JOURNAL OF THE BALKAN GEOPHYSICAL SOCIETY, Vol. 2, No 4, November 1999, p. 90-99, 3 figs.

An application of the semi-Markov model

for earthquake occurrences in North Anatolia, Turkey

Yildiz Altinok* and Demir Kolcak*

* Istanbul University, Engineering Faculty, Geophysical Engineering Department, 34850 Avcilar , Istanbul, Turkey

( Received 7 July 1999; accepted 15 October 1999 )

Abstract: Earthquake occurrence probabilities are estimated by applying the Semi-Markov Model. This model assumes that the successive earthquakes in the same structural discontinuity are not independent events, but they are influenced by the elapsed time interval between them. The North Anatolian Fault Zone between longitudes 26.00O E and 42.00O E is selected for this study. Seventy-one earthquakes having surface wave magnitudes M5.5 occurred in the region between 1902 and 1992 are considered. The occurrence probabilities were obtained by determining interval transition probabilities for region to region and magnitude to magnitude transitions of these earthquakes. The determination of joint probabilities demonstrates that earthquake occurrence can be investigated in the three dimensions of space, time and magnitude.

Key Words: Earthquake Occurrence, Semi-Markov Model, State Transition , Holding Time, Interval Transition Probability, North Anatolian Fault Zone.