Probabilistic Seismic Hazard Analysis for Harrat Madinah, Saudi Arabia Using Regional Ground Motion Prediction Equations

Ryota Kiuchi, Walter D. Mooney, & Hani M. Zahran

Published August 10, 2018, SCEC Contribution #8370, 2018 SCEC Annual Meeting Poster #027

We present Probabilistic Seismic Hazard Analysis (PSHA) associated with future volcanic activity in Harrat (volcanic lava field) Madinah, Saudi Arabia using region-specific GMPEs. Harrat Madinah, which located in northwestern part of the Arabian Peninsula, has experienced two known seismic episodes: (1) a precursor seismic swarm to a historical eruption in 1256 CE, and (2) a 1999 seismic swarm in the subsurface (20-40 km). We evaluated three different scenarios M 6, 6.5, 7 as the maximum magnitude of the future event to accompanied any future volcanic eruption. The location of the largest event is assumed to correspond to the calculated spatial probability of vent opening (Dietterich et al., 2017). The background seismicity related to this mainshock is also taken into account for PSHA by applying Gutenberg-Richter (G-R) magnitude-frequency relation. The new region-specific GMPEs used in this analysis developed by revising the model of Boore et al. (2014) as reference GMPEs. This revision was accomplished using selected records of PGA and PGV from 177 earthquakes with magnitude 3.0 – 5.4 that have occurred in Saudi Arabia. In this revision of the reference GMPEs, smaller magnitude scaling and lower anelastic attenuation are incorporated to yield the updated region-specific GMPEs. The PSHA derived by the region-specific GMPEs, assuming M 6.5 as the largest event, indicate ground motions of up to 0.25 g of PGA for 2 % probability of exceedance in 50 years.

Key Words
PSHA, GMPE, Saudi Arabia

Citation
Kiuchi, R., Mooney, W. D., & Zahran, H. M. (2018, 08). Probabilistic Seismic Hazard Analysis for Harrat Madinah, Saudi Arabia Using Regional Ground Motion Prediction Equations. Poster Presentation at 2018 SCEC Annual Meeting.

Related Projects & Working Groups
Ground Motions