欧亚板块运动对中国大陆岩石圈底部地幔对流速度场和水平剪切应力场的影响

发布时间：2018-05-27 22:44

本文选题：地幔对流 + 板块运动　；参考：《地学前缘》2017年05期

【摘要】：笔者建立了基于地震层析成像的热地幔对流模型,并分别计算了有、无地表板块运动约束下的中国大陆岩石圈底部的地幔对流速度场和水平剪切应力场。结果表明,欧亚板块运动速度对中国大陆地幔浅部的对流速度场影响较大,而对对流应力场的影响较小。在岩石圈底部(约100km深度),对流速度方向差异基本上达到了50%,幅度差异达到了80%以上,而地幔对流应力场的差异在方向上基本上小于10%、幅度上基本上小于20%。因此,如果仅研究岩石圈底部地幔对流应力场,则可以采用无板块速度约束的热对流模型。但如果要研究地幔浅部的对流状态和格局,则需要考虑板块运动速度。
[Abstract]:A thermal mantle convection model based on seismic tomography is established and the mantle convection velocity field and horizontal shear stress field at the bottom of the Chinese continental lithosphere without the constraints of the surface plate movement are calculated respectively. The results show that the velocity of Eurasian plate movement has a great influence on the convective velocity field in the shallow mantle of the Chinese continent, but has little effect on the convective stress field. At the bottom of the lithosphere (about 100km depth), the difference of convection velocity direction is basically 50%, the amplitude difference is more than 80%, while the difference of mantle convection stress field is basically less than 10 0 in direction and 20% in amplitude. Therefore, if we only study the convection stress field in the mantle at the bottom of the lithosphere, a thermal convection model without plate velocity constraints can be used. However, if we want to study the convection state and pattern in shallow mantle, we need to consider the velocity of plate motion.
【作者单位】：中国地震局地球物理研究所地震观测与地球物理成像重点实验室;
【基金】：科学技术部和财政部地震行业科研专项“芦山7.0级地震孕育发生机理及其影响研究”(201408014)
【分类号】：P542.5

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