A new evaluation of seismic hazard in the northwestern part of Saudi Arabia area
has been carried out, for the minimization and mitigation of earthquake losses. The study area
controlled by a number of major regional tectonic features including the Red Sea, Gulf of
Suez, and Gulf of Aqaba—Dead Sea fault system and a larger number of recorded earthquakes.
A probabilistic seismic hazard analysis is performed within a logic-tree framework.
The analysis started with an exhaustive revision of the seismic catalogues of the area and
vicinity from which a catalogue has been declustered and homogenized at moment magnitude,
Mw. According to the tectonic setting and spatial distribution of earthquakes in area and
vicinity, twelve seismic zones are defined. The seismic hazard parameters, namely the bparameter
(of the Gutenberg–Richter relation), Mmax (the upper-bound magnitude), and, k
(the annual rate of occurrence of earthquakes with minimum magnitude Mmin C 3), are
calculated for each seismic zone. The ground-motion prediction models have been selected
according to the tectonic regime associated with the earthquakes in each source zone. The
results are displayed in the form of contour maps of peak ground acceleration and five groundmotion
spectral periods for a return period of 475 years. The maximum peak ground acceleration
values are found around the Gulf of Aqaba and it is 325 gal for 475-year return period
(equivalent to 90 % probability of non-exceedance in 50 years), while the lowest values in
the eastern region is 75 gal. This is the first study developed at the northwestern part of Saudi Arabia in terms of peak ground acceleration and different spectral acceleration—SA (T). As a
result, the new generation of maps will be useful in the revision of seismic codes of the area. |
