Final answer:
Geophysics is used to map out the ocean floor by conducting seismic surveys, which provide data about the subsurface features and composition. By analyzing the patterns of reflectivity, geologists can create three-dimensional maps of the ocean floor.
Step-by-step explanation:
Geophysics is used to map out the ocean floor because it allows geologists to study the subsurface features and composition of the ocean floor. Seismic surveys, which involve sending sound waves into the seafloor and recording how the waves reflect back, provide valuable data about the rock types, deformation features, and the presence of water or petroleum below the surface. By analyzing the patterns of reflectivity, geologists can create three-dimensional maps of the ocean floor.