Seismic Ground Motion and Site Effect Modelling Along Two Profiles in the City of Debrecen, Hungary

The aim of our study is to determine the disign ground acceleration values at different parts of Debrecen along two profiles crossing the city. This technique consists of the modal summation method, followed by finite difference modelling. Two independent computations have been performed using two different seismic sources and profiles. In both computations the seismic sources have been located in the so called "Mobile Zone". The Mobile Zone is a seismically active fault system between the villages of Hosszupalyi and Galospetri. the focal mechanism and the homogeneous and heterogeneous parts of the profile are known from gephysical and geological data of the investigated area. The maximum responge spectra ratio values of the horizontal component are found below 1 Hz all along the profile and the frequencies below 1 Hz are in good agreement with the natural frequencies of the multi-storeyed buildings. Computed effective than 6 MSK macroseismic intensity values estimated from the assessment records of damages wrought by the 1834 Ermellek earthquake.