Soil and bedrock models were created to understand how earthquakes affect the ground. By using S-wave velocity, different types of bedrock were identified: soil, engineering bedrock, and seismic bedrock. The researchers used surface wave and microgravity methods to create 2D models in Izmir bay. They found that the soil is 300-400 meters thick with multiple layers, and its thickness changes from north to south. The engineering bedrock is made of Bornova melange, while the seismic bedrock is made of Menderes massif. Neogene limestone and andesite units at 200-400 meters depth indicate the engineering bedrock.