SEISMICITY PARAMETERS OF THE AUGUST ۱۷, ۱۹۹۹IZMIT EARTHQUAKE IN NORTHERN TURKEY AND THEFEBRUARY ۶, ۲۰۲۳ EARTHQUAKE IN SOUTHERNTURKEY-NORTHERN SYRIA

In this article, an attempt has been made to calculate and compare the seismicity parameters of twovery destructive earthquakes in Turkey, which are the deadliest earthquakes in the last twenty-fiveyears of the Anatolian Plateau. The first earthquake occurred due to the activity of the North AnatolianFault Zone (NAFZ) on August ۱۷, ۱۹۹۹ with a magnitude of ۷.۸ in the northwest of Izmit city. Thesecond one occurred on February ۶, ۲۰۲۳ with the same magnitude due to the activity of the EasternAnatolian Fault Zone (EAFZ) in southeastern Turkey and northern Syria. In this study, the seismicityparameters including a and b-value, and Mc have been calculated as a function of time for a period of۵ years around both fault systems before the occurrence of two destructive earthquakes. Examining theresults shows sharp increase in the b-value, a few months before both large earthquakes. This confirmsthat online monitoring of b-value can be useful as a precursor for warning before large earthquakes

کلیدواژه ها:

Izmit ، b-Value ، North and East Anatolian Fault Zones ، Turkey-Syria Earthquake