There are some interesting links to Japanese data on the Tohoku earthquake from Tolyo University. One is:
The comparison of long-period ground motion: The feature of seismic ground motion in city center and influence by architectural structure (By:Dr.Furumura and Dr.Takemura)
A velocity response spectrum is calculated according to waveform recorded at Earthquake Research Institute in Bunkyou-ku district. The figure shows comparison with that of Niigata Chuetsu earthquake in 2004. The Chuetsu earthquake had strong long-period ground motion with period of 7 second, which causes only a minor damage mainly among skyscraper buildings. The 2011 Tohoku earthquake has about the same strength of velocity response occurred in a wide periodic band from 0.5 to 20 second. Not only skyscrapers but also all kind of buildings from wooden building (below 0.5 second) to a low-slung building (around 1second) and skyscraper buildings (few second).