上海平野で観測された微動記録からレイリー波を分離する試み

Abstract

In order to examine the applicability of microtremors to studying ground vibrational characteristics and understanding of subsurface structures, we separate Rayleigh waves from observed microtremors. For this study, we use the array data of microtremors observed in the Shanghai plain in 1993; this observation was carried out as a part of joint research project with State Laboratory for Disaster Reduction in Civil Engineering, Tongji University, China. In order to ensure the accuracy of the following analysis, at first, the directions of wave propagation are carefully determined using the two-dimensional slowness analysis. On the basis of this result, the phase velocities are calculated with cross-correlation. And then wave groups whose phase velocities were determined accurately are identified with Rayleigh waves using particle motion diagrams.