Analyzing Crustal Velocity Structure of the Central Zagros (Ghir-Karzin region) Using Local Earthquake Tomography
عنوان دوره: بیستمین کنفرانس ژئوفیزیک ایران
کد مقاله : 1966-NIGS
نویسندگان
1پژوهشگاه بین المللی زلزله شناسی و مهندسی زلزله
2استاد و معاون پژوهشی پژوهشگاه بین المللی زلزله شناسی و مهندسی زلزله
چکیده
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 ~10 km) sedimentary cover. Generally, Local Earthquake Tomography (LET), by presenting different anomalies, has the potential of imaging velocity structures in 3 dimensions that can provide valuable information about different subsurface structures. In this paper, we used a unique dataset of 309 local earthquakes recorded by a dense local temporary network consisting of 30 seismic stations alongside by using SimulPS14 (a well-known and powerful code for retrieving seismic 3D 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
Title
Analyzing Crustal Velocity Structure of the Central Zagros (Ghir-Karzin region) Using Local Earthquake Tomography
Authors
Amin Aghaee Naeini, Saeed SoltaniMoghadam, Mohammad Tatar
Abstract
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 ~10 km) sedimentary cover. Generally, Local Earthquake Tomography (LET), by presenting different anomalies, has the potential of imaging velocity structures in 3 dimensions that can provide valuable information about different subsurface structures. In this paper, we used a unique dataset of 309 local earthquakes recorded by a dense local temporary network consisting of 30 seismic stations alongside by using SimulPS14 (a well-known and powerful code for retrieving seismic 3D 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.
Keywords
Central Zagros, LET, Configuration, Surface geology, Blind faults