| 腾冲火山及周边地区双差层析成像 |
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| 引用本文： | 华雨淋,吕彦.腾冲火山及周边地区双差层析成像[J].地球物理学报,2019,62(8):2982-2990. |
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| 作者姓名： | 华雨淋 吕彦 |
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| 作者单位： | 1. 中国科学院地质与地球物理研究所, 中国科学院地球与行星物理重点实验室, 北京 100029;2. 中国科学院地球科学研究院, 北京 100029;3. 中国科学院大学, 北京 100049 |
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| 基金项目： | 国家自然科学基金项目（41674066，41874066）资助. |
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| 摘 要： | 利用云南腾冲火山地区15个固定台站记录到的7923次地震的P波到时资料，采用双差层析成像方法，反演得到腾冲火山及周边地区地壳及上地幔顶部三维P波速度结构和地震重定位结果.研究发现，腾冲火山区域地壳内存在明显的地震波低速区，P波速度低于整个区域地壳速度平均值超过15%，上地幔顶部存在规模较大的低速异常区.推测腾冲火山地区存在较大规模的地幔热物质上涌以及向地壳的侵入，热物质在地壳内以岩浆囊形式存储，并且壳内岩浆囊之间可能存在岩浆通道.通过联合反演获得的地震重定位结果显示，丛集地震位置更加集中，其展布特征与断裂构造具有显著的对应关系，表明研究区域断裂构造比较活跃.获得的高分辨率三维P波层析成像结果，为进一步认识火山地区岩浆存储特征以及地震分布与区域构造之间的关系提供了新的地震学依据.
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| 关 键 词： | 双差层析成像 腾冲火山地区 岩浆囊 |
| 收稿时间： | 2018-04-28 |
Double differential tomography of the Tengchong volcano and adjacent areas |
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| HUA YuLin,Lü Yan.Double differential tomography of the Tengchong volcano and adjacent areas[J].Chinese Journal of Geophysics,2019,62(8):2982-2990. |
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| Authors: | HUA YuLin Lü Yan |
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| Institution: | 1. Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China;2. Institutions of Earth Science, Chinese Academy of Sciences, Beijing 100029, China;3. University of Chinese Academy of Sciences, Beijing 100049, China |
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| Abstract: | Based on 7923 P-wave arrivals recorded by 15 stations of the seismic network, this work relocated earthquakes and imaged the velocity structure beneath the Tengchong volcano and adjacent areas by the double differential tomography. Research found the existence of low P-wave velocity zones in the crust beneath the Tengchong volcano, more than 15% lower than the average velocity of the entire study area. Large-scale low-velocity anomalies are present in the upper mantle. We infer that there are hot material upwelling from the mantle and intrusion into the crust beneath the volcanic area. Thermal material is stored in the form of magma chambers and magma channels may exist between the magma chambers in the crust. The earthquakes after relocation are more concentrated, and their distribution characteristics are in good agreement with the fault structure, implying the faults in this area are active. The high-resolution 3D P-wave tomography results of this study provide new evidence for further understanding of the characteristics of magma storage in volcanic regions and the relationship between earthquake distribution and regional tectonics. |
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| Keywords: | Double differential tomography Tengchong volcanic area Magma chamber |
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