Assessment of Seismic Hazard in Yemen

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