Assessment of seismic hazards in Yemen

The seismic hazard analyses for Yemen have attracted the attention of researchers during the last two decades. However, the studies are limited and mainly use deterministic or approximate conventional probabilistic approaches. The conclusions drawn from these studies do not fit with current seismic design codes (International Building Code). This article presented the method and findings of a probabilistic seismic hazard assessment for Yemen in accordance with current seismic design building regulations. All the data sources, available nationally and internationally, were utilized in compiling earthquake database by covering the recent records and the seismic activity maps of the study region. The study area was regionalized to 11 seismotectonic area sources on the basis of the seismicity maps and available tectonic maps. On the analytical side, the earthquake recurrence analysis was evaluated for each source, and logic tree concept was used to model the seismic sources that may have significant effect on seismic hazard evaluation of Yemen as a combination of area and line sources. A probabilistic forecasting model was formulated, appropriate ground motion attenuation relationships were used, and seismic hazard contour maps were developed for the entire Yemen area. The maps present dense contours of peak ground accelerations and short and long period spectral accelerations for different return periods. The highest predicted seismic hazard is found in Dhamar City. This study provides basic and essential requirements that will be valuable in developing advanced seismic design criteria for Yemen.