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.
02:05
World in Motion: Earthquakes and Plate Tectonics
With the advent of plate tectonics, it's become apparent that episodes of extreme geologic upheaval--like earthquakes--are much more than simply random events.