Plate Dynamics at the Eastern Margin of the Japan Sea from Long-term Seafloors Observation.

来自长期海底观测的日本海东缘板块动力学。

基本信息

批准号：
63420055
负责人：
SUYEHIRO Kiyoshi
金额：
$ 1.98万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (A)
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1989
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-63420055/
关键词：
Downhole seismometer Brood-band seismometer Ocean Drilling Program Japan Sea 海底孔円地震計

项目摘要

The Japan Sea constitutes a back arc in the northern Japan plate subduction zone. How the subducting Pacific plate interacts with the overriding plate and the surrounding upper mantle is still not fully understood. This is partly due to the lack of key observational data from the surrounding deep seafloors. We have developed and emplaced a digital broadband seismometer in an ODP hole about 160 km west off NE Japan from the D/V JOIDES Resolution in Sep., 1989, in order to initiate a long-term seismic observation.Hole 794D is 733.5 m deep below seafloor (water depth: 2818 m). The borehole package including a 3-component feed-back type accelerometer and a digital data telemetry system was clamped near the bottom within solid basalt. The sensor is a ruggedized version of Guralp CMG-3 with leveling mechanisms for horizontal sensors. The seismic data are sent uphole in two gains at a rate of 80 Hz/ch, 16-bit each via the 7-conductor logging cable. A controlled source seismic experiment was carried out on R/V Tansei-maru for two days while recording the borehole data on the drill ship real-time. Then, the seafloor long-term seismic recording system including a battery package (24V-38AH x 20) and glass sphere buoys with an acoustic transponder attached to the end of a 6000 m rope was deployed from another vessel. The system can record 60 MB of data by time window/event trigger algorithms. Thus we believe we have initiated a broadband long-term seismic observation for the first time in a marine environment.

日本海构成了北部日本板块俯冲带的背弧。俯冲的太平洋板如何与覆盖板和周围的上地幔相互作用。这部分是由于缺乏来自周围深海地板的关键观察数据。我们已经在1989年9月的D/V加入分辨率的日本向西约160公里的ODP孔中开发并扩展了数字宽带地震仪，以启动长期的地震观测。HOLE794D在Seafloor（水深：2818 m）深处733.5 m。钻孔套件，包括3组分后馈型加速度计和数字数据遥测系统，在固体玄武岩内的底部附近夹紧。该传感器是Guralp CMG-3的坚固版本，具有水平传感器的平整机制。地震数据以80 Hz/ch的速度以两种收益发送，每条通过7导电仪记录电缆各有16位。在R/V Tansei-Maru上进行了两天，同时记录了实时的钻孔数据，在R/V Tansei-Maru上进行了一个受控的源地震实验。然后，从另一只容器中部署了海底的长期地震记录系统，包括电池套件（24V-38AH x 20）和玻璃球体浮标，并带有一个附着在6000 M绳索末端的声音应答器。该系统可以通过时间窗口/事件触发算法记录60 MB的数据。因此，我们认为我们在海洋环境中首次启动了宽带长期的地震观察。