Crust structure modeling with gravity data in Mid-Karadeniz region

The Mid-Karadeniz Region is a tectonically important region. The seismic activity of the zone is high throughout the fault zones and relatively low in other places. In this study, the causes of seismic activity differences were investigated using EGM08 Bouguer gravity anomalies and seismicity information for last 30 years of the region. The mean depths of the soft and hard sediment, basement, Conrad and Moho interfaces have been determined using the radial mean power spectra of the Bouguer gravity anomalies of the region. In addition, the cut-off wavenumber has been determined for filtering the Bouguer gravity data to calculate the depth of the Moho topography. The mean depths of the soft and hard sediment, basement, Conrad and Moho interfaces have been calculated as 2,812 km, 6,418 km, 10,980 km and 39,956 km, respectively by the linear segments of the spectrum in different trends. The Parker-Oldenburg algorithm has been used to model the geometry of the Moho topography. The gravimetric Moho that was calculated using EGM08 Bouguer gravity anomalies and the isostatic Moho that was calculated using topographic data were compared. As a result of this comparison, the correctness of the gravimetric Moho has been revealed. Then, Moho surfaces were calculated using different empirical formulas. The calculated surfaces were compared and thus the Moho topography of the region was modeled in the most accurate way.