Answer:
a circle on the surface of a sphere which lies in a plane passing through the sphere's centre. As it represents the shortest distance between any two points on a sphere, a great circle of the earth is the preferred route taken by a ship or aircraft.
Answer:
The boundaries where the tectonic plates meet are the areas of the world with the most violent natural earthquake activity. When the plates grind against each other along plate boundaries, the rocks are under so much pressure that sometimes they heat up and fold, creating mountain ranges, hills and valleys.
