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.
Compressional or P (for primary)
, Transverse or S (for secondary)
, Love, and Rayleigh. Primary waves push and pull the ground in the direction the wave is traveling. Secondary waves travel in the same direction, but they shake the ground back and forth perpendicular to the direction the wave is traveling. Love waves move back and forth horizontally. Rayleigh waves cause both vertical and horizontal ground motion.