Seismic hazard in the Istanbul Metropolitan Area: A preliminary re-evaluation

Kalkan E., Gulkan P., Ozturk N. Y., Celebi M.

JOURNAL OF EARTHQUAKE ENGINEERING, vol.12, pp.151-164, 2008 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 12
  • Publication Date: 2008
  • Doi Number: 10.1080/13632460802013925
  • Journal Name: JOURNAL OF EARTHQUAKE ENGINEERING
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.151-164
  • Keywords: sea of Marmara region, probabilistic seismic hazard, ground-motion prediction, NORTH ANATOLIAN FAULT, MARMARA SEA, ACTIVE FAULTS, TURKEY, SLIP, MAGNITUDE, REGION, MOTION
  • Middle East Technical University Affiliated: Yes

Abstract

In 1999, two destructive earthquakes (M7.4 Kocaeli and M7.2 Duzce) occurred in the north west of Turkey and resulted in major stress-drops on the western segment of the North Anatolian Fault system where it continues under the Marmara Sea. These undersea fault segments were recently explored using bathymetric and reflection surveys. These recent findings helped to reshape the seismotectonic environment of the Marmara basin, which is a perplexing tectonic domain. Based on collected new information, seismic hazard of the Marmara region, particularly Istanbul Metropolitan Area and its vicinity, were re-examined using a probabilistic approach. Two seismic source and alternate recurrence models combined with various indigenous and "foreign'' attenuation relationships were adapted within a logic tree formulation to quantify and project the regional exposure on a set of hazard maps. The hazard maps show the peak horizontal ground acceleration and spectral acceleration at 1.0 s. These acceleration levels were computed for 2 and 10 % probabilities of transcendence in 50 years.