【作者】 王广福； 刘福田； 徐礼国； 冉崇荣； 邵安民； 张玉云； 赵凤文；

【Author】 Wang Guangfu Liu Futian Xu Liguo Ran Chongrong Shao Anmin Zhang Yuyun Zhao Fengwen (Institute of Geophysics,Chinese Academy qf Sciences,Beijing,100101)

【机构】 中国科学院地球物理研究所；

【摘要】 OBS863-1是为研究中国大陆边缘及其海域的地壳和深部结构而研制的大动态、宽频带、三分量数字海底地震仪,它的动态范围不小于120dB,频带宽度0.05-10Hz。反馈地震计速度灵敏度5V·s/m,前置放大器放大倍率1、8、32、64四档,24位A/D变换器灵敏度10~6DC/V;采样率分15.625、31.25、62.5和125.0Hz三档,最大工作水深不小于3000m,采样率为31.25HHz时可连续记录2个月。该仪器系统是由固定在沉耦架上的仪器舱、电源舱以及海底地震观测配套设备水声释放器和定时释放器、无线电信标机、闪光灯等组成。仪器舱内安装有固定在两自由度硅油阻尼常平架上的反馈地震计、前置放大器、24位A/D变换器、PC 104机和时间服务系统;海底地震仪为自给式供电,6组6V锂电池放在电源舱中。此外,为海底地震确定方位的磁罗盘定向记录器也置于电源舱。仪器舱和电源舱之间通过水密插头实现电气连接。海底地震仪投放时,海底地震仪与沉耦架一起以0.8～1.0m/s速度自由下沉到海底,沉耦架使海底地震仪与海底介质之间获得较好的耦合。回收时,指挥船发出释放指令,水声释放器动作,海底地震仪与沉耦架脱开,并靠自身浮力以0.8m/s速度升至海面。借助无线电信标机和闪光灯(夜间)对其进行搜索。定时释放器是为水声释放器失灵时采取的补救措施。1998年夏,该仪器系统与性能与之相同的陆上用仪器在我国东海和东南沿海的浙江、福建、江西进行了海陆联合地震观测试验。更多还原

【Abstract】 OBS863-1 three-component braodband large-dynamic-range ocean bottom seismograph is developed for studying seismicity and crustal and deep earth structure in marginal sea area of Chinese continent.It has a dynamic range greater than 120db,frequency band 0.05～10Hz.The velocity sensitivity of the feedback seismometer is 5V·s/m,the amplifications of preamplifier is 1,8,32,64,sensitivity of 24-bit A/D converter 10~6DC/V,sampling rate 15.625,31.25,62.5,and 125.0 Hz selectable.The maximum working depth is not less than 3000 meters.At a sempling rate of 31.25 Hz continuous recording can last for two months. The whole system is composed of an instrument capsule and a power supply capsule,fixed to a steel anchor frame,with other matched devices for sea bottom observation,including an acoustic release a time release, a radio beacon,and strobe lights.The instrument capsule contains the feedback seismometers,which are fixed to a silicone oil damped self-leveling frame,preamplifiers,24 bit A/D converters,a PC 104 computer, and the digital clock.The instruments are powered by six sets of 6V lithium batteries placed in the power supply capsule.In addition a magnetic compass recorder for determining the orientation of the OBS is also inside the power supply capsule.The instrument capsule and power supply capsule are interconnected through water-tight cable and connectors. For deployment of the ocean bottom seismograph together with steel anchor frame sink freely down to the sea bottom at a speed of 0.8～1.0 m/s.The steel anchor frame makes a suitable coupling between the seismometer and sea bottom.On recovery a release order issued form the vessel activates the acoustic release,the seismograph is then disjointed from the frame and buoyed up at a speed of 0.8 m/s to the sea surface.It is then searched and recovered with the aid of radio beacon and strobe lights.The time release affords a supplementary means in case the acoustic release fails. This paper represents the result of a sea-land joint observation with the ocean bottom seismographs in the East Sea of China and other similar instruments on the land in Zhejiang,Jiangxi and Fujian Provinces of China.更多还原