The tomography of the velocity propagation distributions of the P_n seismic waves both in an isotropic and anisotropic conditions, compared with the lateral variations of that velocity has highlighted the physical properties of the uppermost mantle and crustal thickness of the Earth. A study analyzed 700 earthquakes occurred in Turkey from 1999 to 2010 with magnitude degree major than 4.0 and the related 50.000 Pn first arrivals recorded by 832 seismic stations at a distance range of 180-1500 kms from the epicenter. The tomography highlighted that "Pn velocities are found to be lowest in eastern Turkey (<7.6 km s-1) and highest in the eastern Mediterranean Sea and Zagros Suture (>8.3 km s-1). Large Pn anisotropy is observed in the Aegean, central Anatolia and along the southern coast of Anatolia. [...] Large crustal thicknesses are observed along the Dinarides-Hellenides and along the southern coast of Anatolia."