05:54
World in Motion: Heat, Convection and Plate Tectonics
Most scientists believe heat and convection probably play a major role in plate tectonics. And, yet, many questions remain.
01:54
World in Motion: Understanding Earth's Interior
Many scientists believe the plate tectonics process begins deep within the Earth. The challenge is to gather reliable data about an area that no one has ever actually explored--at least not directly.