In 1963, Fred Vine, Drummond Matthews, and others found that the crust surrounding the midocean ridges showed alternating bands -- each band magnetized with a polarity opposite the surrounding bands.

Photo: Harry Hess argues that the continents had once been one, and have drifted apart. With the discovery of plate tectonics and the mapping of the earth into about 12 plates, plus the understanding ...

In the new work, the researchers considered various possible initial conditions for the area and ages of ocean crust, as well as crust destruction rates, calculating that the ancient seafloor ...