M.Sc Tezi Görüntüleme

Student:	Aygün ERDURAN
Supervisor:	Assis. Prof. Dr. Yusuf BAYRAK
Department:	Geophysical Engineering
Institution:	Graduate School of Natural and Applied Sciences
University:	Karadeniz Technical University, Turkey

Title of the Thesis:	Examination of the Source Parameters of the Earthquakes Occured in the Different Seismic Zones of Turkey and Determination of the Relations Between these Parameters and Active Fault
Level:	M.Sc
Acceptance Date:	1/5/2002
Number of Pages:	68
Registration Number:	i1270

Summary:

In this study, the earthquakes for the time period 1900-1992 come from the Hypocenter Data Base prepared by USGS and for the time period 1993-2001, the PDE data and IRIS data are used. Also, the data containing the focal mechanism solutions of the earthquakes are taken from Harvard CMT solutions. Turkey has been divided into eight different seismic regions taking tectonic environments and epicenters of the earthquakes in to consideration to examine variations of different source parameters for the regions. Concerning the relationships calculated between magnitude types for the different regions, a uniform catalog of Ms has been constructed. Seismicity parameters (a and b) of the Gutenberg-Richter relationship, the modal (a/b) values, expected maximum magnitudes (Mmax), the relationships between surface wave magnitude (Ms) and seismic moment (Mo) and average stress drop (Ac r) are calculated for each region. The results are discussed for the tectonic structures of the regions.

The highest a- values are observed in the west Anatolian region, but the lowest b- values are estimated for the North Anatolian fault (KAF). It is observed that the modal values (alb) represent regional seismicity very well. The highest a/b- values are observed in KAF, and the lowest values in the Mid Anatolian region. The results show that there is a linear relation between a/b- values and expected maximum magnitudes (Mmax). The highest Mm. values are found in KAF similar to a/b-values. Since three largest earthquakes in the twentieth century have been occurred in KAF, the highest moments and stress drops are estimated in this region. These observations suggest that there is a correlation between stress drops and b values.

Considering the parameters calculated for the different regions, it is resulted that the most hazardous regions in Turkey are KAF, the west Anatolia and East Anatolia regions, respectively.

Key words: Gutenberg-Richter Relationships, Magnitude, Modal Values, Seismic Moment, Stress Drop