Critical evaluation of strong motion in Kocaeli and Duzce (Turkey) earthquakes

Turkey was struck by two major events on August 17th and November 12th, 1999. Named Kocaeli (M-w = 7.4) and Duzce (M-w = 7.2) earthquakes, respectively, the two earthquakes provided the most extensive strong ground motion data set ever recorded in Turkey. The strong motion stations operated by the General Directorate of Disaster Affairs, the Kandilli Observatory and Earthquake Research Institute of Bogazici University and Istanbul Technical University have produced at least 27 strong motion records for the Kocaeli earthquake within 200 km of the fault. Kocaeli earthquake has generated six motions within 20 km of the fault adding significantly to the near-field database of ground motions for M-w >= 7.0 strike-slip earthquakes. The paper discusses available strong motion data, studies their attenuation characteristics, analyses time domain, as well as spectral properties such as spectral accelerations with special emphasis on fault normal and fault parallel components and the elastic attenuation parameter, kappa. A simulation of the Kocaeli earthquake using code FINSIM is also presented. (C) 2002 Published by Elsevier Science Ltd.