摘要: |
利用地震走时数据,采用联合反演方法获取了江苏地区的一维P波速度模型。与仅采用初至波走时的传统天然地震走时获取方法相比,该方法充分利用了大量存在的续至波参与反演,能有效改进中下地壳的反演能力。针对地震震相目录中常存在震相标识错误的问题,采用的自动判别筛选震相方法能最大限度提高数据走时的精度,可以对不同震相进行有效区分。与其他常用一维速度模型相比,本文反演的模型对Pg、Pn震相走时拟合效果最佳,残差最小。当所用走时数据拥有较高定位精度时,该反演方法能为研究区三维速度结构成像和地震定位提供较可靠的一维速度模型。 |
关键词: 联合反演 一维速度结构 江苏地区 续至波 |
DOI: |
分类号:P315 |
基金项目:江苏省地震局青年基金项目(16028)、江苏省地震局局长基金项目(201501JY)共同资助 |
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The Study of 1D Velocity Model Based on Multi-phase Joint Inversion in Jiangsu Province |
Li Xibing, Zhao Qiguang, Zhu Feng, Hong Haichun, Wang Hengzhi
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Jiangsu Earthquake Agency, Nanjing 210014, China
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Abstract: |
A joint inversion method is adopted to invert 1D P-wave velocity of Jiangsu Province from bulletin data. Different from traditional method only for the first arrival,we use the first and secondary arrivals simultaneously to invert 1D velocity model. The secondary arrival for inversion can constrain velocity resolution of middle-lower crust. In order to constrain the bulletin data,a procedure is constructed to discriminate the different phases,such as Pn and Pg phase. It shows that this procedure can operate effectively in joint inversion. Synthetic travel-times are calculated with several 1D P-wave velocity models for bulletin data. The result presents that our inversion model performs the least RMS residuals. When the bulletin data have high location ability,the result of our inversion can be used as the initial model for 3D seismic tomography and routine earthquake determination in Jiangsu Province. |
Key words: Joint inversion 1D velocity model Jiangsu Province Secondary arrival |