Analysis of GEONET observations covering the entire territory of Japan shows that the great Tohoku-oki earthquake that occurred on March 11, 2011 off the east coast of Honshu in Japan caused an eastward movement of th...Analysis of GEONET observations covering the entire territory of Japan shows that the great Tohoku-oki earthquake that occurred on March 11, 2011 off the east coast of Honshu in Japan caused an eastward movement of the northern part of the island by as much as 5.3 m. The GPS data from TEONET in China were used to derive far-field coseismic displacements and to assess the impact of the Tohoku-oki earthquake on crustal deformation in eastern China. The results reveal that the coseismic horizontal displacements induced by the earthquake are the level of millimeters to centimeters in North and Northeast China, with a maximum of 35 mm. Strain analysis also indicates that the earthquake resulted in an increase in the tensile strain on the north-northeast trending faults in North and Northeast China. The tensile strain imposed on the Yilan-Yitong and Dunhua-Mishan faults is more significant than that imposed on the faults in North China; the maximum normal strain reaches about 40 nano-strain. Considering that the static Coulomb stress loaded on the faults is limited, its effect on the regional seismic activity may not be significant.展开更多
为全面准确地描述地震相特征,在地震相分析中引入了时频分析技术,如短时窗傅里叶变换、Cabor 变换、小波变换等。之后发展起来的 S 变换时频分析方法综合了短时窗傅里叶变换和小波变换的优点,具有线性化、无损可逆性以及高时频分辨率等...为全面准确地描述地震相特征,在地震相分析中引入了时频分析技术,如短时窗傅里叶变换、Cabor 变换、小波变换等。之后发展起来的 S 变换时频分析方法综合了短时窗傅里叶变换和小波变换的优点,具有线性化、无损可逆性以及高时频分辨率等特性。阐述了 S 变换的基本理论,并利用 S 变换对理想的地震序列模型以及实际地震资料进行了地震相分析。通过对地震相特征的连续性以及振幅和频率变化特征的分析发现,对于规模较小的地震相体,在时间剖面上很难识别其层序内的地震相特征(特别是频率)随旅行时的变化情况,但在 S 变换的时频域内可以被清楚地体现出来。因此,在进行沉积环境识别时,可以利用 S 变换来提供有效地震信息。展开更多
基金supported by the State Key Laboratory of Earthquake Dynamics (LED2009A02)the National Key Infrastructure Project "Tectonic and Environmental Observation Network in China"
文摘Analysis of GEONET observations covering the entire territory of Japan shows that the great Tohoku-oki earthquake that occurred on March 11, 2011 off the east coast of Honshu in Japan caused an eastward movement of the northern part of the island by as much as 5.3 m. The GPS data from TEONET in China were used to derive far-field coseismic displacements and to assess the impact of the Tohoku-oki earthquake on crustal deformation in eastern China. The results reveal that the coseismic horizontal displacements induced by the earthquake are the level of millimeters to centimeters in North and Northeast China, with a maximum of 35 mm. Strain analysis also indicates that the earthquake resulted in an increase in the tensile strain on the north-northeast trending faults in North and Northeast China. The tensile strain imposed on the Yilan-Yitong and Dunhua-Mishan faults is more significant than that imposed on the faults in North China; the maximum normal strain reaches about 40 nano-strain. Considering that the static Coulomb stress loaded on the faults is limited, its effect on the regional seismic activity may not be significant.
文摘为全面准确地描述地震相特征,在地震相分析中引入了时频分析技术,如短时窗傅里叶变换、Cabor 变换、小波变换等。之后发展起来的 S 变换时频分析方法综合了短时窗傅里叶变换和小波变换的优点,具有线性化、无损可逆性以及高时频分辨率等特性。阐述了 S 变换的基本理论,并利用 S 变换对理想的地震序列模型以及实际地震资料进行了地震相分析。通过对地震相特征的连续性以及振幅和频率变化特征的分析发现,对于规模较小的地震相体,在时间剖面上很难识别其层序内的地震相特征(特别是频率)随旅行时的变化情况,但在 S 变换的时频域内可以被清楚地体现出来。因此,在进行沉积环境识别时,可以利用 S 变换来提供有效地震信息。
