The San Andreas Fault (shown) is the boundary between the Pacific and North American plates. Plate tectonics revealed how Earth’s surface features are intrinsically linked to its hot interior. Tuzo Wilson compared the impact of this intellectual revolution in earth science to Einstein’s general theory of relativity, which had produced a similar upending of thought about the nature of the universe. When plate tectonics emerged in the 1960s it became a unifying theory, “the first global theory ever to be generally accepted in the entire history of earth science,” writes Harvard University science historian Naomi Oreskes, in the introduction to Plate Tectonics: An Insider’s History of the Modern Theory of the Earth.
The planet’s familiar landscapes, we now know, are products of an eons-long cycle in which the planet constantly remakes itself. Plate tectonics reveals how Earth’s surface is constantly in motion, and how its features - volcanoes, earthquakes, ocean basins and mountains - are intrinsically linked to its hot interior. But the theory of plate tectonics has rocked this picture of the planet to its core. For centuries, the outermost layer of Earth was thought to be static, rigid, locked in place.
