Earthquake activity on the Balkans
This is one of the most active regions in the AH belt. Most of the earthquakes take place at depths of up to 60-70 km. The relatively small depth greatly increases the degree of impact on the Earth’s surface. Intermediate-focus earthquakes (with a depth of 100-200 km) occur only in the area of the Vrancea and the Hellenic Arc. The Hellenic Arc is considered a complex subduction zone of the African plate below the Eurasian one. The great depth of earthquakes in the Vrancea region greatly increases the area of impact.

Earthquake activity on the territory of Bulgaria

The territory of Bulgaria belongs to the earthquake-prone areas of Earth. Earthquake activity in Bulgaria is related to the zones of complex interaction of geotectonic structures of different ranks.

  • Based on seismological and tectonic criteria, the territory of Bulgaria is divided into three main seismic regions: Northeastern, Srednogorski and Rila-Rhodope regions. These areas cover six main seismic zones: Gornooryahovska and Shablenska belong to the Northeastern region; Sofia and Marishka zones to Srednogorski and Kresna and Rhodope to the Rila-Rhodope region.

 

  • The available seismological information shows that strong (M> = 7) crustal earthquakes have been generated in the past centuries in all three regions.
  • The Rila-Rhodope region is characterized by the highest seismic activity, where in 1904 the strongest shallow earthquake (Mw = 7.6, Io = X-XI MSK) ever registered in the XX century in the Balkans and continental Europe took place near the town of Kresna.

 
Fig.1 Seismicity of the Balkans Fig.1 Seismicity of the Balkans Сеизмичност в България

Fig.2 Seismicity in Bulgaria