Abstract:
The territory of Bulgaria represents a typical example of high seismic risk area. In the present study deterministic scenarios in intensity for two Bulgarian cities (Ruse and Plovdiv) are presented. By deterministic scenario it is mean a representation of the severity of ground shaking over an urban area, using one or more hazard descriptors. Such representation can be obtained: – either from the assumption of a “reference earthquake” specified by a magnitude or an epicentral intensity, associated to a particular earthquake source – or, directly, showing values of local macroseimic intensity generated by a damaging, real earthquakes of the past. In the study we chose for the second method using the values of macroseimic intensity caused by damaging historical earthquakes (the 1928 quakes in southern Bulgaria; and the 1940 and the 1977 Vrancea intermediate earthquakes).