Seismic hazard map of Turkey using the deterministic approach

Because the instrumental records of Turkey are far from being satisfactory for modeling the seismic hazard using the probabilistic approach, an attempt was made in this study to accomplish it through the deterministic way. In this regard, all active faults of Turkey, small and large, were evaluated together to obtain major fault systems. Then, the procedure suggested by Wells and Coppersmith [Bull. Seismol. Soc, Am. 4 (1994) 975] applied to those faults to obtain the maximum magnitude earthquake that they can generate. To do this, it was assumed that 1/3 of the total fault length would rupture to yield the maximum earthquake. Following that, seven different attenuation relationships of the strong ground motion were utilized to calculate the maximum horizontal ground accelerations for the whole Turkey at 0.2degrees intervals using the computer model TUMDES written in BASIC programming language. The computed peak ground acceleration (pga) values were contoured and the iso-acceleration map based on Sadigh et al. [Seismol. Res. Lett. 1 (1997) 180] relationship was selected as the new seismic hazard map of Turkey on which the seismic zonations were determined as following: pga>0.3 g Zone 1; 0.3 g < pga < 0,2 g Zone 2; 0.2 g < pga < 0.1 g Zone 3; and pga < 0.1 g Zone 4. The final product also provides the user the pga in terms of digital values for given coordinates. (C) 2002 Elsevier Science B.V. All rights reserved.