9504118 Mann The Pis will carry out a sidescan bathymetry and geophysical survey of the Puerto Rico Trench (PRT) and northern slope to map the zone of active collision at the N. American/Carribean Plate boundary. Key questions to be addressed include: Does the main ridge form a boundary between more deformed and less deformed seafloor? Is it a subducting feature and how much of it is subducted? What's the relationship of thrust and strike-slip faults? The study will provide a better understanding of the seismogenic potential of this submarine deformation zone that lies within 150 km of the island of Puerto Rico. ***