Strong motion estimates taking into account site effects in the city of Thessaloniki (Greece) from source modeling of the Kozani and Arnea 1995 events

We model the slip on the fault related to two 1995 events in Greece: the Kozani (M6.6) and Arnea (M5.8) earthquakes.We use the strong motion waveforms recorded in northern Greece to retrieve by a forward modelling the source characteristics of the two events. Both point-source and finite-source models are used and different 1D structural models tested. Due to the absence of absolute timing of most of the recordings, the modelling is limited to fitting the peak ground acceleration (PGA) at the bedrock stations. The best results in terms of the PGA is obtained with the finite source models for a two-asperity k-squared distribution. The source model for the Kozani event is compatible with the main fault and antithetic fault model proposed by Hatzfeld et al. (1997). Given the two source models, we compute the related synthetic seismograms at a series of sites located in the city of Thessaloniki. We estimate the strong ground motion that would have been recorded by these two events at different sites in the city by convolving the synthetic bedrock signals with the 1D and 2D amplification curves obtained by Triantafyllidis et al (2003; 2004).