珍贝—黄岩海山链热-重力均衡动态调节机制  

Thermal-gravity equilibrium adjustment mechanism of Zhenbei-Huangyan seamount chain

作　　者：于磊[1,2] 张健[1,2] 陈石[3] 董淼[1,2] 徐长仪 

机构地区：[1]中国科学院计算地球动力学重点实验室,中国北京100049 [2]中国科学院大学地球科学学院,中国北京100049 [3]中国地震局地球物理研究所,中国北京100081

出　　处：《地震学报》2015年第4期565-574,711,共10页Acta Seismologica Sinica

基　　金：国家自然科学基金项目(41174085);国家自然科学基金重点项目(41430319);中国科学院创新团队项目(KZZD-EW-TZ-19);中国科学院战略性先导科技专项(XDA1103010102)共同资助

摘　　要：珍贝—黄岩海山链作为我国南海的残留扩张中心,对其研究具有重要的科学意义.本文运用均衡学方法,通过重力异常数据反演了过珍贝—黄岩海山链剖面的地壳界面变化,同时计算了岩石圈热结构状态,在此基础上建立了珍贝—黄岩海山链的岩石圈地温结构模型.通过均衡分析方法,对剖面上测点的海底地形数据进行了热均衡和重力均衡分析,得到了热均衡和重力均衡形变量.结果表明,在珍贝—黄岩海山链高热流区域,热均衡作用可以产生最大约0.55km的形变,其重力均衡形变范围为0.77—1.89km.热均衡通过改变海底地形和地壳物质密度不断作用于重力均衡,重力又反过来作用于热均衡,形成了热均衡-重力均衡动态调节机制.During the processing of isostatic gravity anomaly analysis,it was pointed that the isostatic correction of the South China Sea was not completely, especially in Zhenbei-Huangyan seamount chain.No reasonable explanation for this phenomenon has been proposed until now,and seamounts compensation mechanism remains unresolved.It is feasible and necessary to conduct the dynamic equilibrium research in this region.We combine the thermal and gravi-metric method to evaluate crustal density structure so as to establish the litho-spheric thermal structure of Zhenbei-Huangyan seamount chain based on the observed free-air gravity anomaly data. And then we analyze the thermal equi- librium and the gravity equilibrium effects based on the submarine topography data by adopting the standardized equilibrium technology. The results show that in the high heat flow region of Zhenbei-Huangyan seamount chain, the deformation induced by the thermal equilibrium is up to 0. 55 km and the deformation due to the gravity is from 0.77 to 1.89 km. As a long-term adiust- ment factor, the thermal equilibrium constantly affects the gravity equilibrium by changing submarine topography and crustal material density, and gravity acts on geothermal equilibrium in turn at the same time, so the dynamic adjust-ment mechanism generates.

关 键 词：珍贝-黄岩海山链 岩石圈 热均衡 重力均衡 

分 类 号：P314.2[天文地球—固体地球物理学] P312.3[天文地球—地球物理学]