Interseismic Strain Accumulation Along The Tabriz-Van (Iran-Turkey) Shear Zone

In order to improve our understanding of the present-day  continental deformation in the Iranian-Turkish plateau we map the surface motions across the Iranian-Turkish boundary between Ardabil (NW Iran) and Van (E Turkey) using Sentinel-1 satellites’ TOPSAR data between 2014 and 2021 on descending (6, 79, 152) and ascending (101, 174 and 72) tracks. Interferograms generated with GMTSAR are used to calculate PS-InSAR time series with the multi-temporal InSAR analysis tools of the StaMPS software. Mean line of sight (LOS) velocity fields reveal a dominant right-lateral shear zone between Tabriz and Van acting as a boundary between Eurasian and Arabian plates. The Tabriz-Van shear zone (TVSZ) comprises the North Tabriz, Kotur, Ozalp and Ercis faults. We model the LOS velocity fields using TDEFNODE, a fortran package for block modelling and estimate slip rates and locking depthes along the TVSZ. The best fitting model suggests a 9±2 km of looking depth and a westward increasing slip rate from 7 to 10±2 mm/yr, consistent with GNSS observations. To the west the TVSZ appears to join with Karliova Triple Junction (KTJ). This dextral slip fault zone accommodates a part of motion resulting from the Arabia–Eurasia collision and has experienced a westward migration in M > 5 events since the 18th century including the 18th and 19th century M > 7 events along the North Tabriz Fault.