Assessing seismic site response at areas characterized by a thick buried low-velocity layer

Abstract

Earthquake ground motion is dependent on various factors, including local ground conditions. Whilst many studies have characterized the effect of having outcropping “soft” geological layers which have the ability to amplify ground motion, there is minimal literature on the effect of having such layers embedded between two harder layers. This situation creates a seismic wave velocity inversion. The Maltese islands (Central Mediterranean) present a good opportunity for the study of velocity inversion as almost half of the islands are characterized by a thick buried layer of clay. The results presented in this chapter are a combination of studies which have been conducted on the Maltese islands, using non-invasive geophysical prospecting techniques in areas characterized by a thick buried low-velocity layer, to characterize the response of earthquake ground shaking in such geological situations.