| 汉中盆地及邻区地壳结构和地震活动性研究 |
| |
| 引用本文： | 危自根,储日升,杨小林,谢军,田忠华,凌媛,董非非.汉中盆地及邻区地壳结构和地震活动性研究[J].地震学报,2019,41(4):445-458. |
| |
| 作者姓名： | 危自根 储日升 杨小林 谢军 田忠华 凌媛 董非非 |
| |
| 作者单位： | 中国武汉 430077 中国科学院测量与地球物理研究所;中国武汉 430077 大地测量与地球动力学国家重点实验室;中国武汉 430077 中国科学院测量与地球物理研究所;中国西安 710068 陕西省地震局;中国北京 100037 中国地质科学院地质研究所;中国北京 100029 中国科学院地质与地球物理研究所;中国北京 100029 中国科学院地球与行星物理重点实验室;中国南昌 330039 江西省地震局 |
| |
| 基金项目： | 国家重点研发计划 “深地资源勘查开采” 重点专项（2016YFC0600402）和国家自然科学基金（41604056）联合资助 |
| |
| 摘 要： | 为了进一步探查汉中盆地的深部动力学机制和孕震构造特征，本文基于背景噪声成像、多频接收函数和面波联合反演以及莫霍面Ps震相时深转换方法反演了汉中盆地及其邻区的地壳S波速度和厚度，并进一步对比分析了研究区深部结构与地震活动性之间的关系。结果表明:汉中盆地不同区域的浅表沉积厚度和速度存在差异；部分区域莫霍面处的速度变化平缓，Ps震相与P震相的振幅比＜0.2；汉中盆地内部鲜有地震发生，其周边10 km范围内地震分布主要受到断层控制；4—16 km震源深度上下界面大致对应于低速体底层和高速体顶层。本文获得的非均匀分布的沉积厚度、渐变的壳幔过渡带结构与汉中盆地长期处于秦岭构造带、大巴山褶皱带以及青藏地块交界区的三联点构造位置密切相关。
|
| 关 键 词： | 汉中盆地 地壳结构 地震活动性 背景噪声成像 接收函数 |
| 收稿时间： | 2018-12-17 |
Crustal structure and seismic activity in the Hanzhong basin and its adjacent areas |
| |
| Abstract: | In order to explore the deep dynamic mechanism and seismogenic structural characteristics in the Hanzhong basin, this paper used the ambient noise tomography, joint inversion of the multi-frequency receiver function and surface wave, and the time-depth conversion method of Ps phase from the Moho to image the crustal S-wave velocity and thickness in the Hanzhong basin and its adjacent areas. Then, we further analyzed the relationship between the crustal structure and seismic activity in the studied region. The results show that the sedimentary thickness and velocity of shallow surface are different in different areas of the Hanzhong basin; in some areas of the studied region Moho surface varies gently with a Ps/P ratio less than 0.2. There are few earthquakes in the Hanzhong basin, and the earthquake distribution within 10 km around the basin is mainly controlled by faults. The upper and lower interfaces of the focal depth （4?16 km） correspond to the bottom of the low-velocity region and the top of the high-velocity region, respectively. The uneven sedimentary thickness and gradual crust-mantle transitional zone obtained in this paper are closely related to the triple junction tectonic position of the Hanzhong basin among the Qinling tectonic belt, the Dabashan folded belt and the Tibetan Plateau. The crustal structure and seismicity characteristics obtained in this paper can provide useful information for the study on the deep dynamic mechanism and seismogenic environment in the Hanzhong basin. |
| |
| Keywords: | |
| 本文献已被 万方数据 等数据库收录！ |
| 点击此处可从《地震学报》浏览原始摘要信息 |
| 点击此处可从《地震学报》下载免费的PDF全文 |
