| 摘要: |
| 2017年8月8日九寨沟发生7.0级地震，此次地震发生在塔藏断裂、岷江断裂和虎牙断裂附近，震源机制为走滑型。重力场静态异常和动态异常变化可为研究深地壳结构性质提供重要的物理场信息。本文利用WGM计算的布格重力异常数据及实测流动重力数据进行小波多尺度分解，分离得到不同深度场源特征的地壳介质横向不均匀性。结果表明，WGM布格重力异常数据和实测重力数据的小波多尺度结果较为一致，通过对比分析发现，九寨沟地震发生在区域重力场的四象限分布中心位置，不同时空尺度的重力场变化对于深入认识潜在地震危险性趋势具有一定的科学意义。 |
| 关键词: 九寨沟7.0级地震 重力场 小波分解 多尺度 |
| DOI： |
| 分类号:P315 |
| 基金项目:国家自然科学基金（61627824）、川滇国家地震监测预报实验场项目（2016CESE0202）及震情跟踪青年课题（2017010227）共同资助 |
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| Gravity field anomaly feature extraction before the Jiuzhaigou earthquake in 2017 |
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Liu Fang1, Zhu Yiqing1, Zhao Yunfeng1, Liu Tao2
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1.Second Crust Monitoring and Application Center, CEA, Xi'an 710054, China;2.Research Institute of Yanchang Petroleum(Group) Co., Ltd., Xi'an 710075, China
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| Abstract: |
| The Jiuzhaigou MS7.0 earthquake on August 8, 2017 occurred in the vicinity of the Tazang fault, the Minjiang fault and the Huya fault, which belong to the strike slip type. The static and dynamic anomalies of gravity field can provide important physical field information for studying the structural properties of deep crust. We use multi-scale decomposition technique to separate bouguer gravity at different depths and give some explanation to gravity variations at different time space scales. The results indicate that the wavelet multi-scale results of the EGM2008 model and the measured gravity data are consistent. Through comparative analysis, it is found that the Jiuzhaigou earthquake occurred in the stress enhanced region. The variation of gravity field at different time scales has a certain scientific significance for further understanding of the potential earthquake risk trend. |
| Key words: The Jiuzhaigou MS7.0 earthquake Gravitational field Wavelet decomposition Multi-scale |
