Analysis of local site conditions through geophysical parameters at a city under earthquake threat: Canakkale, NW Turkey


BEKLER T. , DEMİRCİ A. , EKİNCİ Y. L. , BÜYÜKSARAÇ A.

JOURNAL OF APPLIED GEOPHYSICS, cilt.163, ss.31-39, 2019 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 163
  • Basım Tarihi: 2019
  • Doi Numarası: 10.1016/j.jappgeo.2019.02.009
  • Dergi Adı: JOURNAL OF APPLIED GEOPHYSICS
  • Sayfa Sayıları: ss.31-39

Özet

Canakkale is the second province, after Istanbul, that has territories in both Asia and Europe. The city, also known as Dardanelles, is located on the Gallipoli peninsula in the northwest of Turkey, and the Biga peninsula which is an extension of Anatolia at the west. The region is tectonically quite active and it has high earthquake generation potential. The city has experienced a significant earthquake (Mw = 6.8) once again that occurred on May 24, 2014. In addition to these challenges, remarkable part of the city's territory and also potential new settlement areas are located on thick alluvium. Thus, mentioned-above disadvantages clearly increase the importance of this study, which focuses on determining the areas having different earthquake hazard potentials with regard to local site conditions by performing seismic risk assessments, as well as providing a basis for the preparation of settlement suitability maps on different scales that will lead knowledge for zoning plans. To that end, an integrated geophysical and geotechnical study was performed in a detailed manner. Multi-channel analysis of surface waves (MASW) and microtremor (MT) measurements were carried out at properly distributed 110 stations representing the whole survey area. The geotechnical study, planned to contribute geophysical interpretation, involved the drilling of 110 boreholes that are close to geophysical measurement stations. In addition to examining Vs30 variations based on the MASW, the ground dominant vibration period maps were also produced through MT time series analysis. In particular, the mean Vs velocity (Vs30) up to the first 30 m and the ground oscillation period change based on spectral amplitude ratios (HVSR) yielded substantial information that helped generate the seismic microzonation maps and also make the ground classification. These outputs contributed to exhibit the risk zones in the coastal city that has a dense and narrow settlement plan. (C) 2019 Elsevier B.V. All rights reserved.