialists consider that the earthquake occurred in the area where the earthquake monitoring capability is lowest in Chinese mainland; no striking precursory seismicity was found. The study on the precursory seismicity before the earthquake has not b… 相似文献
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Ｃｅｌｌｕｌａｒ ａｕｔｏｍａｔｉｏｎ ｍｏｄｅｌ ｏｆ ｆａｕｌｔｓ ａｎｄ ａｌｇｏｒｉｔｈｍｉｃ ｃｏｍｐｌｅｘｉｔｙ（陆远忠）（吕悦军）Ｃｅｌｌｕｌａｒａｕｔｏｍａｔｉｏｎｍｏｄｅｌｏｆｆａｕｌｔｓａｎｄａｌｇｏｒｉｔｈｍｉｃｃｏｍｐｌｅｘｉ... 相似文献