Explain how a tsunami is formed.

At a tectonic plate boundary, a earthquake occurs. This causes a large release of pressure and a tectonic plate to jolt upwards, causing a water displacement column. As a result, waves with a low frequency, low amplitude and a long wavelength ripple out in all directions. As these waves begin to get closer to the shoreline, friction with the sea bed begins to increase causing the wave to slow down. Whilst friction levels increase, the wave length shortens, the wave amplitude increases. Eventually the wave gets to such a height it breaks, thus causing a fully formed tsunami.