Generation and propagation of static displacement estimated using KiK-net recordings

Using KiK-net strong-motion data recorded at eleven stations during the 2011 off the Pacific coast of Tohoku Earthquake (the 2011 Tohoku Earthquake), we investigate the generation and propagation of static displacements, i.e. coseismic permanent near-field displacements. The static displacements are calculated by double numerical integration after removing acceleration steps from the acceleration signals. The estimated static displacements are totally in agreement with the land deformation measured by GEONET, the GPS network established by the Geographical Survey Institute, despite the fact that our estimation method is extremely simple. It is hoped that scientific studies of this disastrous earthquake will one day lead to a real-time evaluation system for static displacement using strong-motion data. This would be expected to greatly improve the effectiveness of tsunami alert systems, since tsunamis are caused by sea-floor movements during earthquakes.