Development of Ocean Bottom Electromagnetic Measurement System and Three-dimensional Structure of the Transition Zone between the Ocan and the Continent

海底电磁测量系统研制及海洋与大陆过渡带三维结构

基本信息

批准号：
62840009
负责人：
HAMANO Yozo
金额：
$ 11.65万
依托单位：
Earthquake Research Institute
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research
财政年份：
1987
资助国家：
日本
起止时间：
1987 至 1988
项目状态：
已结题

项目摘要

Purpose of the present investigation is to develope an ocean bottom system which measures the variations of the three components of the magnetic field and two horizontal components of the electric field of the earth. Such a system is required to study the complicated electromagnetic structures beneath the Japanese Islands and the adjacent area. During the studying period of 1987 and 1988, the system named Obem (Ocean Bottom Electric and Magnetic field measurement apparatus) has been completed, and tested at Kakioka Magnetic Observatory of the Meteololgical Agency and Yatsugatake Magnetic Observatory of the University of Tokyo. Druing the development of the apparatus, magnetic sensor, electrode, pressure vessel, measureing circuits, power source, and acoustic release system have been reexamined to fit to the present purpose.The first sea floor measurement by using the presently developed Obem was made during june and November of 1988 at the southern-most part of the Juan de Fuca ridge. The project is a part of the international coopertive study (EMRIDGE project), which aimes to investigate the generating process of the oceanic plate from a detailed study of the electromagnetic structure beneath the ridge system. The present apparatus is suitable for the study, since one instrument can measure a complete set of the electromagnetic signals at the site. The sea floor apparatus including the present one was installed by hakuho-maru which belongs to the Ocean Research institute of the University of Tokyo, and were safely recovered by Canadian research vessel Parizeau.

本研究的目的是开发海底系统，该系统测量磁场的三个组成部分的变化和地球电场的两个水平成分。需要这样的系统来研究日本岛屿和相邻区域下方的复杂电磁结构。在1987年和1988年的研究期间，已经完成了名为OBEM（海洋底部电场和磁场测量设备）的系统，并在Tokyo大学的金属酚局和Yatsugatake磁观测站的Kakioka磁观测器进行了测试。已经重新审查了牙设备，磁性传感器，电极，压力容器，测量电路，电源和声学释放系统的开发，以适应当前目的。使用当前开发的OBEM进行的首次海底测量是在1988年6月和11月在1988年11月在南部的Juan De Fuca Ridge的南部部分进行的。该项目是国际合作研究（Emridge Project）的一部分，该项目是从山脊系统下方的电磁结构的详细研究中研究海洋板的生成过程的。目前的设备适合研究，因为一种仪器可以测量现场的一组电磁信号。海底设备在内，包括目前的设备是由属于东京大学海洋研究所的Hakuho-Maru安装的，并由加拿大研究船Parizeau安全恢复。