海浪感应电磁场的理论计算
Theoretical calculation of electromagnetic field generated by ocean waves
-
摘要: 根据麦克斯韦电磁理论,在地磁场中运动的海水将产生感应电磁场。利用一个简单的数学物理模型对感应电磁场在海水内部的分布进行了计算,结果表明海浪产生的电磁场明显依赖于海浪波动的周期及浪高。在100 m的海水深度内,海浪产生的磁感应强度的大小为纳特数量级,而电场强度的大小为几个微伏每米。在同一海水深度处,磁感应强度随海水波动的周期呈现近线性变化,而电场强度的大小有一个极值,该极值随海水深度的增加向长周期方向移动。海浪产生的电磁场是影响海洋电磁探测数据精度的主要噪声之一。Abstract: According to the Maxwell electromagnetic theory, motion of ocean waves will generate electromagnetic field.On the basis of a simple mathematic- physical model, the distribution of the electromagnetic field in the ocean is calculated.Results show that the electromagnetic field strongly depends on the period and amplitude of ocean waves.Within 100 m depth the amplitude of the magnetic field is in the order of nanotesla.The electric field is a few microvolts permetre.In the same depth, the magnetic field presents a near-linear tendency with the ocean wave depth.For the electric field, a maximum value is observed, which moves to the long period direction with the depth increase.The electromagnetic field is a major reason to influence the accuracy of the marine electromagnetic prospecting data.
-
Key words:
- ocean waves /
- Maxwell equations /
- electromagnetic field
-
文圣常,余宙文.海浪理论与计算原理[M].北京:科学出版社,1985. WEAVER J T.Magnetic variations associated with ocean waves and swell[J].Journal of Geophysical Research,1965,70:1921-1929. LARSEN J C.An introduction to electromagnetic induction in the ocean[J].Physics of the Earth and Planetary Interiors,1973,7:38 9-3 98. MACLURE K C,HAFER R A,WEAVER J T.Magnetic variations produced by ocean swell[J].Nature,1964,204:1290-1291. FRASER D C.Magnetic field of ocean waves[J].Nature,1965,206:605-606. FRASER D C.The magnetic fields of ocean swell[J].Geophys J R Astr Soc,1966,11:507-517. KOZLOV A N,FONAREV G A,SHUMOV L A.Results of observations of the magnetic field of sea waves[J].Geomagn Aeron,1971,11:633. LILLEY F E M.Sea-surface observations of the magnetic signals of ocean swells[J].Geophysical Journal International,2004,159:565-572. 魏文博,邓明,谭捍东.等.利用海底大地电磁探测研究南海地壳电性结构的必要性[M]//苏纪兰.南海环境与资源基础研究前瞻.北京:海洋出版社,2001:123-13Z. 叶安乐.李风歧.物理海洋学[M].青岛:青岛海洋大学出版社,1990. MUNK W H,MILLER G R,SNODGRASS F E.Directional recording of swell from distant storms[J].Phil Trans Roy Soc,London,1962,254:565-584. 魏文博,邓明.谭捍东,等.我国海底大地电磁探测技术研究的进展[J].地震地质,2001,23(2):131-137. -
点击查看大图
计量
- 文章访问数: 692
- HTML全文浏览量: 5
- PDF下载量: 1593
- 被引次数: 0
下载:
