Characteristics of the velocity gradient in the upper mantle of the Carpathian-Balkan region

Used three-dimensional P-velocity model of the mantle, built by the method of Teylor approximate solution seismic tomography proposed by V.S.Geyko. This method gives a more accurate approximation of non-linearity and can be used at a lower velocity limits for functions, do not require setting the reference model as the initial approximation, gives the correct by Tikhonov.

The analysis of changes in the velocity gradient with depth Carpathian-Balkan region allowed in the mantle under different tectonic structures highlight layers in which the velocity gradient increases, decreases or is constant with depth. Shown top and bottom of selected layers. Shows how to behave velocity gradient with depth in the vicinity of the Vrancea zone, which is characterized by the presence of intermediate depth earthquakes in the 70–200km.