9218370 Shor In this project the PIs will examine the problem of how subduction initiates at the Macquarie Ridge complex, which occurs 1500km south of New Zealand and separates Pacific and Australian plates (Triple Junction with the Antarctic plate isn't too far either). The P.I.s argue that this is the best place in the world where to study this process. The field program includes side-scan sonar/bathymetric swath (Hawaii MR1), 6-channel seismic reflection, and gravity measurements aboard Moana Wave. The P.I.s will determine the deformation process and test two different models of subduction initiation.