利用Moho地形导纳法(MDDF)反演中国大陆岩石圈有效弹性厚度

Effective elastic thickness of continental lithosphere in China with Moho topography admittance method

本文用数值实验方法验证了,在Moho地形导纳法(MDDF)中使用先由重力数据反演的Moho面相对起伏数据,能较传统的重力地形导纳法获得更高的反演精度.之后作者应用Moho地形导纳法(MDDF)反演获得了精度较高的中国大陆区域岩石圈有效弹性厚度.结果显示:(1)中国地区岩石圈有效弹性厚度Te从东向西大体上呈阶梯状上升;(2)Te与岩石圈地震-热厚度、地表热流、上地幔顶部的地震波速度等数据密切相关;(3)在中国中东部,Te较低的区域以及Te的高低值转换带对应较强的地震活动性.但在西部,Te与地震活动性的相关性并不明显.

The accuracy of the inversed elastic thickness of the lithosphere is fairly low wltla the conventional spectral method. We verified that using the Moho relief from gravity anomaly inversion in the Moho-topography admittance method can improve the inversion accuracy of Te greatly compared to conventional gravity-topography admittance method. Then we calculated Te in certain area of China with Moho-topography admittance method. The inversion results indicate that （1） Te in China increases stepwise from east to west on the whole, （2） Te is closely related to the lithosphere thickness, surface heat flow, seismic wave velocity in the uppermost mantle, and （3） while seismicity is more concentrated in areas where To is low or at boundaries between high and low To in central and eastern China, it does not show this relationship with To in western China.