2011年日本东北大地震对中国东部地壳形变场的影响

The Impact of the Great 2011 Tohoku-Oki Earthquake on Crustal Deformation in Eastern China

2011年日本东北M W 9.0大地震不仅造成日本境内地表产生超过5 m的同震位移和显著的震后变形,在中国大陆东部地区也引起明显的远场同震及震后变形。本文利用1999~2017年GPS连续站和流动站观测资料,计算高空间分辨率的远场同震和震后变形位移场。结果表明,2011年日本东北M W9.0地震对中国105°E以东区域产生了E向运动的同震变形,对中国东北和山东半岛产生了可观的震后变形,且GPS震后变形的累积量已超过相应台站的同震位移量。利用日本大地震在中国东部地区产生的远场同震和震后变形位移场,可为维护区域大地参考基准和反演岩石圈及上地幔的流变性质提供定量约束。

The 2011 Tohoku-Oki M W 9.0 earthquake not only caused more than 5 m coseismic displacement and significant post earthquake deformation of the surface in Japan,but also caused significant far-field coseismic and post earthquake deformation in the eastern part of Chinese mainland.In this paper,using intensive GPS data observed from 1999 to 2017,we infer the results of far-field coseismic and postseismic displacements with high spatial resolution in eastern China.The results show that the 2011 Tohoku-Oki earthquake produced coseismic deformation of eastward movement in the east of 105°E in China,and considerable postseismic deformation in northeastern China and Shandong peninsula.The accumulated GPS postseismic displacement has exceeded its coseismic displacement.The observed far-field coseismic and postseismic deformation are helpful to maintain regional geodetic datum,and to provide a priori constraints for investigating the lithosphere and upper mantle rheology.