Observation of crust movements along the North Anatolian fault Bolu – Çorum segment by GNSS method

Studies on determining crust deformation have been carried out by scientists working in different fields from the past to the present. One of the consequences of crustal deformations is the earthquake. The consisting of the earth's crust from continuous moving plates has given a new dimension to earthquake studies. Due to the approach provided by the new viewpoints, geodetic surveying techniques have been able to provide infrastructure for earthquake studies since the early 1900s. One of the most important studies for earthquake prediction is the periodic monitoring of deformation networks established on fault lines. GNSS (Global Satellite Navigation Systems) used by geodesy is one of the most important tools used in these studies. GNSS, used in geodetic studies, has found a wide range of applications since the 1980s, leaving behind classical measurement techniques. Determination of crustal movements using GNSS technology provides high accuracy, time savings and it is much cheaper than many other applications. There are many active fault zones that cause earthquakes in the world. One of the most important of these is the North Anatolian Fault Zone (NAFZ), an important area of study for scientists. After the earthquakes of Gölcük and Düzce that took place in 1999, many studies have been carried out to determine the size, time and location of the earthquake, which is believed to be under the Marmara Sea, and which can bring the fault that is not broken by these earthquakes. Other segments of KAFZ, which are approximately 1100 km long, can tell us about the expected Marmara earthquake. Therefore, other segments of the fault has also of great importance. Periodical GNSS measurement campaigns were carried out in the years 2014, 2015 and 2016 in the GNSS network, which was established as 22 points in 2014 in order to determine the movements of the ground crust in the area between KAFZ and Bolu-Çorum. GNSS campaign measures were analyzed and velocity vectors of the region were created. GAMIT / GLOBK software was used for the evaluation of GNSS metrics. In order to get accurate results with GAMIT / GLOBK software, all stages of the studies are explained in details. When the values calculated by GAMIT / GLOBK software are examined, it is observed that the velocity (East-West component) along the fault is about 14 mm in the İsmetpaşa segment located in the study area and the velocity (East-West component) along the fault is about 10 mm in the Destek segment. In this study, the velocities of the points forming the GNSS network and the motion of the fault are explained in detail.