What was discovered in the Atlantic Ocean that helps confirm the Theory of Continental Drift?

The Mid-Atlantic Ridge, which is a spreading rift in the floor of the central Atlantic Ocean that extends the entire north-south length of the Atlantic. Along this rift, the sea floor is spreading apart to the west and east, creating new crust which carries the continents adjacent to the Atlantic apart at about the same rate as human fingernails grow. This crustal up-welling and spreading is generated by enormous currents in the Earth's mantle, which is the deep semi-molten layer in the Earth directly below the Earth's crust. Volcanic activity appears in many locations of this rift, including the volcanic island of Iceland, which is split by this rift. The spreading of the Mid-Atlantic Ridge was confirmed by measured successive magnetic signature reversals in the newly-created crust along the rift which matched exactly many cycles of reversal in the Earth's global magnetic field over millions of years when the Earth's north and south magnetic poles reversed. GPS technology can document this slowly-increasing separation of continents adjacent to the Atlantic created by the Mid-Atlantic Ridge.