东海一菲律宾海剖面岩石层有效弹性厚度计算及分析

Lithosphere Effective Elastic Thickness Calculation and Analysis of East China Sea to Philippine Sea

摘要:

采用均衡响应函数法分段计算了自东海至东马里亚纳海盆的剖面岩石层有效弹性厚度，并利用海沟洋侧海底地形按端载加压弹性板弯曲模式对琉球海沟和马里亚纳海沟洋侧块体的弹性厚度进行了计算和对比，结合测线经过地区的地震地壳测深结果等地质、地球物理研究成果对分段计算结果进行了分析.结果表明，由均衡响应函数计算曲线多个区段可估计出2个弹性厚度值.取值大的弹性厚度，在不同区段其数值较为接近，为20~25 km，这种共性是现在热状态下海洋岩石层区域弹性特征的反映，值小的弹性厚度则是各区段内不同地质作用效果的个性反映.

关键词:东海菲律宾海剖面; 有效弹性厚度; 岩石层弹性板挠曲; 均衡响应函数

Abstract:

The isostatic response function was used to calculate the effective elastic thickness of lithosphere profile from East China Sea to East Mariana Basin.The Ryukyu trench and Mariana trench topography toward the ocean side was also used to validate elastic thickness based on the elastic plate bending model with stress load on the toe of plate,and analyzed the effective elastic thickness results of different sections in conjunction with seismic sounding,geological and geophysical research results. Results demonstrate that Two effective elastic thickness values estimated from the isostatic response function curves,large effective elastic thickness values are close,between 20~25km,the lager effective elastic thickness values reflect the regional thermal state of the marine lithosphere elastic characteristics.The smaller effective elastic thickness values reflect the geological process characteristics of different sections.

Key words:East China Sea to Philippine Sea profile; Effective elastic thickness; Elastic plate flexure; Isostatic response function