Ocean Basin

Further evidence of seismic activity in the ocean basins is the presence of fracture zones. These are regions where, along numerous faults, sections of the ocean floor slide past each other, relieving tension created by seafloor spreading at the ocean ridges. Ocean crust in a fracture zone looks like it has been sliced up by a giant knife. The faults usually cut across ocean ridges, often nearly at right angles to the ridge. A map of the North Atlantic Ocean basin, for example, shows the Mid-Atlantic Ridge traveling from north to south across the middle of the basin, with dozens of fracture zones cutting across the ridge from east to west.

Some of the largest fracture zones are located along the eastern edge of the Pacific Ocean. The Clipperton And Clarion Fracture Zones, for example, originate along the western coast of Mexico and extend up to 3,300 mi (5,300 km) to the west. At their maximum, these zones may be almost 30 mi (50 km) wide and 10,500 ft (3,150 m) deep.