<P> Continental drift is the movement of the Earth 's continents relative to each other , thus appearing to `` drift '' across the ocean bed . The speculation that continents might have ' drifted ' was first put forward by Abraham Ortelius in 1596 . The concept was independently and more fully developed by Alfred Wegener in 1912 , but his theory was rejected by some for lack of a mechanism ( though this was supplied later by Arthur Holmes ) . The idea of continental drift has been subsumed by the theory of plate tectonics , which explains how the continents move . </P>
what process causes the continents to drift apart how
Continental drift