Progress in the studies of the seismic gap between the 2008 Wenchuan and 2013 Lushan earthquakes
文献类型：期刊论文
| 作者 | Liang ChunTao1,2; Huang YanLing2; Wang ChaoLiang2; Liu ZhiQiang2; Yang YiHai3; Wu Jin4; He FuJun2 |
| 刊名 | CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION
 |
| 出版日期 | 2018-05-01 |
| 卷号 | 61期号:5页码:1996-2010 |
| 关键词 | Seismic gap Receiver function Stress inversion Micro-seismicity |
| ISSN号 | 0001-5733 |
| DOI | 10.6038/cjg2018M0254 |
| 文献子类 | Article |
| 英文摘要 | The purpose of this work is to investigate the deep structure beneath the seismic gap between the 2008 Wenchuan and 2013 Lushan earthquakes, discuss the geodynamic process of the movement of materials, and to assess the seismic potential in this region. We have conducted two phases of seismic observations with more than 100 temporary instruments deployed in the last three years. The preliminary results indicate that (1) the seismic gap serves as a transition zone separating two distinct stress regimes, and the fault-parallel stress difference is observed between the two sides of the gap. (2) The receiver function analysis shows that a long belt of Moho uplift extends from the gap to the Longriba fault, roughly aligning with the Barkam fault. The Poisson's ratio is relatively high along this belt. A partial melting at the lower crust along this belt may explain these observations. (3) Beneath the seismic gap, the velocity in the upper crust is relatively low and a thickened lower crust may indicate the existence of partial melting in the lower crust. These two observations may explain the absence of seismicity in the seismic gap. (4) Micro-seismicity was studied using a matched filter method. Given the complete magnitude of earthquakes being lowered from 1.4 to 0.2, the seismic gap is still void of events compared to the two sides of the gap; seismic locations are also obtained by traveltimes recorded by the densest array in the region deployed recently. The seismicity is still void of events, but a linear strip of seismicity was observed to the east of the seismic gap and it aligns roughly with the Dayi fault and/or other blind faults in the region. These faults could be the structure to yield big events in the future. (5) Based on the above observations, we propose a new model to account for the geodynamics of the seismic gap; the fault-parallel stress difference across the gap may imply that the gap is the point where the crust of the eastern Tibetan plateau is being torn apart, resulting in the upwelling of hot mantle materials to produce partial melting in the lower crust. This partial melting may heat up the upper crust beneath the gap and turn the faults in this segment into aseismic. The tearing apart fracture of the crust may extend all the way to the Barkam fault, but it less developed further away from the seismic gap in the Longmenshan fault system. |
| WOS关键词 | FOCAL MECHANISM SOLUTIONS ; LOWER CRUSTAL FLOW ; TIBETAN PLATEAU ; LONGMEN SHAN ; TECTONIC DEFORMATION ; EASTERN MARGIN ; STRESS-FIELD ; CHINA ; SEQUENCE ; NORTH |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:000432644000027 |
| 出版者 | SCIENCE PRESS |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/88243]  |
| 专题 | 中国科学院地质与地球物理研究所 |
| 通讯作者 | Liang ChunTao |
| 作者单位 | 1.Chengdu Univ Technol, State Key Lab Geohazard Prevent & Geoenvironm Pro, Chengdu 610059, Sichuan, Peoples R China 2.Chengdu Univ Technol, Minist Educ, Key Lab Earth Explorat & Informat Technol, Chengdu 610059, Sichuan, Peoples R China 3.Shaanxi Earthquake Adm, Xian 710068, Shaanxi, Peoples R China 4.Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China |
| 推荐引用方式 GB/T 7714 | Liang ChunTao,Huang YanLing,Wang ChaoLiang,et al. Progress in the studies of the seismic gap between the 2008 Wenchuan and 2013 Lushan earthquakes[J]. CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION,2018,61(5):1996-2010. |
| APA | Liang ChunTao.,Huang YanLing.,Wang ChaoLiang.,Liu ZhiQiang.,Yang YiHai.,...&He FuJun.(2018).Progress in the studies of the seismic gap between the 2008 Wenchuan and 2013 Lushan earthquakes.CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION,61(5),1996-2010. |
| MLA | Liang ChunTao,et al."Progress in the studies of the seismic gap between the 2008 Wenchuan and 2013 Lushan earthquakes".CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION 61.5(2018):1996-2010. |
入库方式： OAI收割
来源：地质与地球物理研究所
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