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51.
山东Ⅱ、Ⅲ类场地地震动峰值加速度放大效应分析 总被引:1,自引:0,他引:1
利用山东地区实测的Ⅱ类场地358个钻孔和Ⅲ类场地140个钻孔的地震动峰值加速度,计算了各个钻孔不同超越概率的土层地震动峰值加速度的放大系数ks,结果表明:(1)同类场地土层放大系数ks值总体符合正态分布,既有相对集中性,也有离散性;(2)随着基岩面输入地震动强度的增大,ks值降低,且Ⅲ类场地ks值降低较Ⅱ类的更为明显;(3)Ⅱ类场地随着基岩输入面埋深的增加,ks值呈增加趋势,约达20m深后基本趋于稳定,而Ⅲ类场地基岩输入面埋深的增加对ks值的影响不甚显著;(4)Ⅱ类场地50年超越概率10%的平均ks值(1.47)略高于《中国地震动参数区划图》使用的全国平均ks值.本文尝试讨论了山东地区Ⅱ、Ⅲ类场地不同强度基岩峰值加速度输入的ks调整值. 相似文献
52.
研究了我国青藏块体地区每一地震活跃幕里地震活动的主体地区、地震活动强度和地震活动持续时间,认为2008年四川汶川8.0级地震的发生可能意味着我国青藏块体自1995年或1997年开始的地震活跃幕已经进入后期,同时也意味着这一地区自1920年以来更长时间尺度里的地震活动期也进入了收尾阶段.未来几年青藏块体地震活动水平为7级... 相似文献
53.
平武地震台数字地震仪记录近震震级及定位偏差 总被引:2,自引:0,他引:2
以《四川省地震台网地震目录》作为地震定位参考标准,对平武地震台数字地震仪记录的近震,尤其是汶川"5·12"地震序列定位参数进行了对比。结果表明,平武单台数字地震仪记录得到的测定结果与《四川省地震台网地震目录》间存在一定程度的差异。这里给出了台站可以简单应用的偏差评估值和处理方法。 相似文献
54.
三维全景是一种基于静态图像的真实场景虚拟现实技术,首先简要叙述该技术的主要原理和技术路线,基于此建立了可以在网络上发布和浏览的三维全景虚拟地震台站系统,该技术丰富了防震减灾宣传工作的手段和内容. 相似文献
55.
一种基于Google Maps的地震信息节点显示地震震中的模式 总被引:2,自引:0,他引:2
Google Maps API是Google公司提供的免费WebGis电子地图应用服务.本文根据地震信息节点的网络状况,以Google Maps为开发基础,以地震信息通道为载体,综合运用多种技术手段.建立面向信息节点服务的地震震中地图发布中心,为市、县地震机构提供一个实时地震信息展示平台.一方面提高了信息节点的地震数据... 相似文献
56.
57.
The Campos, Santos and Pelotas basins have been investigated in terms of 2D seismo-stratigraphy and subsidence. The processes controlling accommodation space (e.g. eustacy, subsidence, sediment input) and the evolution of the three basins are discussed. Depositional seismic sequences in the syn-rift Barremian to the drift Holocene basin fill have been identified. In addition, the subsidence/uplift history has been numerically modeled including (i) sediment flux, (ii) sedimentary basin framework, (iii) relation to plate-tectonic reconfigurations, and (iv) mechanism of crustal extension. Although the initial rift development of the three basins is very similar, basin architecture, sedimentary infill and distribution differ considerably during the syn-rift sag to the drift basin stages. After widespread late Aptian–early Albian salt and carbonate deposition, shelf retrogradation dominated in the Campos Basin, whereas shelf progradation occurred in the Santos Basin. In the Tertiary, these basin fill styles were reversed: since the Paleogene, shelf progradation in the Campos Basin contrasts with overall retrogradation in the Santos Basin. In contrast, long-term Cretaceous–Paleogene shelf retrogradation and intense Neogene progradation characterize the Pelotas Basin. Its specific basin fill and architecture mainly resulted from the absence of salt deposition and deformation. These temporally and spatially varying successions were controlled by specific long-term subsidence/uplift trends. Onshore and offshore tectonism in the Campos and Santos basins affected the sediment flux history, distribution of the main depocenters and occurrence of hydrocarbon stratigraphic–structural traps. This is highlighted by the exhumation and erosion of the Serra do Mar, Serra da Mantiqueira and Ponta Grossa Arch in the hinterland, as well as salt tectonics in the offshore domain. The Pelotas Basin was less affected by changes in structural regimes until the Eocene, when the Andean orogeny caused uplift of the source areas. Flexural loading largely controlled its development and potential hydrocarbon traps are mainly stratigraphic. 相似文献
58.
Himalayan orogenic belt is the highest and largest continental collision and subduction zone on the Earth. The Himalayan orogenic belt has produced frequent large earthquakes and caused several geohazards due to landslides and housing collapse, having an impact on the safety of life and property along a length of over 2500 km. Here we took three earthquake clusters as examples, which occurred at Nepal Himalaya, eastern Himalayan syntaxis and western Himalayan syntaxis, respectively. Here we calculated the earthquake locations and fault plane solutions based on the waveform data recorded by seismic stations deployed in source areas by the Institute of Tibetan Plateau Research, Chinese Academy of Sciences. We found that at the Nepal Himalayan, the Main Himalayan Thrust is the major tectonic structure for large earthquakes to occur. At the eastern Himalayan syntaxis, most earthquakes are of the reverse or strike-slip faulting. The major tectonic feature is the combination of the NE-dipping thrust with the southeastern escape of the Tibetan plateau. At the western Himalayan syntaxis, intermediate-depth earthquakes are active. These observations reveal the geometry of the deep subduction of the continental plate with steep dipping angle. 相似文献
59.
”Deep well, wide band, multi-component comprehensive observation” is the development direction of seismic observation. In order to promote the application and development of underground integrated observation system, key technologies, such as high temperature resistance sensor, interference isolation of sensor unit and miniaturization of instrument, need to be developed. Optic fiber sensors have the advantages of small size, passive nature, resistance to electromagnetic interference, being easy to long distance transmission and multi-parametric network observation, which are expected to provide new technology for the comprehensive observation of multi-parameter earthquakes in deep wells. This paper proposed a comprehensive observation technique of seismic wave, crustal deformation and temperature. An integrated borehole seismic sensor based on fiber Bragg grating resonators was designed for measuring three-component earthquake, three-component crustal deformation and temperature signal. A new technique for simultaneous measurement of multi-parameters of temperature and strain of fiber based on effective cavity length was presented. The technique of high precision optical fiber signal demodulation based on single side band sweep laser and the design of multi-parameter integrated optical fiber probe were introduced. The resolution of strain and temperature measurement of the fiber multi-parameter sensor system reached 4.7 10-10 and 6×10-5 , respectively. A comprehensive multi-parameter earthquake observation experiment was carried out at the seismic station. The results show that the integrated optical fiber multi-parameter seismic observation system can simultaneously record the earth tide signal, seismic wave signal and environmental temperature disturbance, and has good anti-environmental interference ability and long-term stability, which is expected to provide a new technique for crustal deformation observation. 相似文献
60.
地震是群灾之首,地震灾害不可抗拒,只能防御,建设工程进行合理的抗震设防是震灾预防的关键环节,规范各类建设工程抗震设防管理是社会抵御地震灾害最为有效的途径.对南华县抗震设防管理现状和存在的问题进行深入分析后,提出了进一步规范抗震设防管理的对策意见. 相似文献