Statistical Analysis of Rotational Components in Wenchuan Earthquake Near field Region

Abstract:

The seismic records of 25 stations at the sites of Class Ⅰ,Ⅱ and Ⅲ in Wenchuan were selected. Their tilt and torsional components were calculated and statistically analyzed according to the relationship between translation and rotational components. The results show that the correlation between translation and rotational components is robust; if the peaks of translation component are the same, the rocking component is larger in softer site; the torsional component is half of the translational component; the attenuation of rotational component is slow.

Key words:site classification; tile components; torsional components; attenuation relationship