Deformation and displacements of Earth’s surface in Turkish earthquakes era in February 2023 by geodesy data

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The work analyzes the connection between a series of Turkish earthquakes in February 2023 and coseismic displacements and deformations on the Earth's surface. In areas of seismic rupture during the five days, there are recordings of three earthquakes on February 6 with magnitudes 7.8, 6.7, 7.5 and then for 5 days period – 42 events of magnitude 4.5–6.0. This work analyzed data obtained by various geodesy methods in the epicentral region. Coseismic effects in a 300 kilometers zone, covering a significant part of the East Anatolian Fault, are considered. Relative displacements up to 6 m have been recorded, with an average value 4 m. When for studying far-field effects, we used GPS network data from 27 international stations, of which seven stations located in Turkey. For the closest to the epicenters of the main aftershock on February 6, 2023, MERS station received coseismic 3D displacements up to 20 mm. The displacement and deformation fields have been constructed according to IGS data. Rates of coseismic deformations in the far zone reach up 10–8 , which is an order of magnitude higher than the background values of 10–9 . Post-seismic horizontal and vertical displacements rates of the Earth's surface in areas of Turkey, located to the southwest of the earthquake epicenters can be associated with floods. A study of displacements rates and deformations of the territory was carried out Turkey and its surroundings in the era of 2017–2023. Highlighted decrease displacement rates two years before seismic activation in 2023. The resulting picture of displacement and deformation rates reflects a current processes in the territory located on the borders of Anatolian Block and tectonic plates: Eurasian, Arabian, and African.