Bedrock structure in Adapazari, Turkey - a possible cause of severe damage by the 1999 Kociaeli earthquake


Komazawa M., MORIKAWA H., NAKAMURA K., AKAMATSU J., NISHIMURA K., SAWADA S., ...More

SOIL DYNAMICS AND EARTHQUAKE ENGINEERING, vol.22, pp.829-836, 2002 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 22
  • Publication Date: 2002
  • Doi Number: 10.1016/s0267-7261(02)00105-7
  • Title of Journal : SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
  • Page Numbers: pp.829-836

Abstract

The 1999 Kocaeli earthquake brought serious damage to downtown of Adapazari. To study why strong motions were generated at the town, a bedrock structure was investigated on the basis of Bouguer gravity anomaly, and SPAC and H/V analyses of microseisms. It was revealed that, the basin consists of three narrow depressions of bedrock with very steep edges, extending in E-W or NE-SW directions along the North Anatolia faults, and the depth to bedrock reaches 1000 in or more. Downtown of Adapazari is located 1-2 km apart from the basin-edge. It is considered that, the specific configuration of bedrock amplifies ground motions at the downtown area by focusing of seismic waves and/or interference between incident S-waves and surface-waves secondarily generated at the basin-edge. Studying 3D bedrock structure is an urgent issue for microzoning an urban area in a sedimentary basin. (C) 2002 Elsevier Science Ltd. All rights reserved.