3-D crustal structure of the Simav - Küyahya and surrounding regions

Abstract

Kütahya and surroundings are quite complex structures from a tectonic and geological perspective. On May 19, 2011, an earthquake of magnitude M = 5.9 occurred in Simav. The purpose of this thesis is determination of the 3-D seismic velocity structure applying the local earthquake tomography method, using earthquakes that occurred between the years 2010 and 2015 in Kütahya Simav and surroundings. The signifigance of this study is that the first 1-D and 3-D tomographic inversion for Simav, Kütahya and surroundings is done by this study. The region's 1-D velocity model, 3-D velocity model and crustal structure are obtained. In this study, the 3-D velocity distribution up to 30 km depth of upper crust of the study area is determined with tomographic inversion methods. For this purpose, by creating data sets, travel time of phases were prepared by tomographic inversion format, appropriate model structure has been created, Vp, Vs and Vp/Vs models that obtained with appropriate resolution parameters and tomographic inversion, has been interpreted with geological and tectonic features of the area. At 30 km depth, P and S waves velocity structure of Kütahya, Simav and surroundings were obtained. The Graben system of the region is supported by the velocity cross-section obtained. The depth of the graben is determined as 20 km. The relationship between the hypocentre of the recorded earthquakes in the region and Vp, Vs, and Vp/Vs anomalies has been revealed with horizontal and vertical cross-sections. Comments are made about the structural differences of the region’s P wave and S wave velocity information and the physical properties of the rock’s Vp/Vs ratio information. Fault systems, potential fault zones and earthquake activity of the region are discussed with the combined results of the study.