M. KOUTEVA 1,2, GIULIANO F. PANZA 2,3, I. PASKALEVA 1, FABIO ROMANELLI 2
1 CLSMEE-BAS, Acad. G. Bonchev 3, 1113
Sofia, Bulgaria
2 DST-University of Trieste, E. Weiss
4, 34127 Trieste, Italy
3 The Abdus Salam ICTP, SAND Group, Strada
Costiera 11, 34100 Trieste, Italy
An analytical deterministic technique, based on the simultaneous account of
the fault mechanism and seismic wave propagation, has been applied to generate
synthetic seismic signals at Russe, NE Bulgaria due to the strongest intermediate-depth
Vrancea earthquakes, which occurred during the last century (1940, 1977,
1986 and 1990). Synthetic signals have been generated varying the seismic
source location, the parameters describing the movement in the source, and
the Vp/Vs ratio of the uppermost layer along the investigated profile. The
obtained results show that all ground motion components give a significant
contribution to the seismic loading and all the tensorial properties of the
earthquake sources influence the shape and the amplitude of the seismic signal.
The applied ground motion modelling approach has proved that the seismic
input (also at remote distances) can be constructed via waveform modelling,
considering all possible factors influencing the ground motion and enough
earthquake scenarios.
Key words: intermediate-depth earthquakes, ground motion modelling, site response, modal summation, modes coupling.