Using the data of P-wave network and Zhejiang and travel time recorded at the Shanxi-reservoir seismological Fujian local networks, we implemented a simultaneous inversion of earthquake relocation and velocity struct...Using the data of P-wave network and Zhejiang and travel time recorded at the Shanxi-reservoir seismological Fujian local networks, we implemented a simultaneous inversion of earthquake relocation and velocity structure and determined the new locations of earthquakes in the Shanxi-reservoir. The results show that: (1) the overall epicenter distribution is NW directed, and the Shanxi reservoir induced seismicity has a close relationship to the Shuangxi-Jiaoxiyang fault; (2) the focal depth of the Shanxi reservoir induced seismicity is 5.4km in average, less than the average focal depth in the South China earthquake zone; (3) the focal depth is shallower on the reservoir shore and deeper in the reservoir inundation area. At the beginning of the reservoir induced seismicity, the focal depth increased gradually. This may be due to the gradual penetration of water into a larger depth that induced deeper earthquakes; and (4) there is a low P-wave velocity anomaly in the study area, located at the intersection of multiple faults in the reservoir inundation area. The Shanxi reservoir induced seismicity mostly occurred in this lowvelocity anomaly zone. This may be related to water penetration.展开更多
The paper proposes the calibration theory and methods for the Shanghai seismic array and analyzes the calibration results. As a result, the calibration results for the seismic array based on 2 typical earthquakes have...The paper proposes the calibration theory and methods for the Shanghai seismic array and analyzes the calibration results. As a result, the calibration results for the seismic array based on 2 typical earthquakes have been drawn; the difference of calibration results between Hokkaido and Honshu region in Japan is investigated. And calibration results of different directions, different epicenter distances and different magnitudes are probed into. The result shows that the location of earthquakes on the Shanghai seismic array is greatly improved.展开更多
In this paper we discuss the seismogenic structures of the two earthquakes occurring in the Beibu Gulf waters,based on the investigation of geological structure,faults,geophysical fields,seismicity and earthquake foca...In this paper we discuss the seismogenic structures of the two earthquakes occurring in the Beibu Gulf waters,based on the investigation of geological structure,faults,geophysical fields,seismicity and earthquake focal mechanism.The results show that the NEE trending faults along the boundary of the Wushi depression are the dominating seismogenic structures,and the NW trending faults are the key factors of stress concentration.The results also show that high seismicity has a significant relationship with the late Cenozoic deposition center in the Beibu Gulf,and their NE-NEE trending boundary faults are important to the identification of seismogenic structures.The special arcuate fault segment or the intersection point of the NW trending faults and NE-NEE trending boundary faults is a possible location of future earthquakes.展开更多
A probabilistic seismic hazard analysis was performed to generate seismic hazard maps for Jamaica. The analysis was then conducted using a standard logic-tree approach that allowed systematically taking into account t...A probabilistic seismic hazard analysis was performed to generate seismic hazard maps for Jamaica. The analysis was then conducted using a standard logic-tree approach that allowed systematically taking into account the model-based (i.e., epistemic) uncertainty and its influence on the computed ground motion parameters. Hazard computations have been performed using a grid of sites with a space of 0.05 degrees. Two different computation methodologies have been adopted: the standard approach based on the definition of appropriate seismogenic sources and the zone-free approach, which overcomes the ambiguities related with the definition of the seismic sources solely reflecting the characteristics of the earthquake catalogue. A comprehensive and updated earthquake catalogue for Jamaica has been compiled for the years 1551-2010 and new empirical relationships amongst magnitudes Mze-Ms and Mw-mb have been developed for the region. Uniform hazard spectra and their uncertainty have been calculated for the horizontal component of ground motion for rock site conditions and five return periods (95, 475, 975, 2,475 and 4,975 years) and spectral accelerations for 34 structural periods ranging from 0 to 3 s, and 5% of critical damping. The spectral accelerations have been calculated to allow the definition of seismic hazard in Jamaica according to the International Building Code 2012. The disaggregation analysis for Kingston Metropolitan Area suggests that the magnitude-distance pair that contributes most to the hazard corresponds to events with M 7.8 and M 7.0 in the Enriquillo Plantain Garden Fault and the Jamaican Faults at a distance of 28 km and 18 km for short and long period structures respectively corresponding to 2,475 years return period. However, for long period structures, a substantial contribution is found for a M 8.2 at a distance of 198 km in the Oriente Fault Zone.展开更多
Seismic damage indices of structure are widely used to quantificationally analyze structural damage levels under earthquake action. In this paper, a five-storey building model and a seventeen-storey building model are...Seismic damage indices of structure are widely used to quantificationally analyze structural damage levels under earthquake action. In this paper, a five-storey building model and a seventeen-storey building model are established. According to seven typical indices and different earthquake-inputs, a structural damage prediction is performed, with the results showing serious uncertainty of structural damage prediction due to different indices. Understanding of this phenomenon aids the comprehension and application of the results of earthquake damage prediction.展开更多
基金supported by the National Key Technology R&D Program(2008BAC38B03-01-05)the Earthquake Scientific Research Project(200708020),China
文摘Using the data of P-wave network and Zhejiang and travel time recorded at the Shanxi-reservoir seismological Fujian local networks, we implemented a simultaneous inversion of earthquake relocation and velocity structure and determined the new locations of earthquakes in the Shanxi-reservoir. The results show that: (1) the overall epicenter distribution is NW directed, and the Shanxi reservoir induced seismicity has a close relationship to the Shuangxi-Jiaoxiyang fault; (2) the focal depth of the Shanxi reservoir induced seismicity is 5.4km in average, less than the average focal depth in the South China earthquake zone; (3) the focal depth is shallower on the reservoir shore and deeper in the reservoir inundation area. At the beginning of the reservoir induced seismicity, the focal depth increased gradually. This may be due to the gradual penetration of water into a larger depth that induced deeper earthquakes; and (4) there is a low P-wave velocity anomaly in the study area, located at the intersection of multiple faults in the reservoir inundation area. The Shanxi reservoir induced seismicity mostly occurred in this lowvelocity anomaly zone. This may be related to water penetration.
基金the State Key Marine Geological Laboratory of Tongji University,China
文摘The paper proposes the calibration theory and methods for the Shanghai seismic array and analyzes the calibration results. As a result, the calibration results for the seismic array based on 2 typical earthquakes have been drawn; the difference of calibration results between Hokkaido and Honshu region in Japan is investigated. And calibration results of different directions, different epicenter distances and different magnitudes are probed into. The result shows that the location of earthquakes on the Shanghai seismic array is greatly improved.
基金funded under the special project of earthquake study(200708003) under the National Key Technology R&D Program (2006BAC13B01),China
文摘In this paper we discuss the seismogenic structures of the two earthquakes occurring in the Beibu Gulf waters,based on the investigation of geological structure,faults,geophysical fields,seismicity and earthquake focal mechanism.The results show that the NEE trending faults along the boundary of the Wushi depression are the dominating seismogenic structures,and the NW trending faults are the key factors of stress concentration.The results also show that high seismicity has a significant relationship with the late Cenozoic deposition center in the Beibu Gulf,and their NE-NEE trending boundary faults are important to the identification of seismogenic structures.The special arcuate fault segment or the intersection point of the NW trending faults and NE-NEE trending boundary faults is a possible location of future earthquakes.
文摘A probabilistic seismic hazard analysis was performed to generate seismic hazard maps for Jamaica. The analysis was then conducted using a standard logic-tree approach that allowed systematically taking into account the model-based (i.e., epistemic) uncertainty and its influence on the computed ground motion parameters. Hazard computations have been performed using a grid of sites with a space of 0.05 degrees. Two different computation methodologies have been adopted: the standard approach based on the definition of appropriate seismogenic sources and the zone-free approach, which overcomes the ambiguities related with the definition of the seismic sources solely reflecting the characteristics of the earthquake catalogue. A comprehensive and updated earthquake catalogue for Jamaica has been compiled for the years 1551-2010 and new empirical relationships amongst magnitudes Mze-Ms and Mw-mb have been developed for the region. Uniform hazard spectra and their uncertainty have been calculated for the horizontal component of ground motion for rock site conditions and five return periods (95, 475, 975, 2,475 and 4,975 years) and spectral accelerations for 34 structural periods ranging from 0 to 3 s, and 5% of critical damping. The spectral accelerations have been calculated to allow the definition of seismic hazard in Jamaica according to the International Building Code 2012. The disaggregation analysis for Kingston Metropolitan Area suggests that the magnitude-distance pair that contributes most to the hazard corresponds to events with M 7.8 and M 7.0 in the Enriquillo Plantain Garden Fault and the Jamaican Faults at a distance of 28 km and 18 km for short and long period structures respectively corresponding to 2,475 years return period. However, for long period structures, a substantial contribution is found for a M 8.2 at a distance of 198 km in the Oriente Fault Zone.
基金sponsored by the National Basic Research Programof China (2006BAC13B02)the Science and Technology Special Program for Seismology, China Earthquake Administration (200708003)
文摘Seismic damage indices of structure are widely used to quantificationally analyze structural damage levels under earthquake action. In this paper, a five-storey building model and a seventeen-storey building model are established. According to seven typical indices and different earthquake-inputs, a structural damage prediction is performed, with the results showing serious uncertainty of structural damage prediction due to different indices. Understanding of this phenomenon aids the comprehension and application of the results of earthquake damage prediction.