基于短周期密集地震台阵观测的空间自相关法及其在粤港澳大湾区的应用  

Spatial autocorrelation method based on dense short-period seismic array and its application in the Guangdong-Hong Kong-Macao Greater Bay

作　　者：潘啟安 沈旭章 Pan Qi’an;Shen Xuzhang(School of Earth Science and Engineering,Sun Yat-Sen University,Guangzhou 510275,China;Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),Guangdong Zhuhai 519080,China)

机构地区：[1]中山大学地球科学与工程学院,中国广州510275 [2]南方海洋科学与工程广东省实验室(珠海),中国广东珠海519080

出　　处：《地震学报》2023年第2期246-257,共12页Acta Seismologica Sinica

基　　金：国家自然科学基金(42230305);第二次青藏高原综合科学考察研究(2019QZKK0701);广东省防震减灾协同创新中心(2018B020207011);广东省引进人才创业创新团队(2017ZT07Z066)共同资助。

摘　　要：基于空间自相关法从粤港澳大湾区短周期密集台阵的21个观测点记录的微动信号中提取了瑞雷波频散曲线,并反演得到了广州市番禺区内布设的台阵下方1 km深度范围内的浅层S波速度结构。结果显示:台阵下方0.25 km深度以内的速度明显偏低,介于1.17 km/s到1.59 km/s之间;0.25—1 km深度之间的速度平稳增加至2.88 km/s,表明通过空间自相关法可以有效地获取观测台阵下方稳定可靠的浅层速度结构。因此短周期密集台阵技术与空间自相关法结合是在人口稠密的城市群地区进行地下浅层的精细结构探测的一种有效、经济、环保的手段,将在未来城市地区的浅层结构探测中发挥重要作用。Based on spatial autocorrelation(SPAC)method,the dispersion curves of Rayleigh wave have been extracted from the microtremor recorded by 21 stations belong to the dense short-period array deployed in Guangdong-Hong Kong-Macao Greater Bay area,and then the inversion for shallow S-wave velocity structures within a depth of 1 km beneath the Panyu district,Guangzhou city,have been performed.The results show that the velocity beneath the array is obviously low within 0.25 km depth,ranging from 1.17 km/s to 1.59 km/s,while the velocity increases steadily to 2.88 km/s between 0.25 km to 1 km depth.This indicates that the stability and the reliability of the method,which also implies that the SPAC is an effective,economical and environmental method for detecting the shallow fine structures in densely populated urban areas,and it will play an increasingly important role in the exploration of shallow structure in urban areas in the future.

关 键 词：短周期密集台阵 空间自相关(SPAC)法 频散曲线 S波速度结构 

分 类 号：P315.31[天文地球—地震学]