The seismic microzonation map of Yenisehir-Bursa,
NW of Turkey by means of
ambient noise measurements
Unal DİKMEN and Mete MİRZAOĞLU
General
Directorate of Disaster Affairs, Earthquake Research Department, Ankara, Turkey
Abstract: This paper describes the results of
the study of seismic microzonation at Yenisehir-Bursa which is located at the Northwestern part of
Turkey. Seismic noise measurements have
been made at 151 sites. Short periods (less than 1 second) were taken into
account at the main peak in the spectral ratio between the horizontal and the
vertical components. At the investigated area, two maps were prepared that show
the spatial variations of the predominant period and seismic amplification
according to Nakamura’s technique. The analysis shows that
the north and south edges of the Yenisehir basin have
relatively high predominant periods and high seismic amplification compared to
the centre of the basin. This result is in line with the theory of topographic
effects on seismic amplification and also confirmed the suitability of the H/V
spectral ratio of ambient noise as a geophysical exploration tool in seismic
hazard assessment.