Developing ground motion prediction equations for western Saudi Arabia using an adjustment of a reference model

Ryota Kiuchi, Walter D. Mooney, James Mori, Hani M. Zahran, Wael AlRaddadi, & Salah Youssef

Published August 15, 2017, SCEC Contribution #7722, 2017 SCEC Annual Meeting Poster #266

There are several active seismic zones around Saudi Arabia, including the Red Sea and the Gulf of Aqaba where a destructive magnitude 7.3 event occurred in 1995 (Mohamad et al., 2000). The recently deployed dense seismic network organized by the Saudi Geological Survey (SGS) has made it possible to detect multiple seismic swarms beneath the volcanic fields in western Saudi Arabia as well as monitor seismic activity throughout the Arabian plate more accurately. The most recent damaging event was a M5.7 earthquake that occurred in 2009 at Harrat Lunayyir, in western-central Saudi Arabia. In terms of seismic hazard assessment, Zahran et al. (2015; 2016) present Probabilistic Seismic Hazard Assessments (PSHA) for western Saudi Arabia that were developed using published Ground Motion Prediction Equations (GMPEs) from areas outside of Saudi Arabia.

To develop the GMPEs appropriate for western Saudi Arabia, we considered 41 earthquakes of M 3.0 – 5.4, recorded by 124 stations of the SGS network. We selected a set of 442 peak ground acceleration (PGA) and peak ground velocity (PGV) records with a range of epicentral distances from 3 km to 400 km. Most of the events in our dataset occurred during the 2009 Harrat Lunayyir seismic swarm, and some of the events occurred in the Red Sea and the Gulf of Aqaba. We used the GMPEs model known as BSSA14 (Boore et al., 2014) as a reference model to estimate our own best-fitting coefficients from a regression analysis for western Saudi Arabia. For epicentral distances less than 50 km, our best fitting model has the different seismic moment scaling in comparison with the GMPEs of BSSA14 adjusted for the California region. Furthermore, our model shows that the peak amplitudes clearly have less attenuation in western Saudi Arabia than in California, which is in agreement with the geologic setting.

Key Words
GMPEs, Ground Motion, Saudi Arabia

Citation
Kiuchi, R., Mooney, W. D., Mori, J., Zahran, H. M., AlRaddadi, W., & Youssef, S. (2017, 08). Developing ground motion prediction equations for western Saudi Arabia using an adjustment of a reference model. Poster Presentation at 2017 SCEC Annual Meeting.

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