Please try again later. Ahmed Rashid, former Pakistani revolutionary, journalist and an expert on Taliban, explains why Pakistan is in a such a mess. He lists the factors that led Pakistan to the situation it is in right now.lease try again later. Ahmed Rashid, former Pakistani revolutionary, journalist and an expert on Taliban, explains why Pakistan is in a such a mess. He lists the factors that led Pakistan to the situation it is in right now.
Body waves travel through the interior of the Earth. On the other hand, surface waves propagate only at the interface between two different media, like the interface between Earth and atmosphere (i.e. the surface of the Earth).Body waves are of two types: Primary waves (also called P-waves, or pressure waves) and Secondary waves (S-waves, or shear waves).n the other hand, surface waves propagate only at the interface between two different media, like the interface between Earth and atmosphere (i.e. the surface of the Earth). Body waves are of two types: Primary waves (also called P-waves, or pressure waves) and Secondary waves (S-waves, or shear waves).
Body waves are of two types: compressional or primary (P) waves and shear or secondary (S) waves. P- and S- waves are called body waves because they can travel through the interior of a body such as the Earth's inner layers, from the focus of an earthquake to distant points on the surface. The Earthâs molten core can only be travelled through by compressional waves.