新疆轮台县经济开发区工程场地地震危险性分析     

《地球科学与环境学报》1995,(4)

本文分析了新疆轮台县开发场区外围３００ｋｍ范围内的区域地震活动性及地震地质背景，划分出８个潜在震源，采用Ａ．Ｈ－Ｓ．Ａｕｇ提出的断层－破裂模型对场区作了地震危险性分析。计算表明，在给定５０年工程期限，超越概率为１０％时的场地烈度为７．３，相应最大地震影响系数为０．１５８。该结果可作为抗震设计的依据。  相似文献   

地震波散射研究的新进展——第25届IASPEI大会S13专题报告会“地震波散射与衰减”简介          下载免费PDF全文

吴如山 《地球物理学报》1990,(3)

本文以IASPEI的“地震波的散射与衰减”专题报告会为主,评述了近几年在地震波散射方面的研究进展.述评所涉及的方面有:1.关于地震尾波的起源;2.大震前尾波包络的前兆性变化;3.地震尾波包络衰降的机理;4.区分散射和吸收的新方法;5.新领域的开拓和研究.  相似文献   

Pathways to seismic hazard evaluation: Extreme and characteristic earthquakes in areas of low and high seismicity   总被引：4，自引：0，他引：4  

Paul W. Burton 《Natural Hazards》1990,3(3):275-291

The general philosophy of seismic hazard evaluation described here is appropriate for selection of seismic input to regional earthquake engineering codes prior to detailed on-site inspections and geotechnical assessments. Some probabilistic seismic hazard methodologies which can be applied in areas of low and high seismicity, are briefly described to emphasise the main equations with specimen results. Three aspects of hazard assessment are explored by different pathways. These include the analysis of regional earthquake catalogues to obtain magnitude recurrence, particularly using Gumbel extreme value statistics. This is extended to assess ground shaking hazard which is usually sought by earthquake engineers. Thirdly, the concept of earthquake perceptibility is developed, leading to the identification of an earthquake magnitude or type which is characteristic of a region. This most perceptible earthquake is most likely to be felt at any site in a region and provides an earthquake selection criterion which can be used in aseismic design of noncritical structures. Because there are several methods of seismic hazard evaluation, the view is expressed that it is sensible for practical purposes to seek results from different methods or different pathways to the hazard evaluation.Paper presented at the Commission of the European Communities' School on Earthquake Hazard Evaluation, Athens, and at the 21st General Assembly of the European Seismological Commission, held in Sofia, 1988.Now at School of Environmental Sciences, University of East Anglia, University Plain, Norwich NR4 7TJ, U.K.  相似文献   

Neo-deterministic definition of seismic input for residential seismically isolated buildings   总被引：1，自引：1，他引：0  

Elisa Zuccolo  Franco Vaccari  Antonella Peresan  Alberto Dusi  Alessandro Martelli  Giuliano F. Panza   《Engineering Geology》2008,101(3-4):89-95

This paper deals with the neo-deterministic definition of the seismic input in the municipality of Nimis (Italy), aimed at the design of residential seismically isolated buildings. The seismic input is defined by the computation of realistic synthetic seismograms considering different levels of detail for the earthquake source, both for a bedrock model and taking into account the specific site conditions. The horizontal response spectrum, calculated in the centre of the municipality by modelling the most dangerous source, advises against the construction of a building with a fixed base, but it is compatible with the seismic isolation, and it has been, therefore, used for the design of a residential seismically isolated building. The maximum displacement for the isolation system has been estimated about 17 cm, a value much lower than that provided by the code design response spectrum (28 cm). The importance of the realistic modelling, which permits the generalization of empirical observations by means of, physically sound, theoretical considerations, is evident, as it allows for the optimisation of the structural design with respect to the site of interest.  相似文献   

The structure of the lower crust at the Argentine continental margin, South Atlantic at 44°S     

Michael Schnabel  Dieter Franke  Martin Engels  Karl Hinz  Snke Neben  Volkmar Damm  Stefan Grassmann  Hugo Pelliza  Paulo Ricardo Dos Santos 《Tectonophysics》2008,454(1-4):14-22

It is well established that the Argentine passive margin is of the rifted volcanic margin type. This classification is based primarily on the presence of a buried volcanic wedge beneath the continental slope, manifested by seismic data as a seaward dipping reflector sequence (SDRS). Here, we investigate the deep structure of the Argentine volcanic margin at 44°S over 200 km from the shelf to the deep oceanic Argentine Basin. We use wide-angle reflection/refraction seismic data to perform a joint travel time inversion for refracted and reflected travel times. The resulting P-wave velocity-depth model confirms the typical volcanic margin structure. An underplated body is resolved as distinctive high seismic velocity (v_p up to 7.5 km/s) feature in the lower crust in the prolongation of a seaward dipping reflector sequence. A remarkable result is that a second, isolated body of high seismic velocity (v_p up to 7.3 km/s) exists landward of the first high-velocity feature. The centres of both bodies are 60 km apart. The high-velocity lower-crustal bodies likely were emplaced during transient magmatic–volcanic events accompanying the late rifting and initial drifting stages. The lateral variability of the lower crust may be an expression of a multiple rifting process in the sense that the South Atlantic rift evolved by instantaneous breakup of longer continental margin segments. These segments are confined by transfer zones that acted as rift propagation barriers. A lower-crustal reflector was detected at 3 to 5 km above the modern Moho and probably represents the lower boundary of stretched continental crust. With this finding we suggest that the continent–ocean boundary is situated 70 km more seaward than in previous interpretations.  相似文献   

Collision tectonics of the Central Indian Suture zone as inferred from a deep seismic sounding study     

D.M. Mall  P.R. Reddy  W.D. Mooney   《Tectonophysics》2008,460(1-4):116-123

The Central Indian Suture (CIS) is a mega-shear zone extending for hundreds of kilometers across central India. Reprocessing of deep seismic reflection data acquired across the CIS was carried out using workstation-based commercial software. The data distinctly indicate different reflectivity characteristics northwest and southeast of the CIS. Reflections northwest of the CIS predominantly dip southward, while the reflection horizons southeast of the CIS dip northward. We interpret these two adjacent seismic fabric domains, dipping towards each other, to represent a suture between two crustal blocks. The CIS itself is not imaged as a sharp boundary, probably due to the disturbed character of the crust in a 20 to 30-km-wide zone. The time sections also show the presence of strong bands of reflectors covering the entire crustal column in the first 65 km of the northwestern portion of the profile. These reflections predominantly dip northward creating a domal structure with the apex around 30 km northwest of the CIS. There are a very few reflections in the upper 2–2.5 s two-way time (TWT), but the reflectivity is good below 2.5 s TWT. The reflection Moho, taken as the depth to the deepest set of reflections, varies in depth from 41 to 46 km and is imaged sporadically across the profile with the largest amplitude occurring in the northwest. We interpret these data as recording the presence of a mid-Proterozoic collision between two micro-continents, with the Satpura Mobile Belt being thrust over the Bastar craton.  相似文献   

Application of Spectral Decomposition to Detection of Fracture-Cavity Carbonate Reservoir Beds in the Tahe Oilfield, Tarim Basin, NW China     

LIU Xiaoping  YANG Xiaolan  ZHANG Yazhong  HAN Long 《《地质学报》英文版》2008,82(3)

Ordovician fracture-cavity carbonate reservoir beds are the major type of producing formations in the Tahe oilfieid, Tarim Basin. The seismic responses of these beds clearly changes depending on the different distance of the fracture-cavity reservoir bed from the top of the section. The seismic reflection becomes weak or is absent when the fracture-cavity reservoir beds are less than 20 ms below the top Ordovician. The effect on top Ordovician reflection became weaker with deeper burial of fracture-cavity reservoir beds but the developed deep fracture-cavity reservoir beds caused stronger reflection in the interior of the Ordovician. This interior reflection can be divided into strong long-axis, irregular and bead string reflections, and was present 80 ms below the top Ordovician. Aimed at understanding reflection characteristics, the spectral decomposition technique, which uses frequency to "tune-in" bed thickness, was used to predict Ordovician fracture-cavity carbonate formations in the Tahe oilfield. Through finely adjusting the processing parameters of spectral decomposition, it was found that the slice at 30 Hz of the tuned data cube can best represent reservoir bed development. Two large N-S-trending strong reflection belts in the mid-western part of the study area along wells TK440- TK427-TK417B and in the eastern part along wells TK404-TK409 were observed distinctly on the 30 Hz slice and 4-D time-frequency data cube carving. A small N-S trending reflection belt in the southern part along wells T403-TK446B was also clearly identified. The predicted reservoir bed development area coincides with the fracture-cavities connection area confirmed by drilling pressure testing results. Deep karst cavities occur basically in three reservoir bed-development belts identified by the Ordovician interior strong reflection. Spectral decomposition proved to be a useful technique in identifying fracture-cavity reservoir beds.  相似文献   

气体地球化学方法在震后趋势判断中的应用   总被引：3，自引：0，他引：3  

谷元珠  林元武  张培仁 《地震》2001,21(2):101-104

初步讨论了气体地球化学方法在顺义4.5级地震震后趋势判断中的应用。研究表明，震中区土壤Hg释放量快速衰减；延庆龙庆峡水库翻花冒气异常释放的主要气体CH4来源于生物成因，而非地震前兆异常。据此认为顺义地震之后，首都圈构造活动水平没有增强的趋势，并于1996年12月27日提出未来15天内首都圈发生Ms≥5.0地震的可能性很小的预测意见。  相似文献   

卫星通信技术在地震现场中的应用   总被引：7，自引：0，他引：7  

李大辉  吴耘  任镇  韩磊  唐迎欣  王玉民 《地震》2001,21(4):43-46

介绍了卫星通信技术在地震现场中的应用实例，叙述了最新研制并集成“地震现场指挥部图像信息传输系统”的有关技术特点、技术优势、系统功能、系统结构、工作流程、技术指标及用户接口等内容，并对系统的应用前景和应用领域作了分析。  相似文献   

声子波及其在地震波资料分解中的应用   总被引：3，自引：0，他引：3       下载免费PDF全文

陈凌  吴如山  陈镲  王伟君 《地球物理学报》2001,44(3):369-378

声子波是由声波波动方程的解构成的一种物理子波,如果不考虑吸收和散射,声子波的传播是相当简单的;相反地,数学子波的传播即使在均匀介质中也是极其复杂的.作为波动方程的解,声子波比一般的数学子波更能有效地应用于复杂声波和地震波的分解和分析.本文从Kaiser的声子波理论出发,给出了通过分别引入点源波形的复时间函数和点源虚时间坐标来构成声子波的两种解释,并对点源模型的合成地震图和实际复杂模型的地震波资料进行了时-空域的声子波变换,说明了声子波应用于地震波资料分解的有效性.  相似文献