Site-specific earthquake ground motion parameters at the southeastern part of Muscat, Sultanate of Oman

Abstract

The site-specific earthquake ground motion parameters were presented for the southeastern part of Muscat governorate, including amplification factor at different periods and the values of PGA and spectral accelerations at the surface. The study starts with assessment of the seismic hazard at bedrock level using the probabilistic approach. This assessment was preformed considering an updated earthquake catalogue. The outputs of the probabilistic seismic hazard were uniform hazard spectra for return periods of 475,975 and 2475 years. Spectral matching technique was applied to define the compatible ground motion time series based on the outputs of the probabilistic approach and the deaggregation process. The representative's dynamic soil profiles were determined using the in-situ measurements of compressional and shear waves. The effects of soil deposits on the propagated ground motions time series was evaluated using the equivalent linear analysis in the frequency domain. The final results clarified that, the fundamental site period at the middle coastal parts of the area has the largest values (0.2–0.276 s). The maximum amplification factors found to be 2.76, 2.36, and 2.8 for the periods of PGA, 0.1 s, and 0.2 s, respectively. The values of PGA and spectral accelerations at the surface level are also provided.