Determination of crustal movements with GPS observations around the Kahramanmaras triple junction system

The aim of this study is to provide information about horizontal crustal deformation and strain accumulations by using GPS technique in the southern part of Eastern Anatolian fault line. For this purpose, 4 periods GPS data between 2006 and 2009 at 15 stations placed on the region are acquired from 'TUBITAK-MAM Earth and Marine Science Enstitute'' within the scope of ''TUBITAK 1007 project titled multidisciplinary Earthquake Research in High Risk Regions of Turkey Representing Different Tectonic Regimes (Number 105G019)''. In addition, the GPS data between 2009 and 2014 of 14 GPS stations of TUSAGA-Active Network are included in deformation analysis. GPS data are procesed with Bernese 5.0 GPS Software, time-dependent horizontal displacements are determined. Classical deformation analysis is applied to derive whether thedisplacement are significant or not. The determined velocity values in the region show that the stations in the east of Eastern Anatolia fault line (on the Arabian plate) move from west to east approximately 7-10 ± 0.5-1.4 mm/yr while the stations in the west side of EAFZ (on the Anatolian plate) move counter clockwise approximately 11-13 ± 0.4-1.2 mm/yr in horizantal place. The strain analysis in horizontal place indicates significant strain accumulation in the area. The obtained values obtained from strain analysis is principal strain parameters, εmax = 0.142 μstrain, εmin = -0.145 μstrain, φ = 73.728 degree; share parameters, γ1 =-0.076 μstrain, γ2 = 0.033 μstrain; diferantial rotation parameter, ω =- 0.011 μrad. These results show the significant strain accumulation in the region.