Investigating The Probabilistic Warning Times for The Earthquake Early Warning System (EEWS) On The North Tabriz Fault

In this study the first step toward establishing an earthquake early warning system in the northwestern of Iran has been studied. The area includes populated cities such an Tabriz, Ahar and Khoy. Due to heavy toll in recent years, great economic and social vulnerability of urban areas to earthquake hazards has been important and particularly noticeable. However, there has been little and few progress made in reduce and minimizing the impact of this natural and destructive disaster. While predicting the earthquake with precision is beyond our current knowledge and ability, in order to tackle the potential casualties as a result of destructive earthquakes, an Earthquake Early Warning System can significantly reduce and minimize the possible death toll. Using CDF (Probability Cumulative Distribution Function) this study aims at investigating the extent to which this Earthquake Early Warning System is implemented for the North Tabriz Fault so as to predict the time of On-Site warning time and Regional warning time in a probabilistic manner. To find out the areas and cities subject to risks of earthquakes, earthquake simulation by using stochastic method, the peak ground motion of the earth (PGA), were calculated for the cities of northwest Iran, as a result of these calculations, high- priority areas examined in the study, 15 of the top priorities in terms of seismicity on the basis of strong ground motion (PGA) nature cities such as Khoy, Varzaqan, Sarab, Tabriz, Qarah Zia od Din, Amand, Tekmeh Dash, Osku, Damirchi, Bostan abad, Sufian, Heris, Avin and Khvajeh has been considered and these cities were based of our study. The result of this study shows that the maximum Regional warning time in the cities of Khoy, Qarah Zia od Din, Avin, Bostan abad, Heris, Khvajeh, Sarab, Tekmeh Dash, Varzaqan, Damirchi, Tabriz was calculated 19, 20, 21, 13, 17, 12, 19, 14, 15, 18, 10 seconds respectively. Due to the fact that for the stations close to the epicenter of the earthquake, the creation of Regional warning time only for distant and far objects is possible and implementable; The On-Site warning time for earthquakes close to the targets was measured, as already was clear it is not possible to establish considerable On-Site warning time by for high-risk areas for North Tabriz Fault. It seems that this amount of time (Regional warning time) to set up Earthquake Early Warning Systems in the city of Tabriz where is the fourth largest city of Iran and comprises about 1.4 million inhabitants and one of the largest Iranian industrial cities that the Regional warning time is under 10 seconds, in terms of economy, cost, time and energy, according to the existing station arrangement will not be economical and vital. It has to be mentioned that the warning times were calculated using the existing seismic network geometry in the region. We calculated the warning times to at least some of the affected population and cities 15 of the top priorities in terms of seismicity on the basis of strong ground motion) in damaging and destructive earthquakes.