| 芦山“4·20”7.0级地震同震位移场考证及地表变形模式初探 |
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| 引用本文： | 魏文薪,江在森,邹镇宇,杨永林,张龙,武艳强.芦山“4·20”7.0级地震同震位移场考证及地表变形模式初探[J].地震地质,2014,36(2):333-343. |
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| 作者姓名： | 魏文薪 江在森 邹镇宇 杨永林 张龙 武艳强 |
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| 作者单位： | 1. 中国地震局地震预测研究所, 地震预测重点实验室, 北京 100036;2. 中国地震局地质研究所, 北京 100029;3. 四川省地震局测绘工程院, 雅安 625000 |
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| 摘 要： | 针对2013年四川芦山7.0级地震震源机制与GPS同震位移场不完全一致的问题，利用高精度水平仪对LS05、LS06等6个GPS连续观测临时站观测墩进行了倾斜测量，对SCTQ墩面水准点高差进行了复测，并对该区域地表变形进行了调查。倾斜测量结果表明，LS06等5个站观测墩相对建站时均无明显倾斜。LS05站观测墩标的确相对建站时发生了倾斜，估计其倾斜量在0.4°～1.2°，倾斜方向以NW为主。无论该点倾斜发生于哪个时段，均不影响同震位移以S向运动为主的特征。对SCTQ基准站观测墩面水准测量结果表明，该站点观测墩非常稳定，未发生倾斜。野外地表调查表明，地壳挤压缩短变形特征较为明显，LS05测点周边确有SW向加速运动和剪切变形现象。综合分析认为，LS05、SCTQ和LS06等GPS测点表现出的左旋应变释放特征真实可靠。
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| 关 键 词： | 芦山地震 同震位移 剪切变形 倾斜测量 地表调查 |
| 收稿时间： | 2013-10-21 |
| 修稿时间： | 2014-03-19 |
VERIFICATION RESEARCH ON THE COSEISMIC DISPLACEMENT OF THE APRIL 20, 2013, M7.0 LUSHAN EARTHQUAKE AND PRIMARY EXPLORATION OF SURFACE DEFORMATION MODE |
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| WEI Wen-xin,JIANG Zai-sen,ZOU Zhen-yu,YANG Yong-lin,ZHANG Long,WU Yan-qiang.VERIFICATION RESEARCH ON THE COSEISMIC DISPLACEMENT OF THE APRIL 20, 2013, M7.0 LUSHAN EARTHQUAKE AND PRIMARY EXPLORATION OF SURFACE DEFORMATION MODE[J].Seismology and Geology,2014,36(2):333-343. |
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| Authors: | WEI Wen-xin JIANG Zai-sen ZOU Zhen-yu YANG Yong-lin ZHANG Long WU Yan-qiang |
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| Affiliation: | 1. Key Laboratory of Earthquake Prediction, Institute of Earthquake Science, China Earthquake Administration, Beijing 100036, China;2. Institute of Geology, China Earthquake Administration, Beijing 100029, China;3. Survey Engineering Institute, Earthquake Administration of Sichuan Province, Ya'an 625000, China |
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| Abstract: | Considering the inconsistence of the focal mechanisms of the M7.0 Lushan, Sichuan earthquake of 2013 with the GPS coseismic displacement field, high-precision gradienter was used to measure the inclination of piers at 6 temporary GPS continuous observation stations, such as LS05, LS06 and so on. Repeat measurement was carried out on the elevation difference of the benchmark on the pier surface of SCTQ, and the surface deformation of this area was investigated. (1)The results of tilt measurement show that there was no obvious tilt for the piers at 5 stations, such as LS06, compared with the period when they were built. The pier at LS05 tilted relative to the time when it was built, with the amount of tilt estimated to be 0.4°～1.2°, and a dominant tilt direction in NW. No matter when the inclination of this pier occurred, the southward movement in the coseismic displacement was dominating. (2)The leveling results of SCTQ station pier surface show that there was no tilt at this site and it was a stable observation point. (3)Field surveys show obvious features of compression-shortening deformation of the crust. Around the site LS05, there were evidences of accelerated SW-directed motion and shear deformation. In summary, the characteristics of left-lateral strain release displayed at the GPS observation sites LS05, SCTQ and LS06 are reliable. |
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| Keywords: | Lushan earthquake coseismic displacement shear deformation tilt measurement surface investigation |
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