海底地震仪垂直分量倾斜噪声的去除以磐鲲南海测试数据为例  

Removing tilt noise from the vertical component data of ocean bottom seismograph:A case study on the data from the Pankun test in the South China Sea

作　　者：吴越楚 杨挺 Wu Yuechu;Yang Ting(OBS Laboratory,Department of Ocean Science and Engineering,Southern University of Science and Technology,Guangdong Shenzhen 518055,China;Shanghai Sheshan National Geophysical Observatory,Shanghai 201600,China;Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou),Guangzhou 510301,China)

机构地区：[1]南方科技大学海洋科学与工程系海底地震仪实验室,广东深圳518055 [2]上海佘山地球物理国家野外科学观测研究站,上海201600 [3]南方海洋科学与工程广东省实验室(广州),广州510301

出　　处：《地震学报》2023年第3期568-578,共11页Acta Seismologica Sinica

基　　金：国家自然科学基金(92058209);深圳市科创委项目(KQTD20170810111725321,JCYJ20180504170422082)共同资助.

摘　　要：基于水平分量和垂直分量噪声数据之间的相关性,可以通过水平到垂直分量的传递函数去除垂直分量的倾斜噪声。本文以2019—2020年磐鲲海底地震仪南海测试的数据为例,描述了该方法的原理和过程,并对比了去除倾斜噪声前后的地震波形以及瑞雷波的频散特征。结果表明:倾斜噪声的去除明显提高了海底地震仪的低频段地震波形的信噪比,使得地震面波更有利于海洋岩石圈深部结构成像;此外,尽管磐鲲海底地震仪的调平系统使地震计的倾角(1.0°)远小于其容倾角(2.5°),在底流作用下,海底地震仪还是产生了明显的倾斜噪声。因此,地震仪调平系统的性能对海底地震仪的数据质量有着非常重要的影响。Based on the correlations between the noise data of the horizontal and the vertical components,we can remove the tilt noise from the vertical component by using the transfer function of the horizontal-to-vertical component.Using the data from the 2019−2020 Pankun OBS South China Sea test,this paper describes the theory and process of this method.It compares the seismograms before and after removing the tilt noise and highlights the improvement of the dispersions of Rayleigh surface waves.The results show that removing tilt noise can improve the signal-to-noise ratio of seismograms for the OBS data in the low-frequency range,resulting in surface waves more conducive to imaging the deep structure of the oceanic lithosphere.This study also shows that although the tilt angle(1.0°)of the seismometer of Pankun OBS is much smaller than the tolerance of the tilt angle of the instrument(2.5°),the bottom currents still generate a significant level of tilt noise on OBS data.Therefore,the leveling system of the instrument is a crucial component affecting the OBS data quality.

关 键 词：海底地震仪 地震噪声 倾斜噪声 噪声去除 

分 类 号：P315.73[天文地球—地震学]