A topographic effect study in the Nice region

In February 1994, eleven seismic stations were deployed in the surrounding of Nice, in order to investigate some topographic effects. Two sites, relatively homogeneous and consisting of a ridge with steep slopes on both sides were instrumented. The stations were positioned along the slopes to determine the variations of the ground motion on the ridges, slopes and foothills. The collected data were analysed using spectral ratios. The results show significant amplifications for ground motions recorded at the ridge crest. These amplifications are much stronger for the radial components but the variation in altitude does not seem to be the only factor affecting this change in ground motion, particularly for one of the two sites.