View article

A critical component in the interpretation of earthquake ground motions is the role that site effects play. In eastern Canada, the sediment layers which overlie glaciated bedrock produce strong and highly variable site responses. We use horizontal‐to‐vertical (H/V) response spectral ratios as the indicator variable by which to characterize the salient characteristics of site response. We show that site response can be modeled using two key descriptive variables that are readily obtainable: (1) peak frequency (f_peak), as determined from H/V or sediment depth; and (2) overall sediment type (or stiffness). We use these variables to create a preliminary model of site amplification that can be used in the development of ground‐motion prediction equations (GMPEs) and in regional‐scale ShakeMap‐type applications.

The key to the site characterization is the relationship between f_peak and sediment thickness (depth …