Contemporary velocity field for Turkey inferred from combination of a dense network of long term GNSS observations

Abstract

The Anatolia-Aegean domain represents a broad plate boundary zone, with the deformation accommodated by major faults bounding quasi-low deforming units. First-order features of this deformation were obtained in the form of a GNSS-derived velocity field. During the last decade, the accuracy of velocity solutions was improved, and the expansion of continuous networks increased spatial resolution. Nonetheless, an accurate representation of the deformation field requires interstation distances much lower than the locking depth of nearby faults, which has not yet been satisfied. The basis for creating a precise and accurate velocity field is uniform processing of the time series recorded both in the campaign and permanent GNSS stations, at once and for a single reference system. Although for Anatolia the data density has increased 6-fold since the landmark work of Reilinger et al. (2006), this crucial integration has not been made. We aim to fill this gap by analyzing the data and providing a uniform velocity solution. In this study, we processed the time series of 836 stations, of which 178 are published for the first time. With a period of up to 28 years, we present the most accurate velocity field with increased spatial and temporal resolution and homogeneity. We used the improved coverage of the velocity field to calculate strain accumulation on the North and East Anatolian Faults. Modelled slip rates vary between 20 and 26 mm/yr and 9.7 and 11 mm/yr for the North and East Anatolian faults, respectively. The data can better constrain the kinematics of continental deformation, provide accurate boundary conditions for dynamic models, and help test outstanding hypotheses about the kinematics of the Anatolia-Aegean domain.