Naked Earth: 8the New Geophysics

Geophysics is undergoing a ``whole-earth revolution,'' with changes at Earth's molten core increasingly linked to what is going on at its surface. Vogel, a former editor for Discover, brings a weighty subject vibrantly to life in this exciting report. It is common knowledge that the continents once formed a giant landmass, called Pangaea, 180 million years ago, yet many readers will be unfamiliar with the Supercontinent Cycle--the belief, now shared by many geophysicists, that the Pangaean supercontinent was a recurrent, not a one-time, phenomenon. Furthermore, the existence of Pangaea seems to be stored like a memory in inner Earth's rocks and may be dictating where enormous floods of magma (molten rock) erupt. These eruptions in turn have been linked to the reversal of Earth's magnetic poles, a flip-flop that supposedly has occurred 300 times in the last 200 million years. Vogel evokes a dynamic underworld of powerful currents of liquid rock; colliding tectonic plates; fossil volcanoes that have spewed out natural diamonds; and 30-foot-tall mineral chimneys soaring above the Pacific Ocean floor, natural warm-water vents for dispersing heat from Earth's core. This is top-notch science journalism. (May)