陈栋炉^1,,
林建民^1,,,
倪四道²,
祝翔宇³,
郑红¹
1. 浙江海洋大学海洋科学与技术学院, 浙江舟山 316022
2. 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
3. 宁波市海洋与渔业信息监测中心, 浙江宁波 315141

基金项目: 国家自然科学基金（41104027），浙江省自然科学基金重点项目（LZ14D060001），大地测量与地球动力学国家重点实验室开放基金（SKLGED2013-1-7-E）和中国科学院重要方向性项目（KZCX2-EW-121）共同资助


详细信息

作者简介: 陈栋炉, 女, 1992年生, 硕士研究生, 主要从事声学海洋学研究.E-mail:cdllilly@sina.com

通讯作者: 林建民, 男, 博士, 硕士生导师, 主要从事海洋地球物理和声学海洋学研究.E-mail:jmlin007@zjou.edu.cn

中图分类号: P315

收稿日期:2017-01-16
修回日期:2017-03-07
上线日期:2018-01-05

Characteristics of seismic noise on ocean islands in Northwest Pacific and its oceanographic interpretation

CHEN DongLu^1,,
LIN JianMin^1,,,
NI SiDao²,
ZHU XiangYu³,
ZHENG Hong¹
1. School of Marine Science and Technology, Zhejiang Ocean University, Zhoushan Zhejiang 316022, China
2. State Key Laboratory of Geodesy and Earth's Dynamics, Institute of Geodesy and Geophysics, Chinese Academy of Sciences, Wuhan 430077, China
3. Ningbo Marine and Fisheries Information Monitoring Centre, Ningbo Zhejiang 315141, China


More Information

Corresponding author: LIN JianMin,E-mail:jmlin007@zjou.edu.cn

MSC: P315

--> Received Date: 16 January 2017
Revised Date: 07 March 2017
Available Online: 05 January 2018


摘要
摘要:地震背景噪声特性及噪声源的分布研究逐渐成为深化背景噪声层析成像的关键问题.海岛地区由于特殊的地理位置，其背景噪声具有相对独特的特征.地脉动（约0.003~1 Hz）是地震背景噪声中能量最强的分量，其激发与特性被认为与海浪运动和固体地球之间的相互作用有关，但海岛地区地脉动特征与海洋波浪场之间的关系尚未被充分研究.本文利用西北太平洋海岛地震台站的连续记录数据、波浪浮标的实测数据以及WAVEWATCH-Ⅲ海浪模式的数值模拟结果，通过地震学和海洋学的交叉，分析海岛地区地脉动信号的时频特性及其与海洋波浪场之间的相关性，从海洋学角度对地脉动信号的特征及激发进行探讨与解释.结果表明，海岛地区地脉动信号相对于内陆地区更强，并具有明显且稳定的季节性变化特征：高频地脉动信号（0.12~0.32 Hz）在夏秋季节（5月-10月）相对较弱，而在冬春季节（11月-次年4月）相对较强，与北半球海洋活动季节性变化相一致.此外，海岛地区地脉动主要受周边海域波浪场影响，与周边海域波浪能功率密度及实测和数值模拟所得的有效波高均具有很好的互相关性.该研究结果同时表明可进一步发展利用地脉动观测数据反演海表波浪场的可能，为海洋科学研究中海表波浪场连续观测数据的获取提供地震学上的支持.
关键词: 海岛/
地震背景噪声/
地脉动/
时频特性/
海浪/
台风

Abstract:Characteristics of seismic noise and spatial distribution of its sources have become the key issue for the further development of ambient noise tomography method. Seismic noise on ocean islands has its special features for being geographically isolated. Microseisms (~0.003-1 Hz) are the most energetic component of seismic noise, and their generation has been thought to be related with the interaction between ocean waves and the solid Earth. However, the relationship between microseisms on ocean islands and ocean wave field has not yet been fully investigated. This study investigates the temporal frequency characteristics of microseisms on ocean islands and its correlations with ocean wave field through interdisciplinary study between seismology and oceanography, using seismic wave records from island seismic stations in the Western North Pacific, continuous observation from moored ocean wave buoy, and numerical modeling by WAVEWATCH-Ⅲ ocean wave model. We find that microseisms on ocean islands are much stronger than in inland regions, and have distinct and steady seasonal variations. Microseisms in the frequency band of 0.12~0.32 Hz become weaker in seasons of summer and autumn (from May to October), while they become stronger in the seasons of winter and spring (from November to next April), which is consistent with the seasonal variation of oceanographic activities in the Northern hemisphere. In addition, the microseisms on ocean islands are found to be highly correlated with the ocean wave energy over the adjacent sea and significant ocean wave height from both observation and numerical modeling, which shows that the microseisms are mainly affected by adjacent ocean wave field. This study result also proves the possibility of seismological inversion of ocean wave field using microseismic signals, providing potentially a new supplementary approach of ocean wave observation to the marine science community.
Key words:Ocean island/
Seismic noise/
Microseisms/
Temporal frequency characteristics/
Ocean wave/
Typhoon



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