Developlment of super-deep instrumental housings.

地球上最深的部分位于北太平洋西部。通常海洋仪器的能力深度被限制在600米以下，然而，对日本科学家来说，这个深度显然是不够的。在本研究项目中，我们研制了用于水深大于12公里的钛缸式声释放和钛壳式水流计，通过窄波束定向换能器模式改善了声释放的声学特性，并实现了超过12公里的信号传输能力，钛壳式水流计已被证明适用于水深大于12公里的水流计。系泊部署于1987年1月28日进行，并于1987年5月回收。104天的连续电流记录表明，惯性振荡在底层增加。在伊豆-小笠原海沟9205 m深度的研究中，首次显示出最大电流速度大于10 /秒。

Deepest poritions over the earth are located in the western Notrh Pacific. Usually capcbilty depth of oceanic instruments in limited to be less than 600 m, however, the depth is obviously not enough for Japanese scientist. In this research project, we dovolopod we have developed instrumental nousings for depth greater then 12 km water by using titanium cylinder We developed acoustic release and current meter with titanium housing Acoustic characteristics of the release is improved by a narrow beam transducer pattern of directional, and has been proced the capability of more than 12 km signal transmission, A current meter with titanium housing has been proved to applicapable for a depth greater than 12 km. Deployments of the mooring was made on Jamary 28, and recoveres on mayll,1987. A 104 day long continuous record of current shows that inertial oscilation is increased at bottom layer. A mazimum current speed is greater than 10 cn/sec, which is first shown by the research for the depth of 9205 m in the Izu-Ogasawara Trench.