An Introduction to Energy Flow and the Discovery of the Great Plates

This chapter begins with a discussion about the flow of energy. The story begins with a short history of the discovery of mantle convection. In the early part of the twentieth century, the ideas that continents slowly move around on the surface of the Earth was put forth, but after a couple of decades the idea remained stagnant. Then it was found that these continents were on great rigid moving plates that are formed at ocean ridges. The plate material in the seafloor moves away from the ridges and ultimately plunges back into the Earth at ocean trenches. This chapter tells of how the primary features of the great plates were discovered and how sinking slabs of cold ocean floor within the mantle of the Earth were detected. These were shown to drive the plates in the 1960s and early 1970s.