Probabilistic and stochastic seismic hazard assessment for wind turbine tower sites in Zafarana Wind Farm, Gulf of Suez, Egypt

Abstract

In this study, stochastic and probabilistic seismic hazard procedures are used to estimate the seismic hazard for wind turbine tower sites in Zafarana Wind Farm, Gulf of Suez, Egypt. The seismic activity in and around the study area, which includes many active fault systems along the Gulf of Suez resulting in many moderate and strong earthquakes, has been well described. These earthquakes result in major stress drops in the Eastern desert and Gulf of Suez area. These recent findings have helped to reshape the seismotectonic environment of the Gulf of Suez area, which is a perplexing tectonic domain. Based on the new information and data collected, the seismic hazard for the Gulf of Suez region, particularly the wind turbine towers in Zafarana Wind Farm and its vicinity, was reexamined using probabilistic and stochastic approaches. Alternate seismic source and magnitude-frequency relations combined with various indigenous and “foreign” attenuation relationships were adopted within a logic tree formulation to quantify and project the regional exposure on a set of hazard maps. The hazard maps showed the peak horizontal ground acceleration and spectral acceleration at PGA, 0.1, 2.0 and 4.0 s. These acceleration levels were computed for 20 and 10 % probabilities of being exceeded in 50 years. Finally, the 0.5, 1, 5, 10 and 20 % damping median response spectra are provided for wind turbine towers in Zafarana Wind Farm site based upon a stochastic simulation technique and on borrowed attenuation relationships.