Analyzing Crustal Velocity Structure of the Central Zagros (Ghir-Karzin region) Using Local Earthquake Tomography

The purpose of this study is to analyze the crustal velocity structure of the Ghir-Karzin region, which is located in Central Zagros. It has always been a challenging illustration of the deep subsurface structures for this region due to the thick (roughly ~۱۰ km) sedimentary cover. Generally, Local Earthquake Tomography (LET), by presenting different anomalies, has the potential of imaging velocity structures in ۳ dimensions that can provide valuable information about different subsurface structures. In this paper, we used a unique dataset of ۳۰۹ local earthquakes recorded by a dense local temporary network consisting of ۳۰ seismic stations alongside by using SimulPS۱۴ (a well-known and powerful code for retrieving seismic ۳D velocity) to calculate crustal structure of the study area. Many parameters, especially a wide variety of grid configurations were checked to obtain the most accurate velocity model. Near the surface of our tomography image, we found a good correlation between the elongation of velocity masses and the topographic trend in the area, which may suggest that the velocity is more affected by surface geology. In deeper parts, this relationship is likely to be substituted by underlying layers (upper crystalline crust), which may be more affected by blind faults.

کلیدواژه ها:

Central Zagros ، LET ، Configuration ، Surface geology ، Blind faults