中国海及邻区岩石圈有效弹性厚度及其构造意义

项目名称： 中国海及邻区岩石圈有效弹性厚度及其构造意义

项目编号： No.41504017

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 天文学、地球科学

项目作者： 胡敏章

作者单位： 中国地震局地震研究所

项目金额： 21万元

中文摘要： 中国海及邻区是欧亚板块、菲律宾海板块和太平洋板块衔接地带，是地球各圈层相互作用的集中带，在全球板块构造和地球动力学研究中占有重要地位。板块构造研究的一个重要方面是岩石圈有效弹性厚度(Te)的研究，因为它反映了岩石圈长期（>1Ma）力学强度性质，与岩石圈热结构、力学结构和流变性质等密切相关。岩石圈有效弹性厚度数值成果能为岩石圈力学状态、板块动力学机制等研究提供定量依据。长期以来，由于缺乏独立于重力异常的三维海底地形模型，学者们尚未对中国海及邻区海底岩石圈有效弹性厚度展开系统研究。本项目拟根据联合船测海深和垂直重力梯度异常数据构建的最新海底地形模型（BAT_VGG），采用滑动窗口导纳技术，构建中国海及邻区1°×1°海底岩石圈有效弹性厚度模型，分析其空间分布特征，构建板块碰撞动力学模型，研究板块边缘(俯冲带)的岩石圈挠曲形变机制，为深入理解岩石圈构造动力学理论提供依据。

中文关键词： 岩石圈有效弹性厚度；重力异常；海底地形；卫星测高；导纳分析

英文摘要： The China Sea and its adjacent areas are cohesive zones of Eurasia, Philippine and Pacific plates. The plate tectonic activities are concentrated in these areas and occupy an important position in the global plate tectonic research. An important aspect of the plate tectonic research is the study of the lithospheric effective elastic thickness (Te). Te reflects the long term (>1Ma) mechanical strength of the lithosphere, and is related to the thermal structure, mechanical and rheological properties closely. It provides a quantitative basis for the research of lithospheric mechanical state and the plate dynamics mechanism. For a long time, the oceanic lithospheric effective elastic thickness of the China Sea and its adjacent areas has not been studied in details by scientists for lacking of 3D bathymetry model which is independent from gravity anomaly data. In this project, using the MWAT (Moving Window Admittance Technology) method, the bathymetry model BAT_VGG is used to construct a 1°×1° oceanic lithospheric effective elastic model of China Sea and its adjacent areas. BAT_VGG is a bathymetry model predicted from ship soundings and vertical gravity gradient anomalies. The spatial distribution characteristics of Te are studied in details. The plate collision mechanics model is constructed. Based on this model, the mechanism of flexural deformation along the subduction zones is studied deeply. These results will provide important basis for deep understanding of the dynamics of the lithosphere.

英文关键词： Lithospheric Effective Elastic Thickness;Gravity Anomaly;Bathymetry;Satellite Altimetry;Admittance Analysis