DETERMINATION OF THE LITHOSPHERIC STRUCTURE FROM CARPATHIANS ARC BEND USING LOCAL DATA

The main goal of this study is to investigate the lithospheric structure beneath Vrancea seismic area using local earthquakes. Vrancea area, located at the South-Eastern Carpathians Arc bend, is characterized by strong earthquakes generated at intermediate depths (60-170 km) in a complex geotectonic system. The tomography image resulted from teleseismic data (Martin et al. 2005; 2006) reveals a high-velocity body extended significantly beyond the seismic active zone in depth (going down to 400 km depth or even more), as well as laterally. An updated and revised catalog of 927 well-located events occurred between 1982 and 2006 in Vrancea and around was considered in the present study. The application of the tomography inversion for local events (Koulakov et al., 2007) allowed a notable increase of the resolution of the previous tomography image. The high-velocity body is strongly reduced in extension and practically mimics the distribution of hypocenters.