The law of superposition is a statement that says rocks on the bottom are always older than the top and the top is always younger than the one on the bottom... It is used to tell which rock layer or fossils are older/younger..
Hope that helps..Im not very good at explaining things..
There are a lot of differences between Magnitude and Intensity.
Magnitude is used to measure the energy that is released during an earthquake.
Intensity is used to measure the strength of shaking that is produced by an earthquake at a certain location.