4. Next discuss how Dr. Knappe used technology to measure how fast the tectonic plates are

moving apart. What devices did she use?

She used the Global Positioning System.

Explanation:

The Global Positioning system sends the signal to the ground station via satellite. Through this, the distance between the ground station and the satellite is measured. That's how the movement is measured. If the tectonic plate moves a little bit, the distance will be changed. That's how Dr. Knappe measured the movement of the tectonic plates.