How is a gps used in studying volcanic activity

GPS can precisely measure both horizontal and vertical motions. GPS and other instruments used to measure deformation may detect motion at a volcano before any earthquakes occur, and these changes in shape may accelerate immediately before an eruption, making GPS a valuable monitoring tool.

Iwolud you, but i dont know what you are asking.

The answer to this will be from your lab notes/procedure. it would be best to ask another student who participated in the lab as we do not know what was done, what enzyme or if the temperature is celsius or fahrenheit. if i were to guess though i'd say the rate stopped due to enzyme denturing at high temperature