Seismotectonically Active Zones in the Dinarides

Abstract

Seismotectonically active zones are formed due to displacements of segments of the Adriatic micro-plate that differ in size and in their rate of movement, and by the resistance of the rock masses of the Dinarides. The spatial position of these zones can be determined through the locations of earthquake foci. The zones of seismotectonic activity are then correlated with the most important faults on the surface. The seismotectonically active zones are relatively steeply inclined in the shallowest 10-20 km, which is caused by the oblique contacts between the Adriatic micro-plate and the Dinarides. The zones are curved at depth in many cases, which reflects the compression of the area. Curved parts of the zones are characterised by the greatest pressures and also by the most frequent earthquakes. Mildly inclined zones reflect the reverse displacements in the area, also probably the activity on contacts between rock masses of different density, or the extension of the Adriatic micro-plate subduction. The southern part of the plate is the most active. The greatest pressures caused by these movements occur in the area between Mljet island and Dubrovnik. Therefore the majority of earthquakes, and notably the strongest ones, occur in the area between Split, Imotski, Hvar island and Dubrovnik, as well as along the Montenegro coast in a SE direction.