How Waves are Formed

Waves are natural phenomena best described as a form of movement through a medium such as a liquid, semi-solid or elastic and even air. Wave movement will often be characteristic of transference of energy such as a radio wave that passes through the medium of air without displacing air particles, and waves energy will easily pass through solid objects.

Seawater waves are formed by water displacement due to seabed movement or undersea earthquakes, by strong and opposing ocean currents or by wind movement across the water surface. Wind energy is transferred into movement that ranges from small ripples caused by a light breeze through to waves of monstrous dimensions powered by the fury of a tropical storm. Once in motion, wave movement will travel with very little loss of energy in open water until resistance changes the shape and begins to slow the wave disproportionately. As the seabed begins to shallow, the lower part of the wave starts to lag and the top begins to mound up until a tipping point produces the signature curl and white water crash characterising surf rolling to the shore.

A mechanical wave is induced by some kind of disturbance, vibration or energy source. On November 7 in 1940, the Tacoma Narrows Bridge in Washington began to vibrate until resonant wave energy accumulated with sufficient force to shake the bridge 8.5 meters (28 feet) up and down wind was the energy source. This accident stands testimony to the energetic behaviour of a mechanical wave in certain conditions.

Other waves include radio waves, electromagnetic radiation and gravitational waves however irrespective of it’s nature, waves are characterised as longitudinal or compression (oscillations in a fixed position along which energy transfer occurs). Standard and measurable properties and descriptions include wavelength, amplitude (height), frequency, period, crest and trough.

Whether you are describing the formation of ocean waves or not, the basic principles are common, and the cause requires some form of energy source in order to set a wave in motion.