Assessment of the seismic hazard constitutes the main input for the design of structures to resist the effects of earthquakes. This assessment is conducted in the probabilistic sense to provide peak ground motion parameters associated with specific annual probabilities of exceedance or average return periods as stipulated in the contemporary earthquake resistant design codes. Previous quantification of seismic hazard in Dubai are controversial with peak ground acceleration values associated with 475-year return periods varying between 0.28g and 0.04g (1g equals to the acceleration due to gravity = 9.8 m/s2). Probabilistic earthquake hazard assessment entails the association of earthquake epicenters with tectonic entities (source zones Figure 1) and the statistics of earthquake occurrence in these source zones, Figure 2 and Table 1. In addition the attenuation relationships, which describe the decrease of the ground motion amplitude with distance from source, and the stochastic model for the prediction of future earthquakes, need to be determined.
The kinematics of the region where Dubai is located controlled by the collision between the Arabian Plate and the Eurasian Plate, producing the Zagros collision zone and the Makran subduction zone. The kinematics includes three ridge areas: the Red Sea Rift, the Gulf of Aden and the Owen Fracture Zone. The most significant large-to-great size earthquakes in the region occur in the Zagros Belt and the Makran Subduction. Their closest approach to Dubai are respectively at 140km and 220km. Earthquakes of small-to-medium size (magnitudes 4-5.5) can occur at Dibba Fault at Masafi at a distance of about 110km from Dubai. As such, the earthquake hazard in Dubai is essentially controlled by large-to-great size distant earthquakes.
Probabilistic hazard assessment results for Dubai provide peak ground acceleration levels in units of g that correspond to 50% probability of exceedence in 50 years (Average return period of 72 years, Figure 3), and Peak Ground Acceleration in units of g that correspond to 10% probability of exceedence in 50 years (Average return period of 475 years, Figure 4) of 0.054g in Dubai at the engineering bedrock and Peak Ground Acceleration in units of g that correspond to 2% probability of exceedence in 50 years (Average return period of 2475 years, Figure 5)
The deterministic hazard assessments based on maximum earthquakes taking place in the source zones also verifies this level. At 72-year and 2475-year return periods the peak ground acceleration levels are respectively 0.032g and 0.076g (Figures 6, 7 and 8).