深海6000 m拖曳式瞬变电磁系统及其应用  

Marine towed transient electromagnetic system working in deep-sea below 6000 meters and its application

作　　者：周胜[1,2] 宋刚 黄龙 席振铢[1] 侯海涛 陈兴朋[2] 亓庆新[2] 

机构地区：[1]中南大学地球科学与信息物理学院,长沙410083 [2]湖南五维地质科技有限公司,长沙410205

出　　处：《地球物理学报》2017年第11期4294-4301,共8页Chinese Journal of Geophysics

基　　金：国家重点研发计划"深海关键技术与装备"重点专项(2016YFC0303100);深圳市未来产业发展专项(HYZDFC20140801010002);海南省科技兴海专项(2015XH07)资助

摘　　要：针对我国西南印度洋合同区热液硫化物矿快速、有效以及便捷地质勘探装备的要求,研发了由甲板控制系统、万米光电复合缆、仪器舱拖体和天线拖体组成的深海6000 m拖曳式瞬变电磁系统.为了便于拖体布放和快速发现异常,选择重叠回线收发装置类型;采用理论数值计算确定了在拖曳高度不大于50 m的前提下,观测1～100ms窗范围内的二次场响应,可以发现近海底深海热液硫化物矿堆;另外,通过不同拖延深度海上试验,研究了拖曳深度对瞬变电磁的影响规律及仪器性能.大洋第30航次第二航段在西南印度洋脊热液区,应用该系统发现了明显的瞬变电磁异常.印证了系统的有效性.Aiming at the requirements of fast, effective and convenient detection of the hydrothermal sulfide ore in the contract area of the Southwest Indian Ocean, we have developed a towed transient electromagnetic system working in deep-sea below 6000 meters. The system consists of deck control system, ten thousand meters photoelectric composite cable, instrument cabin and antenna cabin. To release towed body conveniently and find anomaly response quickly, coincident loop is applied. Theoretical numerical calculation results show that the abnormal response of the near seafloor hydrothermal sulfide deposit appears during the delay time of 1~100 ms when the towed height is no larger than 50m. In addition, the influence of the towing depth on the transient electromagnetic field and the performance of the instrument are studied by experiments. Finally, anomaly response of a typical hydrothermal sulfide ore was found by using this system, in the hydrothermal area of the southwest Indian Ocean Ridge, and in the second leg of China＇s 30th ocean exploration voyage.

关 键 词：深海瞬变电磁 观测装置 观测时窗 拖曳高度 热液硫化物矿 

分 类 号：P319[天文地球—固体地球物理学] P631[天文地球—地球物理学]