P108 CALCULATION OF TRAVELTIMES FOR REFLECTED CONVERTED WAVES USING THE COMMON CONVERTING ELEMENT METHOD D. GARZA-ROCHA U.A.N.L. Facultad de Ciencias de la Tierra A.P. 104 67700 Linares N.L. Mexico ABSTRACT In the present paper are carried out numerical calculations of a new approximation to obtain the traveltime for P-SV re ected converted waves. A set of sources emit P-waves and they travel to a given interface. These waves are converted in S-waves after the re ection and they are recorded at the corresponding receivers as P-SV converted waves. Common converting elements (CCE) have been simulated by fans of rays emmitted