On the basis of the Xining active urban fault survey, we studied the relationship between the active urban fault and fold deformation. The result of this research shows that the Huangshuihe fault and the NW-striking f...On the basis of the Xining active urban fault survey, we studied the relationship between the active urban fault and fold deformation. The result of this research shows that the Huangshuihe fault and the NW-striking fault on the northern bank of the Huangshulbe River are tensional faults on top of an anticline, the Nanchuanhe fault is a transverse tear fault resulting from differential folding on two sides of the fault, the east bank of the Beichuanhe River fault is a compressional fault developed on the core or climb of a syncline. By balance profile analysis of fold deformation and inversion of gravity anomaly data, we obtained the depth of the detachment plane and established the seismotectonic model of the ）fining urban area. Based on the seismotectonic model, we analyzed the earthquake potential of the active urban fault.展开更多
A compilation of databases from Cameroon and neighbouring countries,including seismicity,stress tensor distribution,gravity,magnetic,topography,lithosphere structure and geological data,is used to define its seismotec...A compilation of databases from Cameroon and neighbouring countries,including seismicity,stress tensor distribution,gravity,magnetic,topography,lithosphere structure and geological data,is used to define its seismotectonic zonation.Based on the quality and quantity of available data,a seismotectonic map was drawn up through the characterization of subunits of concentrations of earthquake foci and,large neotectonic and structural domains.To prepare this map,a homogeneous earthquake catalogue was compiled from the literature and international data centers dated from 1852 up to 2023.Another point of study was to establish links between seismicity and deformation zones.Many faults and/or structures were identified as possibly active,although some of them are not always associated with seismicity.A seismotectonic model for Cameroon was then built from a classification of faults,neotectonic and seismogenic regions.This structured and highly data-driven approach has been developed specifically for the definition of source zones where seismicity is not well known.The results of the seismotectonic analysis allowed characterizing seventeen seismotectonic source zones in Cameroon.Five source zones are defined in the Mount Cameroon region which is the greatest seismicity activity in the study area.The crustal thickness map of Cameroon revealed a thinned transitional zone interspersed between the thickened Congo Shield and thin Pan-African belt favourable for the development of megastructures such as Central Cameroon shear zone and Kribi-Campo shear zone.This region represents the second highest seismicity zone and contains five source zones.展开更多
In seismic hazard analysis of nuclear power plant of China there is a need to identify both seismogenic structures and seismotectonic zones. In past practice,the identification of the seismogenic structures was often ...In seismic hazard analysis of nuclear power plant of China there is a need to identify both seismogenic structures and seismotectonic zones. In past practice,the identification of the seismogenic structures was often based on the surface active faults and characterization of linear seismic source. In a situation which shows quite strong non-random seismic activity and lacks surface active faults,it is difficult to evaluate the seismic hazard reasonably. Taking seismogenic structures in the Dayao-Yao'an area as a case study in this paper,we discuss the need and the possibility to apply the planar seismogenic structure to the seismotectonic method. We suggest that the planar seismogenic structure should be considered when applying the seismotectonic method to the seismic risk assessment of nuclear engineering in future.展开更多
基金This project was sponsored by National Development and Reform Commission (NDRC) on studies of experimental exploration of active fault in urban area(20041138)
文摘On the basis of the Xining active urban fault survey, we studied the relationship between the active urban fault and fold deformation. The result of this research shows that the Huangshuihe fault and the NW-striking fault on the northern bank of the Huangshulbe River are tensional faults on top of an anticline, the Nanchuanhe fault is a transverse tear fault resulting from differential folding on two sides of the fault, the east bank of the Beichuanhe River fault is a compressional fault developed on the core or climb of a syncline. By balance profile analysis of fold deformation and inversion of gravity anomaly data, we obtained the depth of the detachment plane and established the seismotectonic model of the ）fining urban area. Based on the seismotectonic model, we analyzed the earthquake potential of the active urban fault.
文摘A compilation of databases from Cameroon and neighbouring countries,including seismicity,stress tensor distribution,gravity,magnetic,topography,lithosphere structure and geological data,is used to define its seismotectonic zonation.Based on the quality and quantity of available data,a seismotectonic map was drawn up through the characterization of subunits of concentrations of earthquake foci and,large neotectonic and structural domains.To prepare this map,a homogeneous earthquake catalogue was compiled from the literature and international data centers dated from 1852 up to 2023.Another point of study was to establish links between seismicity and deformation zones.Many faults and/or structures were identified as possibly active,although some of them are not always associated with seismicity.A seismotectonic model for Cameroon was then built from a classification of faults,neotectonic and seismogenic regions.This structured and highly data-driven approach has been developed specifically for the definition of source zones where seismicity is not well known.The results of the seismotectonic analysis allowed characterizing seventeen seismotectonic source zones in Cameroon.Five source zones are defined in the Mount Cameroon region which is the greatest seismicity activity in the study area.The crustal thickness map of Cameroon revealed a thinned transitional zone interspersed between the thickened Congo Shield and thin Pan-African belt favourable for the development of megastructures such as Central Cameroon shear zone and Kribi-Campo shear zone.This region represents the second highest seismicity zone and contains five source zones.
基金jointly supported by the Special Fund for Major Large-scale Advanced PWR Nuclear Power Plant(2011ZX06002)the Special Fund for Basic Research and Operating Expenses of Institute of Geophysics,China Earthquake Administration(DQJB11C08)
文摘In seismic hazard analysis of nuclear power plant of China there is a need to identify both seismogenic structures and seismotectonic zones. In past practice,the identification of the seismogenic structures was often based on the surface active faults and characterization of linear seismic source. In a situation which shows quite strong non-random seismic activity and lacks surface active faults,it is difficult to evaluate the seismic hazard reasonably. Taking seismogenic structures in the Dayao-Yao'an area as a case study in this paper,we discuss the need and the possibility to apply the planar seismogenic structure to the seismotectonic method. We suggest that the planar seismogenic structure should be considered when applying the seismotectonic method to the seismic risk assessment of nuclear engineering in future.
