| 摘要: |
| 2014年11月22日康定MS6.3、MS5.8地震发生在鲜水河断裂带南段的色拉哈段和折多塘段上。主、余震的时空分布，地震蠕变释放曲线以及震后30天地震日频度均显示，2014年康定地震的地震破裂传播和地震能量释放存在鲜明的时空分段性。对比鲜水河断裂带上1960年以来中强地震的构造位置、地震蠕变曲线、围岩特征等可知，鲜水河断裂带上大部分中强地震序列类型均为主余型或是孤立型，只有发生在鲜水河断裂带南端贡嘎山岩体(折多山花岗岩)周边的1972年康定地震(塔公地震)和2014年康定地震为震群型地震。鲜水河断裂带上震群型地震很可能与强硬的新生代贡嘎山岩体有关。由于岩体的阻挡，震级较小的地震能量较小，不足以使地震破裂在岩体内部传播，导致地震能量转而在岩体周围的相对较软弱的岩层内储存、爆发，从而产生震群型地震序列特征。 |
| 关键词: 2014年康定地震 1972年康定地震 震群型 贡嘎山岩体 |
| DOI： |
| 分类号: |
| 基金项目:中国地震局地震科技星火计划项目(XH15049Y)、国家自然科学基金(41404043,41004037)共同资助 |
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| Discussion on seismogenic structures of the 2014 Kangding MS6.3，MS5.8 earthquakes with multiple mainshocks |
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Liao Lin1) Yao Qi2) Liu Jie2) Zhang Wei3)
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1)China University of Petroleum，Beijing 102249，China；2)China Earthquake Networks Center，Beijing 100045，China；3)China Aero Geophysical Survey & Remote Sensing Center for Land and Resources，Beijing 100083，China
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| Abstract: |
| The Kangding MS6.3，MS5.8 earthquakes with two mainshocks occurred in the southern segments of Selaha and Zheduotang of the Xianshuihe fault. The spatial and temporal distribution of mainshocks and aftershocks，the energy release process，and the daily earthquake frequency in 30 days after the first mainshock showed that they were spatial-time segmentations. The seismogenic structures，energy release and surrounding rocks of moderate-strong earthquakes in the Xianshuihe fault since 1962 reveal that most earthquakes in the Xianshuihe fault are of isolated earthquake types and mainshock-aftershock types. Only the 1972 Kangding(Tagong)earthquake and 2014 Kangding earthquake are of the multiple mainshock type，both occurring around the huge Cenozoic granitic mass，called Gongga mountain mass(also called “Zheduoshan granitic mass”)，in the southern of the Xianshuihe fault. The multiple mainshocks of these earthquakes may be caused by the resistance of tough Cenozoic Gongga mass. The moderate earthquakes could not continue propagation in strong mass，and the accumulative energy in sandstone and altered sandstone nearby resulted in the next mainshocks. |
| Key words: 2014 Kangding earthquake 1972 Kangding earthquake Multiple mainshock type Gongga mountain granitic mass |
