Vp/Vs from Two Different Mode Converted Arrivals

A33 VP/VS FROM TWO DIFFERENT MODE CONVERTED ARRIVALS Abstract 1 Both the locally converted C-wave and the Purnell mode (S-wave) can be used to determine the Vp/Vs ratio beneath salt. These Vp/Vs ratios can be transformed into pore pressures to guide drilling activities. We forward modeled a generalized flat layered earth with a thick salt body in a deepwater setting. The reduced C-wave and Purnell mode traveltimes can be easily converted into Vp/Vs ratios when combined with the P-wave traveltime. The Vp/Vs so deduced from traveltime measurements is exactly correct only for an exactly vertical ray but acceptable (less than