Comprehensive studies for the 2011 off the Pacific coast of Tohoku earthquake

2011年3月11日发生在日本东北地区近海的2011年东北太平洋沿岸大地震，持续时间长的大地面运动和巨大的海啸给人类社会带来了巨大的破坏。为了弄清这次大地震的发生机制，我们进行了各种观测。海洋和陆地的地震观测揭示了地震活动在时间和空间上的变化。通过地震勘测和洋底地壳运动测量来估计震源的几何形状。此外，在主震期间的滑动分布得到了使用各种地球物理数据集。实地调查揭示了海啸的发生，并对海啸的生成过程进行了估算。同时，也明确了建筑物的破坏情况，为今后的减灾工作提供了有用的信息。

The 2011 off the Pacific coast of Tohoku earthquake occurred offshore of northeast Japan region on March 11, 2011, and large ground motion with long duration and huge tsunami damaged human society. To clarify the generation mechanism of this large earthquake, we carried out various observations. Seismic observations in marine and land areas revealed variation of seismic activities in time and space. Geometry of the source was estimated by seismic surveys and ocean bottom crustal movement measurements. In addition, the slip distribution during the mainshock was obtained using various geophysical datasets. Field surveys revealed tsunamis and the generation process of the tsunamis was estimated. Damage of constructions was also clarified and useful information for disaster mitigation in future was obtained.