Deep in the Earth's crust, almost a mile beneath the ocean floor, a pool of superheated magma pushes against the surface layer of rock. At several thousand degrees Fahrenheit, the heat and pressure are awesome. The rock layer buckles, and a ridge on the ocean floor rises several meters before slamming downward and outward. The molten rock and superheated steam explode, and two huge rock plates, each thousands of miles wide, are pushed a few centimeters apart. A few centimeters doesn’t sound like much, but an entire continent has suddenly moved. The resulting earthquake sends an undersea shock wave across the ocean. Minutes later, thousands of miles away, that shock wave, called a tsunami, crashes into shore.The explanation for the forces that unleash killer tsunamis, massive earthquakes, and exploding volcanoes, lies in tectonic plates. These are the huge rock plates underneath the continents. What can happen when tectonic plates move a few centimeters? A. The atmosphere can become cooler. B. Whole continents can move. C. The ozone layer can thicken. D. The moon can move closer to Earth.