| 芦山地震崩滑灾害空间分布及相关问题探讨 |
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| 引用本文： | 周庆,江亚风,吴果,陈国光.芦山地震崩滑灾害空间分布及相关问题探讨[J].地震地质,2014,36(2):344-357. |
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| 作者姓名： | 周庆 江亚风 吴果 陈国光 |
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| 作者单位： | 中国地震局地质研究所, 活动构造与火山重点实验室, 北京 100029 |
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| 摘 要： | 由于逆断层作用，2013年芦山MS 7.0地震诱发的崩滑地质灾害分布表现出了明显的上盘效应与方向效应。在震后应急科考中未发现发震断层的地表破裂带，然而灾区大量出现的地震诱发滑坡、崩塌，加之密集的余震分布、地震烈度调查结果等，提供了确定芦山地震宏观震中、地震动错动方向以及研究地震发震构造等的诸多线索。 统计结果表明，芦山地震诱发的滑坡、崩塌具有明显的优势滑动方向（135°～144°），该方向揭示了地震断层的错动方向，与震源机制解反映的一致，大体垂直于发震断层的走向；从地震诱发崩塌、滑坡灾害点的分布与密度判断，宏观震中位于宝盛乡北，在仪器记录震中东北约3.6km处；从余震群分布、地震诱发滑坡分布特点及地震等烈度线等，结合以往强震如汶川地震等的调查经验，推测当震级足够大时，发震断层地表破裂带可能通过地质灾害、余震密集区东侧的边缘地带，总体平行于双石-大川断裂。另外，通过分析地层岩性与崩滑地形条件之间的关联性，发现崩滑灾害在某些地层岩性中易发，灾害点呈线性排列的原因是不同地层岩性之间抗风化能力的差异性，造成在地层分界线上形成线性陡崖或高坡度地带，使之在强震作用下容易发生崩塌、滑坡。
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| 关 键 词： | 芦山地震 崩塌滑坡 滑动方向 宏观震中 发震断层 |
| 收稿时间： | 2013-07-25 |
| 修稿时间： | 2014-04-16 |
DISTRIBUTION OF COSEISMIC LANDSLIDES IN LUSHAN EARTHQUAKE AND DISCUSSION ON RELATED PROBLEMS |
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| ZHOU Qing,JIANG Ya-feng,WU Guo,CHEN Guo-guang.DISTRIBUTION OF COSEISMIC LANDSLIDES IN LUSHAN EARTHQUAKE AND DISCUSSION ON RELATED PROBLEMS[J].Seismology and Geology,2014,36(2):344-357. |
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| Authors: | ZHOU Qing JIANG Ya-feng WU Guo CHEN Guo-guang |
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| Affiliation: | Key Laboratory of Active Tectonics and Volcano, Institute of Geology, China Earthquake Administration, Beijing 100029, China |
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| Abstract: | Geological disaster distribution induced by the 2013 MS7.0 Lushan earthquake shows clear hanging wall effect and direction effect under reverse fault motion. No surface rupture was found in the post-earthquake emergency field surveys. We developed a detailed geo-spatial database of 2230 rock falls and landslides based on post-earthquake field surveys and examination of high-resolution aerial photographs across the disaster area. Landslides triggered by earthquake, dense aftershocks and isoseismal map provide clues to study the unrevealed causative fault.Statistics show that rock falls and landslides have a dominant slide direction of southeast(135°～144°), which is perpendicular to the strike of the causative fault. This result is consistent with the focal mechanisms. From distribution and density of seismic disasters, the macroscopic epicenter was relocated on the northern edge of Baosheng Town, ～3.6 km from the instrumental location. The probable surface rupture may appear on the edge of dense region of coseismic landslides and aftershocks, paralleling to the Shuangshi-Dachuan Fault. Because of difference in weatherability of rocks, linear cliffs or high-angle topography are formed between different strata or igneous rocks, and these regions are susceptible to rock falls and landslides under the action of strong earthquake. |
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| Keywords: | Lushan earthquake rock falls and landslides slide direction macroscopic epicenter causative fault |
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