According to continental drift, the continents change position very slowly, moving over the Earth's surface at the rate of only a few centimeters per year, adding up to thousands of kilometers over geological time. Until the mid-20th century most scientists believed that the continents were in a fixed position, Early supporters of continental drift, like Wegener, claimed that the jigsaw shapes of the continents could be pieced together to form an ancient landmass which, at some time in the past, split and drifted apart. Evidence for the theory included matching the outlines of continents, rock types, geological structures, and fossils. Fossil magnetism in rocks is used to calculate the ancient latitude of continents over time. Continental drift became accepted with the development of plate tectonics in the 1960s. In recent years continental movement has been confirmed by direct measurements made by global positioning satellites using laser beams.
Related category• GEOLOGY AND PLANETARY SCIENCE
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