国产I-4C型OBS在西南印度洋中脊的试验

Abstract

介绍了在DY115-21航次第6航段西南印度洋中脊构造调查中,中国科学院地质与地球物理研究所研制的5台I-4C型海底地震仪(OBS)的试验情况.在不同的水深点(2370～3534m)共投放OBS 6个台次,全部投放和回收成功.OBS内置电化学式和外置机械式两种上浮释放系统都成功动作,取得了船载气枪震源的地震数据.但仍存在三个主要问题:第一,上浮后的GPS应答搜寻系统无效果;第二,夜间回收时所需的灯光明亮度较差;第三,外在结构不利于海面上的姿态控制和打捞.

Five I-4C type broad band ocean bottom seismometer (OBS) made by the Institute of Geology and Geophysics, CAS together with other OBSs were used in the survey of Southwest India Ridge during the sixth section of DY115-21 cruise. This paper describes in detail the experiment process of the five I-4C type broad band OBS. These five OBS were deployed 6 times in various water depth sites(2370-3534 m) and all recovered successfully. The inner electrical and chemical releasing system and the extra added mechanical releasing system both operated successfully. Seismic data of mid ridge produced by air gun array was recored. But the experiment showed this type OBS still exists some faults as follows. (1) The GPS locating and receiving system used for seeking floated OBS on sea surface was invalid; (2) The light from OBS was too weak to seek floated OBS during night; (3) The outer structure of OBS was not convenient for cathing OBS from water due to its bad floating pose.