Akademik Veri Yönetim Sistemi
Yerbilimleri/ Earth Sciences, cilt.37, sa.2, ss.81-92, 2016 (Scopus)
In this study, to investigate the characteristics of the subterranean structures under dynamic conditions the geophysical data were collected in approximately 4 km along EW direction and 5 km along NS direction in an area of 20 km2 in the North of İzmir Bay. At the scope of the study Multi-Channel Analyses of Surface Waves (MASW) method which uses the dispersive feature of Rayleigh type surface waves is used. Shear wave velocity (VS30) up to 30 meters deep is obtained with MASW method, using these velocity values predominant site period (PSP) and density changes are calculated. Furthermore PSP changes are calculated using the recorded microtremor method data at 112 points in the study area. To examine the site structure of the study area and common interpretation seismic velocity and the other distribution maps derived from the seismic velocities with Bouguer gravity maps which were created using microgravity method data. To common interpret the distribution maps obtained from Microtremor and MASW methods with Bouguer gravity distribution map which were created using microgravity method. It is observed at distribution maps that the points where PSP values obtained from Microtremor single point measurements are greater than 1 second overlaps the locations where VS30 velocities are lower than 700 m/sec. At the locations that overlapping can said the alluvium soil takes place and engineering bedrock depth is more than 30 meters. It can be said that the study area can be divided into two separate parts by a NW-SE trending boundary line in terms of physical properties according to the parameters obtained from the methods applied at the study area by looking at the distribution maps. Higher velocity values and also higher density and lower PSP values obtained by these velocities were observed at the north of this line. These findings led us that the northern part of the area consists of geological units which are more resistant to earthquakes but towards the bay coast at southern part of the area there exists weaker geological units. The findings obtained according to the scope of the study are compatible with the geology and tectonic features of the region.