High-resolution velocity structure and seismogenic potential of strong earthquakes in the Bamei-Kangding segment of the Xianshuihe fault zone
文献类型：CNKI期刊论文
| 作者 | Yan ZHAO ; Junlun LI; Jian XU; Huajian YAO; Gaohua ZHU; Hongfeng YANG; Jinyu ZHANG; Renqi LU
|
| 发表日期 | 2023-08-18 |
| 出处 | Science China(Earth Sciences)
 |
| 关键词 | Xianshuihe fault zone Bamei-Kangding segment Luding earthquake Dense-array ambient noise tomography Seismogenic environment for moderate to strong earthquakes |
| 英文摘要 | On September 5, 2022, a strong MS6.8 earthquake struck the Luding area in the Kangding-Moxi segment of the Xianshuihe fault zone, which is the northern boundary of the Sichuan-Yunnan rhombic block, causing considerable casualties. The Bamei-Kangding segment of the Xianshuihe fault zone, which is located only tens of kilometers away from the Luding earthquake, has hosted frequent moderate to strong earthquakes in history and is a dangerous earthquake-prone zone. Therefore, it is critical to investigate the regional seismogenic environment for strong earthquakes and to evaluate the impact of the Luding earthquake in this area. For this purpose, we deployed a dense seismic array comprising over 200 short-period nodes in this region from July to August, 2022 and acquired seismic ambient noise for over 30 days. Using the collected data, we conducted surface wave tomography and obtained a high-resolution 3-D shear wave velocity model for the regional shallow crust down to 8 km in depth. The key findings include:(1) the Bamei-Kangding segment of the Xianshuihe fault zone exhibits widespread stripped lowvelocity anomalies, suggesting shear movements at a relatively high temperature of the Xianshuihe fault zone; the Zheduoshan granitic pluton situated between the Zheduotang and southern Selaha faults shows a distinct low-velocity anomaly, which may be attributed to the localized high-temperature anomaly resulted by a deep magmatic heat source and the recent rapid uplift of the Zheduoshan area;(2) a ten-kilometer-wide high velocity body found below 4 km in depth near the Zhonggu area in the Bamei segment coincides with the seismic gap of moderate to strong earthquakes in this region, suggesting that the high velocity body may act as a seismic barrier;(3) the heterogeneity of the velocity structure along the Bamei-Kangding segment of the Xianshuihe fault zone corresponds to the regional changes in temperature, which reveals the reason for the spatially varying seismogenic potential in this segment; especially, the Selaha and Zheduotang faults which are located along the boundaries between the high and low velocity anomalies may possess considerable seismogenic potential;(4) the Coulomb failure stress calculations indicate that the Luding earthquake has imposed nontrivial stress loading in the Bamei-Kangding segment, and may shorten the earthquake recurrence intervals of the southern Selaha fault, the Zheduotang fault, and the Xuemenkan segment of the Xianshuihe fault zone.Thus, the Luding earthquake may potentially pose threats to the Sichuan-Xizang railway passing through this region. |
| 文献子类 | CNKI期刊论文 |
| 资助机构 | supported by the National Key Research and Development Project of China (Grant No. 2021YFC3000602) ; the Special Fund of Key Laboratory of Earthquake Prediction, CEA (Grant No. 2021IEF0103) |
| 卷 | v.66期:09页:48-66 |
| 语种 | 英文; |
| 分类号 | P315.2 |
| ISSN号 | 1674-7313 |
| 源URL | [http://ir.qdio.ac.cn/handle/337002/187028]  |
| 专题 | 中国科学院海洋研究所 |
| 作者单位 | 1.LaboratoryofSeismologyandPhysicsoftheEarth'sInterior,SchoolofEarthandSpaceSciences,UniversityofScienceandTechnologyofChina 2.MengchengNationalGeophysicalObservatory,UniversityofScienceandTechnologyofChina 3.CASCenterforExcellenceinComparativePlanetology 4.EarthSystemScienceProgramme,FacultyofScience,TheChineseUniversityofHongKong 5.StateKeyLaboratoryofEarthquakeDynamics,InstituteofGeology,ChinaEarthquakeAdministration 6.KeyLaboratoryofMarineGeologyandEnvironment,CAS |
| 推荐引用方式 GB/T 7714 | Yan ZHAO,Junlun LI,Jian XU,et al. High-resolution velocity structure and seismogenic potential of strong earthquakes in the Bamei-Kangding segment of the Xianshuihe fault zone. 2023. |
入库方式： OAI收割
来源：海洋研究所
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