Logn-term, Absolute Measurement of the 3 Componets of Geomagnetic Field and Establishment of Fixed Geomagnetic Stations at the Sea Floor

主要结果是，通过这项研究，我们可以总结如下： （1）一个小型3分量通量门磁铁（OBM-S5）已经开发出来。由于这个仪表是由一个电池单独安装的电池产生的，传感器外壳不会受到磁性电池的影响，并且可以继续测量更长的时间。（2）另一个Fluxgate Magnetometer （OBM-C3）哪个传感器被安装在我上面的电子元件上，以便完全消除电子元件的磁性影响。（3）用于海平面使用（OBP）的质子磁计被开发用于通量门磁计的校准。（4）开发了一种用于海底（OBE）的电磁场记录，使用深海实验以上的设备装置是在1986年8月至10月期间Izu-Bonin山脊沿平行线33 ° N的区域（约75天）。在下一年从7月到10月（78天），另一个海底实验在最后一个平行线南部的一小部分地区进行了31 ° N通过这些实验证明，通过安装的质子测量仪可以校准，通过质子测量仪的辅助。这一结果将确保在Seq地板上对3分量磁场的绝对测量的可行性。我们研究的另一个结果是1987年10月至11月在萨加米湾安装了海底观测站。这个车站是由非磁性混凝土制成的，由声学转发器制成，作为一个永久性的海洋底部平台在任何时间都可以使用。11月，Oceam底部平台被日本Matine科学和技术中心的一个专门的附属机构访问，并确认该平台的安装在良好的条件下。

Main results we have obtained through this study can be summatized as follows: (1) A small 3-component fluxgate magnetometer(OBM-S5) was developed. As this meter is deiven by a battery installed separately from the sensor housing is is not affected by the magnetization battery and can continue measurement for a longer time.(2) Another Fluxgate magnetometer (OBM-C3) whose sensor was installed about I m above the electronics was developed in order to remove the magnetic effect from the electronics components completely. (3) A proton magnetometer for sea floor use (OBP) was developed to be used for calibration of the fluxgate magnetometer. (4) An electric field recorde for the sea floor (OBE) was developed.Using the equipments mentiones above a dea floor experiment was conductod in the area of the Izu-Bonin ridge alon the parallel 33゜N from August to October 1986 (about 75 days). In the next year from July to October (78 days) another sea floor experiment was conducted in the area a little south of the last area along the parallel 31゜N Through these experiments is was proven that thr fluxgate magnetometer could be calibrated with the aid of a proton marnetometer installed nearby. This result will ensure the plausibility of making absolute measurements of 3-component magnetic field at the seq floor. Another importani result of our study is the installation of thw Ocean Bottom Observation Station in the Sagami Bay from October to November 1987. This station made of non-magnetic concrete, equipped with an acoustic transponder, works as a permanent oceam bottom platrofm reaccessible at any timw. In November the Oceam Bottom Platform was visited by a manned submersible of the Japan Matine Scienece and Technoloby Center and it was confirmed that the platform setteld in a good condition.