7th BgGS National Conference With International Participation GEOPHYSICS 2015, Sofya, Bulgaria, 20 - 23 May 2015, no.19
All the large earthquakes that have occurred in Turkey are largely on the borders of the compressional/extensional strains. However, the nature and characteristics of strain patterns of seismic deformations in Turkey have not yet been reported. This study, for the first time, describes and maps the geographic distribution of the normal and shear strains using the Turkish Real Time Kinematics-Continuously Operating Reference Stations Network (RTK-CORS Network from 2009 to 2012). We analyze the strains with respect to the CORS network and estimate the horizontal/vertical components of strain tensors using GPS velocity data. We utilized the delaunay triangulation model and carried out biharmonic spline interpolation method to obtain the strain component maps. The normal and shear strain variations along the x, y, z-axes and the xy, xz, yz-planes, respectively, show that vertical displacements are quite effective on the tectonic processes. The normal strain in the vertical direction exhibits a structure in coherence with the topography and the extension stands out in the regions with high mountains. The main deformational component is the shear strain on the yz-plane that determines the faulting mechanisms in Turkey. The normal strain along the y-axis and horizontal shear strain on the xy-plane have a great importance in terms of the general movements of the Anatolian Block along the E-W direction. We conclude that the normal and shear strains appear to be a very subtle barometer for tectonic stress conditions within Turkey, and that strain analysis can be of great importance in understanding the nature and characteristics of seismicity of Turkey.