中国典型地区强震的地震学综合预测指标筛选及其在西南地区的检验   总被引：1，自引：0，他引：1  

周翠英  侯海峰  王红卫  柳凤兰  周元夫 《中国地震》2001,17(4):392-402

地震学定量综合预报方法(Seismological Quantitative Integrated Prediction Method,简称SQIP方法)是笔者等在"九五"攻关研究项目中使用华北地区资料和震例自行研制的一种基于多项地震学参数的综合预测方法.本文依据该方法的指标筛选法及规则,对中国大陆西南、华北、新疆3个地区7级以上强震进行了研究,提取了相应的强震地震学综合预测指标,并由此给出适用于中国大陆典型地区的强地震SQIP预测方法.同时在西南地区进行了该方法的时空扫描检验.  相似文献   

Determination of focal coordinates of near earthquakes in an area of unknown crustal parameters     

R. Gutdeutsch  K. Aric 《Pure and Applied Geophysics》1977,115(3):667-673

Summary A new computation method is described which determines the focal coordinates, theP _n-andP _G-velocity, the focal time and the Moho-depth in the case of near earthquakes. The method is provided especially for areas where the crustal parameters are insufficiently known. It presumes that the standard error ofP _n-andP _G-arrival times is a minimum. The problem turns out to represent the solution of a set of at least seven equations with seven unknown parameters. Four of these unknowns can be separated in advance. This leads to a considerable simplification. The three remaining unknowns are the focal coordinates. Their best fitting values are found by the gradient method. An example is presented which shows how errors can arise if the initial trial coordinate is chosen at an unfavourable position.  相似文献   

Crustal structure of Japan as derived from explosion seismic data     

Research Group For Explosion Seismology 《Tectonophysics》1973,20(1-4):129-132

Crustal structures of Japan were investigated under the Upper Mantle Project in three profiles, Kurayosi-Hanabusa, western Japan; Atumi-Noto, central Japan; Kesennuma-Oga, northeastern Japan. These investigations have revealed that the crust of Japan is of continental type. The variation of the crustal structure reflects the topography, especially the water depth; so the thinning of the crust occurs near the shore where the water depth increases rapidly. The velocity below the Mohorovi?i? discontinuity is smaller than 8.0 km/sec, but it is possible that a deeper layer with a velocity of over 8.0 km/sec may exist. The basaltic layer in central Japan, if existing at all, must be thin.  相似文献   

地震学中非线性预测方法的初步研究   总被引：2，自引：0，他引：2  

石特临  郭大庆 《地球科学进展》1995,10(3):273-277

介绍了近年来地震预测学中非线性理论和非线性方法的研究趋势和最新研究进展。在非线性数学模型的研究中，较为成功地将非线性门限模型，指数模型、具有长程关联自回归模型等应用于地震的中期预测上，在分形研究上，明确地取代了以往的一些经验结果，使对地震的活动的经验统计关系上升到分形的理论，在研究地震的动力学机制中，以多滑块－弹簧模型为代表，模拟地壳上地震断层运动机制和事实，建立了粘滑摩擦情况下的参数动力学方程。  相似文献   

Statistical estimation of corner frequency and its application to seismic event-identification     

G.R. Dargahi-Noubary 《Soil Dynamics and Earthquake Engineering》1998,17(5):297-309

A statistical method is proposed for estimation of the corner frequency. It is based on inference for a stochastic model whose short-term behavior resembles the established source time functions. Properties of the estimates are investigated and some numerical examples are presented. A discussion concerning earthquake–explosion discrimination and the way corner frequency can be related to the rate of zero-crossings is also included. The paper is concluded with some numerical examples.  相似文献   

关于做好云南省地震行业科研专项档案管理工作的思考     

林芳美 《国际地震动态》2015,(1)

简要分析了地震行业科研专项项目档案的特点,并提出从强化档案管理意识、建立相应的规章制度、档案工作与项目建设同步、加强档案业务指导、重视档案业务技能培训和做好档案验收工作6个方面,做好专项档案工作。  相似文献   

Seismic coda due to non-linear elasticity     

Klaus Bataille  Ignacia Calisto 《Geophysical Journal International》2008,172(2):572-580

Non-linear elastic response of rocks has been widely observed in laboratory, but very few seismic studies are reported in the literature, even though it is the most natural environment where this feature could be observed. Analytic solutions to the non-linear wave propagation phenomena are not readily available, and there is a need to use approximated techniques. It is clear that when a seismic wave propagates through a homogeneous non-linear elastic media, it will be perturbed by the non-linearity. This perturbation can be treated as a source of scattering, spreading the energy of the primary wave in space and time, contributing to the seismic coda. This is in some sense similar to the effect of heterogeneities. The properties of the coda due to the non-linearity depend on the amount of non-linearity and the seismic moment. Using a perturbation approach we calculate the amplitude of the scattered waves, and show that it can describe reasonably well the main features of real seismic codas.  相似文献   

Retrieval of local surface wave velocities from traffic noise – an example from the La Barge basin (Wyoming)     

M. Behm  Garrett M. Leahy  R. Snieder 《Geophysical Prospecting》2014,62(2):223-243

In regions where active source seismic exploration is constrained by limitations of energy penetration and recovery, cost and logistical concerns, or regulatory restrictions, analysis of natural source seismic data may provide an alternative. In this study, we investigate the feasibility of using locally‐generated seismic noise in the 2–6 Hz band to obtain a subsurface model via interferometric analysis. We apply this technique to three‐component data recorded during the La Barge Passive Seismic Experiment, a local deployment in south‐western Wyoming that recorded continuous seismic data between November 2008 and June 2009. We find traffic noise from a nearby state road to be the dominant source of surface waves recorded on the array and observe surface wave arrivals associated with this source up to distances of 5 kms. The orientation of the road with respect to the deployment ensures a large number of stationary points, leading to clear observations on both in‐line and cross‐line virtual source‐receiver pairs. This results in a large number of usable interferograms, which in turn enables the application of standard active source processing methods like signal processing, common offset stacking and traveltime inversion. We investigate the dependency of the interferograms on the amount of data, on a range of processing parameters and on the choice of the interferometry algorithm. The obtained interferograms exhibit a high signal‐to‐noise ratio on all three components. Rotation of the horizontal components to the radial/transverse direction facilitates the separation of Rayleigh and Love waves. Though the narrow frequency spectrum of the surface waves prevents the inversion for depth‐dependent shear‐wave velocities, we are able to map the arrival times of the surface waves to laterally varying group and phase velocities for both Rayleigh and Love waves. Our results correlate well with the known geological structure. We outline a scheme for obtaining localized surface wave velocities from local noise sources and show how the processing of passive data benefits from a combination with well‐established exploration seismology methods. We highlight the differences with interferometry applied to crustal scale data and conclude with recommendations for similar deployments.  相似文献   

Damage field and site effects: multidisciplinary studies of the 1964 earthquake series in Central Switzerland   总被引：1，自引：0，他引：1  

Stefan Fritsche  Donat Fäh  Brian Steiner  Domenico Giardini 《Natural Hazards》2009,48(2):203-227

Central Switzerland shows comparatively high seismic activity by Swiss standards. Many historical earthquakes are known and several of them caused damage. The last major event dates back to 1964 and has the characteristics of an earthquake swarm. Among dozens of felt shocks were two main shocks (Mw = 5 and 5.7) that moderately damaged a limited area with hundreds of buildings suffering loss. Our aim here was to reconstruct the damage field and to analyze whether it was influenced by site effects. Given the existence of a contemporary damage assessment and other historical sources, we could describe the damage field in detail. For about 95% of the affected buildings, we could reconstruct the location and extent of loss, using assessments from the European Macroseismic Scale (EMS 98). Spatial analysis of the resulting data showed that most losses were concentrated in the villages of Sarnen and Kerns. Damage to residential houses and barns was by far most frequent (90%), but expensive losses to the relatively few sacral buildings were responsible for almost 50% of the repair costs. We compared the damage data with deposit thickness and soil composition and carried out field experiments using H/V spectral ratios to measure the fundamental frequency of ground resonance at 75 sites to estimate the frequency band in which amplification occurs. Our results show that locations on both thick fluviatile sediments and large alluvial cones showed higher intensities than did other ground types. Moreover, at some sites, intensity was probably increased by a layer of weathered rock below thin deposits.  相似文献   

Evidence for lithospheric detachment in the central Andes from local earthquake tomography   总被引：4，自引：1，他引：3  

B. Schurr  A. Rietbrock  G. Asch  R. Kind  O. Oncken   《Tectonophysics》2006,415(1-4):203-223

Data from three temporary seismic networks were merged for tomographic inversion. Although the deployments did not coincide in time, spatial overlap was achieved by re-occupying existing sites. Travel times and t operators of about 1600 earthquakes were inverted for 3D models of ν_p, ν_p/ν_s and P-wave attenuation (Q_p^− 1). All three attributes provide a consistent image of the entire subduction zone on a lithospheric scale. The tomographic images reveal low velocities and high attenuation in the crust and mantle underlying the Western Cordillera and most of the Puna plateau, indicative of weak rheology and mostly asthenospheric mantle. In contrast, forearc and eastern foreland are characterized by high Q_p values, corresponding to cold temperatures in accordance with thermal models. In the backarc, between 23°S and 24°S, a high velocity, high Q_p structure beneath the Eastern Cordillera and eastern Puna is interpreted as detaching continental lithosphere that has been thickened in the orogenic process. South of this structure, the mantle is characterized by low velocities, high ν_p/ν_s ratios, and low Q_p values. Here it is believed that lithosphere originally underlying Andean crust has already been removed. This is supported by new estimates of crustal thickness and volcanic activity.  相似文献