| 摘要: |
| 通过联合使用固定台站和流动台站资料，对2010年5月～2011年7月发生在云南地区的7127个地震进行重新定位。考虑到速度模型对定位结果的影响，用VELEST方法获得云南地区走时残差均方根最小的一维P波速度模型，基于反演模型用双差法对地震进行重新定位，得到5836个地震的定位结果。结果表明，云南地区发震层主要位于中上地壳，且滇西地区震源深度相对较深。用精定位后的地震目录计算云南地区b值，从b值空间分布特征可以看出，b值随深度逐渐减少，且在9～10km深度时，b值变化最为明显，可能表明云南地区中强震孕震层主要位于9km以下；同时，盈江5.8级地震序列b值的三维空间分布显示，主震发生在高低b值的过渡带。 |
| 关键词: b值 双差定位 中上地壳 一维速度模型 |
| DOI： |
| 分类号: |
| 基金项目:科研院所基本科研业务专项(ZDJ2013-12)和国家自然科学基金项目(41304037)资助 |
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| Research on earthquake relocation and bvalue in the Yunnan area |
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Zhang Guangwei
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Key Laboratory of Crustal Dynamics，Institute of Crustal Dynamics，CEA，Beijing 100085，China
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| Abstract: |
| We relocated 7172 earthquakes occurring in the Yunnan area from May,2010 to July,2011 by jointly using the permanent and temporary station records data. Considering the impact of velocity model，we first obtained a 1-D mininum P velocity model with the VELEST method. And then we got 5836 epicenter results by applying the double-difference method，and the resluts show that the seismogenic layer is basically located in the upper and middle crust，and the focal depth is more deeper in western Yunnan. We caculate the b-value of the Yunnan area using the relocated earthquake catalogs，and some new recognitions were achieved：the b-value was gradually reduced with depth，particularly at the depth of 9～10km；and the b-value 3-D distribution of the Yingjiang MS5.8 earthquake sequences showed that the main shock was in the transition zone with high and low b-value. |
| Key words: bvalue Doubledifference method Upper and middle crust 1D velocity model |
