Surface Wave

Surface or ground waves can be of mechanical or electromagnetic nature. In physics, a surface wave is a mechanical wave that propagates along the interface between differing media, usually two fluids with different densities. A surface wave can also be an electromagnetic wave guided by a refractive index gradient. In radio transmission, a ground wave is a surface wave that propagates close to the surface of the Earth.

Read more about Surface Wave:  Mechanical Waves, Electromagnetic Waves

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