共查询到20条相似文献，搜索用时 937 毫秒
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Qian Wang Xinxin Yin Changsheng Jiang Cong Jiang Yan Zhang Hongyu Zhai Yanbao Zhang Guijuan Lai Fengling Yin 《地震科学（英文版）》2021,34(3):286-298
In the new types of industrial activities including unconventional energy extraction associated with shale gas and hot dry rock, gas reservoir operations, CO2 geological storage, undergoing research on induced earthquake forecasting has become one of the forward positions of current seismology. As for the intense actual demand, the immature research on induced earthquake forecasting has already been applied in pre-assessment of site safety and seismic hazard and risk management. This work will review systematically recent advances in earthquake forecasting induced by hydraulic fracturing during industrial production from four aspects: earthquake occurrence probability, maximum expected magnitude forecasting, seismic risk analysis for engineering and social applications and key scientific problems. In terms of earthquake occurrence probability, we introduce statistical forecasting models such as an improved ETAS and non-stationary ETAS and physical forecasting models such as Seismogenic Index (SI) and hydro-mechanism nucleation. Research on maximum expected magnitude forecasting has experienced four stages of linear relationship with net injection volume of fluid, power exponential relationship and physical forecasting regarding fault parameters. For seismic risk analysis, we focus on probabilistic seismic hazard assessment and quantitative geological susceptibility model. Furthermore, this review is extended to key scientific problems that contain obtaining accurate fault scale and environmental stress state of reservoir, critical physical process of runaway rupture, complex mechanism of fault activation as well as physical mechanism and modeling of trailing effect. This work in understanding induced earthquake forecasting may contribute to unconventional energy development and production, seismic hazard mitigation, emergency management and scientific research as a reference. 相似文献
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Zhou Bengang 《中国地震研究》2004,18(2):200-211
Through the statistical analysis of earthquake distribution along 51 strike-slip active fault segments on the Chinese continent, we found that strong earthquake distribution along the seismogenic fault segments is inhomogeneons and the distribution probability density p (K) canbe stated as p(K)=1.1206e^3.947k^2 in which K = S/(L/2), S refers to the distance from earthquake epicenter to the center of a fault segment, L is the length of the fault segment. The above model can be utilized to modify the probability density of earthquake occurrence of the maximum magnitude interval in apotential earth quake source. Nevertheless, it is only suitable for thosepotential earthquake sources delineated along a single seismogenic fault. This inhomogeneons model has certain effects on seismic risk assessment, especially for those potential earthquake sources with higher earthquakerates of the maximum magnitude interval. In general, higher reoccurrence rate of the maximum magnitude interval and lower exceeding probability level may bring larger difference of the results in seismic risk analysis by adopting the inhomogeneons model, the PGA values increase inner the potential earthquake source, but reduce near the vicinity and out of the potential earthquake source. Taking the Tangyin potential earthquake source as an example, with exceeding probability of 10% and 2% in 50 years, the difference of the PGA values between inhomogeneons model and homogenous models can reach 12 %. 相似文献
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Vincenzo Convertito Iunio Iervolino Aldo Zollo Gaetano Manfredi 《Soil Dynamics and Earthquake Engineering》2008,28(6):492-505
The development and implementation of an earthquake early warning system (EEWS), both in regional or on-site configurations can help to mitigate the losses due to the occurrence of moderate-to-large earthquakes in densely populated and/or industrialized areas. The capability of an EEWS to provide real-time estimates of source parameters (location and magnitude) can be used to take some countermeasures during the earthquake occurrence and before the arriving of the most destructive waves at the site of interest. However, some critical issues are peculiar of EEWS and need further investigation: (1) the uncertainties on earthquake magnitude and location estimates based on the measurements of some observed quantities in the very early portion of the recorded signals; (2) the selection of the most appropriate parameter to be used to predict the ground motion amplitude both in near- and far-source ranges; (3) the use of the estimates provided by the EEWS for structural engineering and risk mitigation applications.In the present study, the issues above are discussed using the Campania–Lucania region (Southern Apennines) in Italy, as test-site area. In this region a prototype system for earthquake early warning, and more generally for seismic alert management, is under development. The system is based on a dense, wide dynamic accelerometric network deployed in the area where the moderate-to-large earthquake causative fault systems are located.The uncertainty analysis is performed through a real-time probabilistic seismic hazard analysis by using two different approaches. The first is the Bayesian approach that implicitly integrate both the time evolving estimate of earthquake parameters, the probability density functions and the variability of ground motion propagation providing the most complete information. The second is a classical point estimate approach which does not account for the probability density function of the magnitude and only uses the average of the estimates performed at each seismic station.Both the approaches are applied to two main towns located in the area of interest, Napoli and Avellino, for which a missed and false alarm analysis is presented by means of a scenario earthquake: an M 7.0 seismic event located at the centre of the seismic network.Concerning the ground motion prediction, attention is focused on the response spectra as the most appropriate function to characterize the ground motion for earthquake engineering applications of EEWS. 相似文献
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Bussgang算法是针对褶积盲源分离问题提出的,本文将其用于地震盲反褶积处理.由于广义高斯概率密度函数具有逼近任意概率密度函数的能力,从反射系数序列的统计特征出发,引入广义高斯分布来体现反射系数序列超高斯分布特征.依据反射系数序列的统计特征和Bussgang算法原理,建立以Kullback-Leibler距离为非高斯性度量的目标函数,并导出算法中涉及到的无记忆非线性函数,最终实现了地震盲反褶积.模型试算和实际资料处理结果表明,该方法能较好地适应非最小相位系统,能够同时实现地震子波和反射系数估计,有效地提高地震资料分辨率. 相似文献
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The semi‐automated detection of objects has been quite successful in detecting various types of seismic object, such as chimneys. The same technique can be applied successfully to detect faults in 3D seismic data. We show that several different attributes – among others, similarity, frequency and curvature, all of which potentially enhance the visibility of faults – can be combined successfully by an artificial neural network. This results in a fault ‘probability’ cube in which faults are more continuous and noise is suppressed compared with single‐attribute cubes. It is believed that the fault‐cube can be improved further by applying image‐processing techniques to enhance the fault prediction. 相似文献
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Bayesian inversion of time‐lapse seismic data for the estimation of static reservoir properties and dynamic property changes 
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下载免费PDF全文 Seismic conditioning of static reservoir model properties such as porosity and lithology has traditionally been faced as a solution of an inverse problem. Dynamic reservoir model properties have been constrained by time‐lapse seismic data. Here, we propose a methodology to jointly estimate rock properties (such as porosity) and dynamic property changes (such as pressure and saturation changes) from time‐lapse seismic data. The methodology is based on a full Bayesian approach to seismic inversion and can be divided into two steps. First we estimate the conditional probability of elastic properties and their relative changes; then we estimate the posterior probability of rock properties and dynamic property changes. We apply the proposed methodology to a synthetic reservoir study where we have created a synthetic seismic survey for a real dynamic reservoir model including pre‐production and production scenarios. The final result is a set of point‐wise probability distributions that allow us to predict the most probable reservoir models at each time step and to evaluate the associated uncertainty. Finally we also show an application to real field data from the Norwegian Sea, where we estimate changes in gas saturation and pressure from time‐lapse seismic amplitude differences. The inverted results show the hydrocarbon displacement at the times of two repeated seismic surveys. 相似文献
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本文基于地层反射系数非高斯的统计特性,在反褶积输出单位方差约束下,将反褶积输出的负熵表示为非多项式函数,作为盲反褶积的目标函数,然后采用粒子群算法优化目标函数寻找最佳反褶积算子,实现地震信号的盲反褶积.数值模拟和实际资料处理结果表明,与传统反褶积方法相比,本文方法同时适应于最小相位子波及混合相位子波的反褶积,能够更好地从地震数据中估计反射系数,有效拓宽地震资料的频谱,得到高分辨率的地震资料. 相似文献
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摘要：地震地表破裂是强地震活动中沿发震断层在地表形成的位移,它是包括震源因素、传播途径因素、场地地质条件因素等多种复杂因素的综合作用产物。地震地表破裂可以定量地加以描述。在假定基岩介质具有各项均匀刚性的前提下,对于一般的场地,地震地表破裂的危险性（概率P）大致可以确定为场地地震危险性（P1）、断层（P2）、场地第四系覆盖层（P3）的函数,即P=3Пi=1Pi.Pi值的确定可以通过多种途径来实现,本文在Pi值的确定过程中,以场地所在潜在震源区震级上限（Mu）为指标,P1=1．5874（Mu-6）-1;P2表示为断层发育状况、活动程度和断层最新活动性质的概率指数,P2=3Пi=1P2i.P3=nПi=1kiwi,wi为分解的第i均质土层（i=1,2,…,n）对地震破裂的衰减系数,ki为破裂通过第i均质土层（i=1,2,…,n）与其下土层临界面的破裂传播折射损耗率。通过上面的计算可以得到一般场地条件下地震地表破裂的危险性估计,这一估计是相对保守的估计。 相似文献
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储层物性参数是储层描述的重要参数,常规的基于贝叶斯理论的储层物性参数反演方法大多是通过反演获得的弹性参数进一步转换而获得物性参数,本文提出一种基于弹性阻抗数据预测储层物性参数的反演方法.该方法主要通过建立可以表征弹性阻抗与储层物性参数之间关系的统计岩石物理模型,联合蒙特卡罗仿真模拟技术,在贝叶斯理论框架的指导下,应用期望最大化算法估计物性参数的后验概率分布,最终实现储层物性参数反演.经过模型测试和实际资料的处理,其结果表明本文提出的方法具有预测精度高,稳定性强,横向连续性好等优点. 相似文献
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It is generally accepted that both deterministic and statistical approaches are useful for the characterization of earthquake hazard. Although the most reliable estimates of seismic hazard can only be based on an improved understanding of the earthquake mechanism, efficient utilization of the appropriate methods provided by recent statistical theories is also important in seismic risk analysis. This is especially true in regions where the connection between seismicity and geologic structure is tenuous at best. We are particularly interested in developing better statistical treatments of data for regions with little known seismic activity. To this end, we have applied three statistical methods to the historical record of seismicity in relatively quiet regions of eastern North America. These are: (1) the threshold method for tail inference, a new theory for modeling earthquakes with sizes above a given threshold, (2) the ‘bootstrap’ technique in which the characteristics of an unknown population are simulated by replacing the true population by an estimated one, and (3) a technique to estimate the number of earthquakes below a given size, in order to compensate for the under-reporting of small earthquakes in most catalogs. A combination of these techniques has been used to estimate the probabilities of future large earthquakes for the regions studied. Because of limitations imposed by existing catalogs, the size estimate used has been maximum intensity. 相似文献
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The analysis of seismic hazards relies on the statistical analysis of historical seismic data and the instrumental seismic catalog to obtain the regional earthquake recurrence interval and earthquake probability. The accuracy of analysis thus depends strongly on the completeness of the seismic data used. However, available seismic catalogs are too short or incomplete for the reliable analysis of the statistical characteristics of earthquakes. If a long-term synthetic seismic catalog can be generated using a physics-based numerical simulation, and the simulation results match the crustal deformation, seismicity, and other observations,then such a synthetic catalog helps us to further understand the characteristics of seismic activity and analyze the regional seismic hazard. In this paper, taking the northeastern Tibetan Plateau as a case study, we establish a three-dimensional visco-elastoplastic finite-element model to simulate earthquake cycles and the spatiotemporal evolution of earthquakes on the model fault system and obtain a seismic catalog on a time scale of tens of thousands of years. On the basis that the model satisfies the regional geodynamics of the northeastern Tibetan Plateau, we analyze seismicity on the northeastern Tibetan Plateau using the simulated synthetic earthquake catalog. The characteristics of earthquake recurrence at different locations and different magnitudes, and the long-term average probability of earthquake occurrence within the fault system on the northeastern Tibetan plateau are studied. The results are a reference for regional seismic hazard assessment and provide a basis for the physics-based numerical prediction of earthquakes. 相似文献
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Seismic risk assessment requires adoption of appropriate models for the earthquake hazard, the structural system and for its performance, and quantification of the uncertainties involved in these models through appropriate probability distributions. Characterization of the seismic hazard comprises undoubtedly the most critical component of this process, the one associated with the largest amount of uncertainty. For applications involving dynamic analysis this hazard is frequently characterized through stochastic ground motion models. This paper discusses a novel, global sensitivity analysis for the seismic risk with emphasis on such a stochastic ground motion modeling. This analysis aims to identify the overall (i.e. global) importance of each of the uncertain model parameters, or of groups of them, towards the total risk. The methodology is based on definition of an auxiliary density (distribution) function, proportional to the integrand of the integral quantifying seismic risk, and on comparison of this density to the initial probability distribution for the model parameters of interest. Uncertainty in the rest of the model parameters is explicitly addressed through integration of their joint auxiliary distribution to calculate the corresponding marginal distributions. The relative information entropy is used to quantify the difference between the compared density functions and an efficient approach based on stochastic sampling is introduced for estimating this entropy for all quantities of interest. The framework is illustrated in an example that adopts a source-based stochastic ground motion model, and valuable insight is provided for its implementation within structural engineering applications. 相似文献
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长波长假设条件下,各向同性背景地层中发育一组平行排列的垂直裂缝可等效为具有水平对称轴的横向各向同性（HTI）介质.基于不同观测方位的岩石地震响应特征变化,宽方位地震数据不仅可实现裂缝岩石弹性参数与各向异性参数的预测,同时也蕴含着丰富的孔隙度等储层物性参数信息.本文结合实际地震资料提出了贝叶斯框架下岩石物理驱动的储层裂缝参数与物性参数概率地震联合反演方法,首先基于AVAZ反演裂缝岩石的弹性参数与各向异性参数,并在此基础上通过统计岩石物理模型表征孔隙度、裂缝密度等各向异性介质储层参数与裂缝岩石参数的相互关联,并采用马尔科夫链蒙特卡洛（MCMC）抽样方法进行大量样本的随机模拟,使用期望最大化（EM）算法估计后验条件概率分布,最终寻找最大后验条件概率对应的孔隙度、裂缝密度等HTI裂缝介质储层参数即为反演结果.测井及实际地震数据处理表明,该方法能够稳定合理地从方位地震资料中获取裂缝岩石弹性参数与各向异性参数,并提供了一种较为可靠的孔隙度、裂缝密度等裂缝介质储层参数概率地震反演方法. 相似文献
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地震子波估计是地震资料处理和解释中的一个关键问题,子波估计的可靠性会直接影响反褶积和反演的准确度.现有的子波估计方法分为确定型和统计型两种类型,本文通过结合这两类方法,利用确定型的谱分析法和统计型的偏度最大化方法,分别提取时变子波的振幅和相位信息,得到估计的时变子波.这种方法不需要对子波进行任何时不变或相位等的假设,具有对时变相位的估计能力.进而利用估计时变子波进行非稳态反褶积,提高地震记录的保真度,为精细储层预测和描述提供高质量的剖面.理论模型试算验证了方法的可行性,通过实际地震资料的处理应用,表明该方法能有效地提取出子波时变信息. 相似文献
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为实现从注重灾后救助向注重灾前预防转变,如何提高地震灾害监测预警和风险防范能力成为我们关注的重点.本文给出了国际上GNSS位移记录、强震动加速度记录、测震速度记录在地震预警中的应用现状,并总结了各自的特点,归纳出围绕高频GNSS地震学在震级与破裂过程实时反演中的几个需要进一步研究的关键问题：（1）引入北斗系统,基于高频GNSS（GPS/BDS）双系统的实时位移解算方法来提高实时单站位移解算精度,使实时解算精度达到厘米级;（2）开展强震仪加速度记录基线偏移校正研究,弥补地震近场GNSS站密度不足问题;（3）强震仪加速度记录与GNSS位移记录特点不同,开展强震仪加速度数据与GNSS位移数据实时融合处理研究,快速获得包含丰富地震形变和速率的波形数据;（4）测震学方法可快速估算震级,但是在强震发生时会出现震级饱和现象,造成震级估算偏低.需要开展基于GNSS位移时间序列的多种方法相结合的实时震级估算方法研究,通过与地震学方法比较和结合,来得到精度高、计算快的震级估值算法;（5）基于高频GNSS、断层初始模型快速选取、断层尺度、参数自适应调整是快速判断断层破裂方向的基础,在断层破裂过程自适应准实时反演算法方面需要进一步加强.通过国内外研究现状调研、分析,表明基于高频GNSS地震学的震级快速确定、震源破裂过程准实时反演算法的发展将对我国地震预警系统从"二网融合"到"三网融合"提供坚实的技术支撑. 相似文献
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准时间可预报复发行为与断裂带分段发震概率估计 总被引：7，自引：0，他引：7
反不确定性引入“时间可预报模式”，可将一次地震之后的平静时间表示成与这次地震位错量在小呈正相关的随机变量。称这种带有不确定性的地震原地复发行为为“准时间可预报行为”。对于历史地震资料，准时间可预报复发行为可由地震后平静时间的对数与地震烈度的回归方程。文中给出了估计一条枯断裂带不同段落以上一次地震烈度值为背景的平均复发时间间隔的方法，以及可用 于对未来地震潜势进行不确定评价的实时概率模型，并以鲜水河 相似文献
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Amplitude variations with offset or incident angle (AVO/AVA) inversion are typically combined with statistical methods, such as Bayesian inference or deterministic inversion. We propose a joint elastic inversion method in the time and frequency domain based on Bayesian inversion theory to improve the resolution of the estimated P- and S-wave velocities and density. We initially construct the objective function using Bayesian inference by combining seismic data in the time and frequency domain. We use Cauchy and Gaussian probability distribution density functions to obtain the prior information for the model parameters and the likelihood function, respectively. We estimate the elastic parameters by solving the initial objective function with added model constraints to improve the inversion robustness. The results of the synthetic data suggest that the frequency spectra of the estimated parameters are wider than those obtained with conventional elastic inversion in the time domain. In addition, the proposed inversion approach offers stronger antinoising compared to the inversion approach in the frequency domain. Furthermore, results from synthetic examples with added Gaussian noise demonstrate the robustness of the proposed approach. From the real data, we infer that more model parameter details can be reproduced with the proposed joint elastic inversion. 相似文献