The S wave velocity structure of the earth below Eastern Southeast Asia has been investigated by analyzing the seismogram from surface wave to multiple depth waves in the time domain and three Cartesian components sim...The S wave velocity structure of the earth below Eastern Southeast Asia has been investigated by analyzing the seismogram from surface wave to multiple depth waves in the time domain and three Cartesian components simultaneously.The wave passes across the front area of subduction zone between the Philippine plate and the Asian plate.The main data are waveform comparisons,instead of the arrival times.The synthetic seismogram is calculated using the GEMINI method.The synthetic seismogram constructed by PREMAN global earth model deviates greatly from the measured one.To solve this problem,corrections are needed for the β speed structure.Corrections cover the gradient change of β_h,which turns from negative to positive in upper mantle layers as in the PREMAN,change of earth crust depth and change of zero order coefficients of β velocity function in all earth mantle layers.So,the fitting is obtained,as well as the arrival time or the waveform of Love and Rayleigh surface waves,the S wave and the repetitive depth waves ScS_2 and ScS_3.This result reveals that the Southeast Asia,being stretched due to tectonic release,has a mantle in some parts with negative anomaly of S wave velocity and vertical anisotropy in all earth mantle layers.展开更多
Based on the network monitoring data and field investigations,the basic characteristics of the M S4.9 earthquake at the juncture of Gaoyou and Baoying in Jiangsu Province on July20,2012 have been introduced,and the fo...Based on the network monitoring data and field investigations,the basic characteristics of the M S4.9 earthquake at the juncture of Gaoyou and Baoying in Jiangsu Province on July20,2012 have been introduced,and the focal mechanism solutions have also been obtained.According to the regional tectonic features and site macroscopic survey,the occurrence of the earthquake was probably related to the Yangchacang-Sangshutou fault.Based on site survey data,both the evaluation criterion of seismic intensity of this region and the seismic intensity maps have been proposed.According to the damage characteristics of brick-concrete structure and brick-wood structure,the main reasons of serious damage for buildings are poor foundation conditions,low seismic bearing capacity,poor quality of construction and disrepair.Considering the differences of earthquake damage in the different regions,advice on accelerating the new rural construction,improving the resistance against earthquake disasters of rural residential areas and strengthening the seismogenic research on strong and moderate size earthquake is proposed,which will be possibly helpful for earthquake damage survey,prediction and prevention.展开更多
基金This research is funded by the DanaHibah Penelitian Dasar of DIKTI (Grant Fund of the Basic Research from Higher Education Agency) with grant number 019/SP3/PP/DP2M/Ⅱ/2006
文摘The S wave velocity structure of the earth below Eastern Southeast Asia has been investigated by analyzing the seismogram from surface wave to multiple depth waves in the time domain and three Cartesian components simultaneously.The wave passes across the front area of subduction zone between the Philippine plate and the Asian plate.The main data are waveform comparisons,instead of the arrival times.The synthetic seismogram is calculated using the GEMINI method.The synthetic seismogram constructed by PREMAN global earth model deviates greatly from the measured one.To solve this problem,corrections are needed for the β speed structure.Corrections cover the gradient change of β_h,which turns from negative to positive in upper mantle layers as in the PREMAN,change of earth crust depth and change of zero order coefficients of β velocity function in all earth mantle layers.So,the fitting is obtained,as well as the arrival time or the waveform of Love and Rayleigh surface waves,the S wave and the repetitive depth waves ScS_2 and ScS_3.This result reveals that the Southeast Asia,being stretched due to tectonic release,has a mantle in some parts with negative anomaly of S wave velocity and vertical anisotropy in all earth mantle layers.
基金Supported by Key Project of Suzhou Municipal Government,China(No.2009-191)Key Project of Xuzhou Municipal Government,China(T(2009)009)
文摘Based on the network monitoring data and field investigations,the basic characteristics of the M S4.9 earthquake at the juncture of Gaoyou and Baoying in Jiangsu Province on July20,2012 have been introduced,and the focal mechanism solutions have also been obtained.According to the regional tectonic features and site macroscopic survey,the occurrence of the earthquake was probably related to the Yangchacang-Sangshutou fault.Based on site survey data,both the evaluation criterion of seismic intensity of this region and the seismic intensity maps have been proposed.According to the damage characteristics of brick-concrete structure and brick-wood structure,the main reasons of serious damage for buildings are poor foundation conditions,low seismic bearing capacity,poor quality of construction and disrepair.Considering the differences of earthquake damage in the different regions,advice on accelerating the new rural construction,improving the resistance against earthquake disasters of rural residential areas and strengthening the seismogenic research on strong and moderate size earthquake is proposed,which will be possibly helpful for earthquake damage survey,prediction and prevention.
