权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Comprehensive Study on Ocean Floor Dynamics

洋底动力学综合研究

基本信息

批准号：
11204101
负责人：
TOKUYAMA Hidekazu
金额：
$ 81.28万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research on Priority Areas
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2005
项目状态：
已结题

项目摘要

Ocean floor controls an emission of heat and mass from the interior part of the Earth, in particular from mantle. And, ocean acts as a reservoir of mass flux in earth system in a sense, suggesting that the Earth is related to the circulation of mass in the upper part of the Earth.It is well known that history of dynamic earth system has been recorded in deep ocean floor sediments since last 150Ma. Therefore, decoding of the record will provide us new information that creates new paradigm of earth science.In order to develop deep ocean floor science, we need core drilling samples recovered from deep sea as the first step. The second step is characterized by geochemical and geophysical analysis including age determination. The third is in situ geophysical and geochemical measurement in borehole. Finally, we set up long-term borehole observatory in order to monitor ongoing dynamic change of the Earth interior.Our research group is composed following five subgroups such as comprehensive ocean floor dynamics subgroup, subduction zone subgroup, oceanic plateau and mantle plume subgroup, methane hydrate subgroup, and deep biosphere /evolution of life group.The results of our research are listed as follows.1) New scenario regarding to the process of methane hydrate formation, dissociation, and concentration is proposed2) Extremely warm climate and mass extinction of life are closely related to dissociation of methane hydrate3) Millennium scale environmental change is induced by thermal and dynamic impact resulting from outside of globe4) Surface global environmental change is associated with plate dynamics5) Global seismic network using borehole is constructed6) New findings are acquired in both fields of ecosystem of bacteria in deep crust and circulation of surface mass of the Earth

洋底控制着地球内部，特别是地幔的热量和质量的释放。海洋在某种意义上是地球系统中物质通量的储存库，表明地球与地球上部的物质循环有关。众所周知，地球动力系统的历史从近150 Ma以来一直被记录在深海海底沉积物中。因此，对记录的解码将为我们提供新的信息，创造地球科学的新范式。为了发展深海海底科学，我们需要从深海中提取岩心钻探样本作为第一步。第二步的特点是进行地球化学和地球物理分析，包括年龄测定。三是井下现场物化探测量。本课题组由综合海底动力学亚群、俯冲带亚群、大洋高原与地幔热柱亚群、甲烷水合物亚群、深部生物圈/生命演化亚群五个亚群组成。研究成果如下：1)关于甲烷水合物形成、解离、演化过程的新设想2)极端温暖的气候和生命的大量灭绝与甲烷水合物的解离密切相关3)千年尺度的环境变化是由地球外部的热力和动力影响引起的4)地表全球环境变化与板块动力学有关5)利用钻孔构建全球地震台网6)在地壳深部细菌生态系统和地球表面质量循环两个领域都有了新的发现