东太平洋Juan de Fuca板块的大地电磁研究

地震地质 ›› 1990, Vol. 12 ›› Issue (2): 159-167.

东太平洋Juan de Fuca板块的大地电磁研究

赵国泽¹, 行武毅², 浜野洋三², 歌田久司², 濑川尔朗³, J. H. Filloux⁴, L. K. Law⁵, T. White⁶, A. D. Chave⁷, P. Tarits⁸

1. 国家地震局地质研究所;
2. 日本东京大学地震研究所;
3. 日本东京大学海洋研究所;
4. 美国加理福尼亚大学斯河利浦海洋研究所;
5. 加拿大地质调查所;
6. 澳大利亚弗林德斯大学;
7. 美国AT和T贝尔实验室;
8. 法国地球物理研究所

收稿日期:1989-05-31 出版日期:1990-06-06 发布日期:2009-11-25
基金资助:
日本学术振兴会

THE INVESTIGATION ON MAGNETOTELLURIC DATA OF THE JUAN DE FUCA PLATE

Zhao Guo-ze¹, T. Yukutake², Y. Hamano², H. Utada², J. Segawa³, J. H. Filloux⁴, L. K. Law⁵, T. White⁶, A. D. Chave⁷, P. Tarits⁸

1. Institute of Geology, State Seismological Bureau, Beijing, China;
2. Earthquake Research Institute, University of Tokyo, Tokyo, Japan;
3. Ocean Research Institute, University of Tokyo, Tokyo, Japan;
4. Scripps Institution of Oceanography, University of California, San Diago, La Jolla, CA, U. S. A.;
5. Pacific Geoscience Centre, Geological Survey of Canada, Sidney, BC, Canada;
6. Flinders University, Dedford Park, S. A., Australia;
7. AT. &T Bell Laboratories, Murray Hill, NJ, U. S. A.;
8. Institut de Physique du Globe, Paris, Prance

Received:1989-05-31 Online:1990-06-06 Published:2009-11-25

摘要/Abstract

摘要： 本研究做为电磁感应国际合作研究项目—EMSLAB计划的一部分,主要目的在于确定东太平洋年轻的海洋板块——JuandeFuca板块及其周围地区岩石圈和软流圈的电性结构。在对海底观测的大地电磁资料定性和定量分析的基础上,进行了二维数学模拟。在二维模型中,海洋地形和已知的表层构造被确定。通过改变模型的重要参数,评价响应函数和观测资料之间偏差的增加,检验模型的可靠性。结果表明,JuandeFuca板块深部存在两个导电层,一个在40km,另一个在200km左右。这里岩石圈比其它较老板块的岩石圈薄。

关键词: Juan de Fuca板块, 阻抗旋转, 层状模型反演, 二维模拟导电层和电阻层

Abstract: As a part of the EMSLAB project,the principal purpose of the study is to provide the constraints on electrical structures of the lithosphere and asthenosphere beneath Juan de Fuca plate and its vicinity.We have carried out two-dimensional modelling of the magnetotelluric data provided by EMSLAB group. One-dimensional method has been used in inversion,and then finite clement method used in two-dimensional modelling. The known superficial features are determined at various stages of the modelling. In order to confirm the uniqueness of the model,we have changed some important parameters of the model and assessed the increase of misfit.The model with best-fitting data shows that the lithosphere of the Juan de Fuca plate is a resistive layer with a thickness of about 40km,which is thinner than that of the older plate. The thickness of the asthenosphere is about 60km,underlain by less resistive layer overlapping a conductive half space.

Key words: Juan de Fuca plate, Rotation of impedance tensor, Inversion by layer model, 2-D modelling, Electricity layer

赵国泽, 行武毅, 浜野洋三, 歌田久司, 濑川尔朗, J. H. Filloux, L. K. Law, T. White, A. D. Chave, P. Tarits. 东太平洋Juan de Fuca板块的大地电磁研究[J]. 地震地质, 1990, 12(2): 159-167.

Zhao Guo-ze, T. Yukutake, Y. Hamano, H. Utada, J. Segawa, J. H. Filloux, L. K. Law, T. White, A. D. Chave, P. Tarits. THE INVESTIGATION ON MAGNETOTELLURIC DATA OF THE JUAN DE FUCA PLATE[J]. SEISMOLOGY AND GEOLOGY, 1990, 12(2): 159-167.