Earthquake recurrence characteristics for potential seismic zones in the southern Red Sea region and their hazard implications on Jizan city

Abstract

This study aims to quantify seismic hazard assessments in the Jazan region. For this purpose, we determined earthquake recurrence parameters for potential seismic zones that may export risk to the region. A total number of ten seismic zones were identified based on the morphotectonic nature, seismic energy pattern, and previous studies. Estimates of the b-value varied from 0.74 to 1.42, reflecting different processes of tectonic activities. The maximum possible magnitudes (Mmax) of 5.9 ± 0.3 to 8.3 ± 1.1 are anticipated to be occurred in the region between 48 and 2090 years with annual probabilities of 13%, 23%, and 36% in 25, 50, and 100 years of life, respectively. Finally, the maximum expected magnitudes obtained from this study were used in cooperation with five alternative attenuation relationships to predict peak ground accelerations. The seismic hazard map of 84% was produced at hard rock using logic tree uncertainties, showing a high seismic hazard alongside the coastline shores while a low seismic hazard extended inside the Arabian Shield that is assumed to have a stable continental crust. The response spectra at hard rock in Jizan city showed maximum PGA values corresponding to spectral frequencies of 2–5 Hz, implying that high-frequency vibrations may have an impact on building structures.

Keywords

• Recurrence parameters
• Ground motion
• Seismic hazard