A Selection of GMPEs for the United Kingdom Based on Instrumental and Macroseismic Datasets

摘要

In countries with low-to-moderate seismicity, the selection of appropriate ground-motion prediction equations (GMPEs) to be used in a probabilistic seismic hazard analysis (PSHA) is a challenging step. Empirical observations of ground motion are limited, and GMPEs, when available, are generally based on stochastic simulations or adjusted empirical GMPEs from elsewhere. This article investigates the suitability of recent GMPEs to the United Kingdom. To this end, the spectral accelerations obtained from available instrumental ground-motion data in the United Kingdom with magnitude lower than 4.5 are compared with the GMPEs' predictions through the analysis of residuals and the application of statistical tests. To compensate for the scarcity of data for the magnitude range of interest in the PSHA, a macroseismic dataset is also considered. Macroseismic intensities are converted to peak ground acceleration (PGA) and statistically compared with the PGA predicted by the GMPEs. The GMPEs are then compared in terms of median ground-motion prediction through Sammon's maps to evaluate their similarities. The analyses from both datasets led to six suitable GMPEs, of which three are from the Next Generation Attenuation-West2 project, one is European, one is based mainly on a Japanese dataset, and one is a stochastic GMPE developed specifically for the United Kingdom.