A Study on Investigation of Crustal Deformation and Block Kinematics Along the Eastern Sector of the NAF by GPS Measurements

This study constitutes part of an integrated project that have been carried out jointly by the Kandilli Observatory and Earthquake Research Institute (KOERI) and the TUBITAK-MAM to investigate crustal deformation and block kinematics by Global Positioning System (GPS) measurements in and around the eastern sector of the North Anatolian Fault (NAF) Zone. The integrated project is also include investigation of seismicity and earthquake potential. Additionally the Radon gas emissions will also be monitored on-line, near real-time along active fault zones in an attempt to predict earthquakes. The region is an ideal choice to carry out the above mentioned investigations, because due to the northward movement of the Arabian Plate, the Erzincan-Karliova region is squeezed, crushed, and expelled westward along the NAF and East Anatolian Fault Zones. The active fault pattern indicates that maximum crustal shortening and crustal deformation in Turkey takes place in this region. Despite this, the Yedisu segment of the NAF was identifed as a seismic gap and it has not been broken entirely since the 1784 earthquake. This region is the most tectonically active region in Turkey as far as the major earthquake occurences are concerned and it is capable of generating major earthquakes in every 3-4 years. It is quite obvious that following the 1992 Erzincan and 2003 Pulumur Earthquakes the Coulomb stress loading on the Yedisu segment of the NAF have been increased significantly and the region needs to be monitored vigilantly with the full armament of geophysical techniques such as seismic (network), geodetic (GPS, InSAR), and geochemical (Radon emissions) techniques. First period GPS measurements were performed at twelve GPS stations in the area. This study reports the evaluation of this GPS data.