Seismic Hazard investigation by Strain Rate Variation Study in the Zagros-Makran Transition Zone by Using GPS Velocity Vector Data

The transition zone between the Zagros and Makran has a special place in tectonic studies in the region. The mechanism of the transition from the continental collision in the Zagros to the oceanic-continental subduction in Makran has raised some questions from the tectonics and geodynamics point of view, and these questions, in turn, has caused GPS campaigns and studies in this region and adjacent areas. In this study, the interpolation of GPS velocity vectors on a rectangular grid and strain calculation in the center of each cell was used to study the strain rate variations in this range. Noticeable spatial changes in the principal axes of the geodetic strain rate were observed in different parts of the Zagros and Makran transition zones. The anomalies observed in the calculated quantities showed significant correlations with seismicity and mechanisms of faulting on important faults in the region. In this study, a new method for mapping directional quantities utilizing a color scale with a circular pattern is also proposed for the first time. The direction of the strain rate axes in the study area was mapped by this new method and the anomalies observed were compared with the areal and maximum shear strain rate maps and interpreted based on seismological facts and observations.