The Atlantic Ocean was created by slow (3 centimeters a year) seafloor spreading along the Mid-Atlantic Ridge. This under-sea ridge is dominated by faults rather than volcanic features because relatively little magma is erupted as lava. The result is a great undersea rift valley, with cliff like fault scarps 2 kilometers high.
Topic: Earth Science
Keywords: Atlantic Ocean, Faults (Geology), Mid-ocean ridges, Rifts (Geology)