9730786 Babcock This is a study of existing multichannel siesmic data to determine crustal thickness variations and the character of Moho reflectors. The objectives are to obtain precise crustal thickness measurements at the segment scale, to ascertain the continunity and character of Moho reflections and their relationship to the ridge crest, to examine the response of Moho reflections to identify other geologically plausible crust-mantle transitions.