Text and Images from Slide
12.7 How do we know ... that plates move in real time?
- Relative motion describes the direction and speed of one plate compared to another, whereas absolute motion describes the actual velocity of a plate.
- GPS satellites provide real-time tests of plate motion by repeatedly surveying locations on Earth's surface.
- GPS data show that predicted motion values compare well with absolute values, but also show that the nonrigid characteristics of plates can produce wide boundary zones rather than narrow, discrete borders proposed by theory.