曾求^1,2,,
储日升^1,,,
曾祥方¹,
崇加军¹
1. 中国科学院测量与地球物理研究所大地测量与地球动力学国家重点实验室, 武汉 430077
2. 中国科学院大学地球与行星科学学院, 北京 100049

基金项目: 国家重点研发计划(2018YFC1504200), 国家自然科学基金国际(地区)合作与交流项目(41661164035)资助


详细信息

作者简介: 曾求, 男, 硕士研究生, 主要从事地震背景噪声成像研究.E-mail:chow@whigg.ac.cn

通讯作者: 储日升, 男, 研究员, 博士生导师, 主要从事地震学和地球动力学研究.E-mail:chur@asch.whigg.ac.cn

中图分类号: P315

收稿日期:2019-05-26
修回日期:2019-07-30
上线日期:2020-05-05

Extraction of high-frequency surface waves on the Xishancun landslide from ambient seismic noises

ZENG Qiu^1,2,,
CHU RiSheng^1,,,
ZENG XiangFang¹,
CHONG JiaJun¹
1. State Key Laboratory of Geodesy and Earth's Dynamics, Institute of Geodesy and Geophysics, Chinese Academy of Sciences, Wuhan 430077, China
2. College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China


More Information

Corresponding author: CHU RiSheng,E-mail:chur@asch.whigg.ac.cn

MSC: P315

--> Received Date: 26 May 2019
Revised Date: 30 July 2019
Available Online: 05 May 2020


摘要
摘要:滑坡体三维速度结构为滑坡治理、灾害防治、风险防范以及理解滑坡的动力学过程提供了关键信息，而高频面波成像是研究浅层速度结构的重要手段.本文详细介绍了利用2016年12月1日在四川理县西山村滑坡上布设的38个仪器记录的三分量连续地震噪声数据，提取1~5 Hz的基阶Love波和Rayleigh波经验格林函数，分析了不同参数和处理方法对背景噪声互相关计算结果的影响.结果表明，1天左右的连续波形记录裁剪至1200 s的时间长度，进行互相关叠加就可以得到较为稳定的经验格林函数.西山村滑坡体上Love波和Rayleigh波的群速度分别为约400 m·s^-1和700 m·s^-1，并且Love波信噪比高于Rayleigh波.此外，我们还利用聚束分析方法对噪声源的位置进行了分析，发现1~5 Hz的背景噪声主要来自滑坡东南侧附近杂谷脑河水的搬运作用.这些高频面波数据和噪声源位置为获取滑坡浅层三维速度结构提供了重要输入，同时也为研究滑坡体速度结构随时间的变化提供了基础.
关键词: 西山村滑坡/
背景噪声互相关/
高频面波信号/
噪声源定位

Abstract:Three-dimensional structures of landslides provide key information to landslide treatment, disaster prevention, and risk mitigation, as well as the understanding of landslide dynamics, while high-frequency surface wave tomography has been proven to be an effective method to image shallow structures. In this study, we attempt to obtain high-frequency surface waves for 38 stations on the Xishancun landslide in southwestern China. We extract empirical Green's functions from three-component continuous ambient seismic noises recorded on December 1^st, 2016. First, we test several parameters that may yield better noise correlation functions (NCFs), including time-segment length, data filtering, and topography effect. After stacking NCFs from one-day noises with a segment length of 1200 s, we obtain clear Love and Rayleigh waves in the frequency range of 1~5 Hz with apparent velocities at about 400 m·s^-1 and 700 m·s^-1, respectively. Love waves generally have higher signal-to-noise ratios than Rayleigh waves. Beamforming of Love waves suggests that the seismic noises mainly come from the sediment transport of the river to the south toe of the landslide. The obtained surface waves and location of seismic noises provide a valuable input for 3D tomography of the shallow structures of the Xishancun landslide, as well as their temporal variations.
Key words:The Xishancun landslide/
Ambient noise correlation/
High-frequency surface waves/
The location of the noise source



PDF全文下载地址:

http://www.geophy.cn/data/article/export-pdf?id=dqwlxb_15449