Analysis and geophysical interpretations of data obtained from satellite and ground survey

Within the scope of this study, mathematical approaches have been applied by using satellite gravity model data in the western Anatolian, Aegean and Eastern Mediterranean regions and then from eastern Europe to the east of Caspian Sea. The first objective of the study is to obtain information about the crust structure of the study area by using satellite gravity data and the second is to obtain information about the horizontal and vertical continuity and physical properties of large-scale structural elements. In this study, firstly, spherical free-air gravity anomalies obtained from satellite gravity models and terrestrial free-air gravity anomalies were compared. In this way, GOCE model, which provides the best fit between anomalies obtained from ground data and satellite models, was determined as DIR-R4 model. Then the GOCE model and the EGM2008 model derived from the GRACE satellite were combined at certain levels and the anomalies required for the study area were calculated. In the second stage of this study, gravity disturbance data was used to determine the structural discontinuities of Western Anatolia and Aegean Region. This region includes many faults in the D-B direction within the Western Anatolia Expansion Area and important tectonic elements such as the Hellenic Subduction Zone. Within the scope of the study, in the area where recent big earthquakes occurred, crosssections have been taken and the gravity disturbance data has been tested to estimate depths of discontinuities. In addition, border analysis operators such as tilt angle, theta map, analytical signal and total horizontal derivative were used to compare the results. Within the scope of the thesis, the mentioned methods have been applied in a wide area including Europe with the support of Dokuz Eylul University's Scientific Research Projects (BAP No 2018.KB.FEN.013). First, spherical free-air gravity anomaly of the area was calculated by using satellite models. Then, gravity tensors, Moho (Mohorovicic) and LAB (Lithosphere-Asthenosphere Boundary) depth maps were obtained. Moho depth values were found to be consistent with the results of previous studies. Moho depth values were obtained between 10 and 50 km and LAB depth values were obtained between 80 and 180 km. In addition, firstly magnetic data obtained from MTA and free-air gravity anomalies were examined along with profiles. Along with the same profiles, gravity and magnetic anomalies were associated with the tectonic and geological units of the region. Positive magnetic anomaly and negative gravity anomaly areas are thought to be associated with thick crust or high magnetization, while negative magnetic and positive gravity anomaly areas may be related to thin-crust or high-density units and high heat flux.