华北地区2009～2013年地下物质密度变化及其地壳运动含义

Subsurface Density Change in North China from 2009 to 2013 and Its Implication on Crustal Movements

基于华北地区2009~2013年半年尺度重力复测资料,利用扣除半年和年周期获得的重力年变率反演计算华北地区地下物质密度变化。结果显示,华北地区总体上呈现东、西两侧的山西地区和渤海湾盆地为负变化,中间地带的华北平原表现为正变化,揭示了华北平原中下地壳因两侧膨胀和岩石圈热物质上涌而使物质处于压缩状态。

The gravity change rate（GCR）,which is derived from repeated gravity data deducted the semi-annual and annual changes of the network of the north China,is used to inverse subsurfacial density change.The results show that the subsurfacial density change trends from negative（Shanxi region）,to positive（north China plain）,to negative（Bohai bay basin）,from west to east.It reveals that the middle and lower crust are in the compressed state caused by the extension of the Shanxi rift and the Bohai bay basin and the upwelling of the lithospheric hot material.