In scientific terms and most used by the surfing community around the world, the wave height is measured vertically from the trough to the crest and is known by surfers as face scale. In Hawaii, local surfers use the back of the wave to measure wave height and is called Hawaiian scale or local scale.

The vertical distance between the crest and the trough is the wave height. The horizontal distance between two adjacent crests or troughs is known as the wavelength.

amplitude

Scientists use two measures to describe ocean waves: height and length. As is shown on the figure, wave height is defined as the height of the wave from the wave top, called the wave crest to the bottom of the wave, called the wave trough.

Waves are most commonly caused by wind. Wind-driven waves, or surface waves, are created by the friction between wind and surface water. As wind blows across the surface of the ocean or a lake, the continual disturbance creates a wave crest. The gravitational pull of the sun and moon on the earth also causes waves.

Wave Crest: The highest part of a wave. Wave Trough: The lowest part of a wave. Wave Height: The vertical distance between the wave trough and the wave crest. Wave Length: The distance between two consecutive wave crests or between two consecutive wave troughs.

Explanation: Long waves, also called infragravity waves, have a wave period of 30 seconds to several minutes. Astronomical tides represent one important example of long waves.

As the wave moves into increasingly shallow water, the bottom of the wave decreases speed. There comes a point where the top of the wave overtakes it and starts to spill forward — the wave starts to break. We’re surfing! In general a wave will start to break when it reaches a water depth of 1.3 times the wave height.

So the first wave in a group is tiny, the next one is bigger and so on until you get the biggest one in the middle of the group. Then they get smaller again. The last one is tiny, so the biggest wave in the group is in the middle, and if there are 14 waves in a group, the seventh wave is the biggest.

Wave height stores the energy as potential energy. As a wave enters deeper water the height and potential energy decrease. Therefore the speed of the wave must increase.

100 feet high

In shallower water near the coast, waves slow down because of the force exerted on them by the seabed. If a wave is approaching the coast at an angle, the nearshore part of the wave slows more than the offshore part of the wave (because it’s in shallower water). This is why the wavefront changes direction.

So, the frequency of the wave is 5 Hz.

The number of complete wavelengths in a given unit of time is called frequency (f). As a wavelength increases in size, its frequency and energy (E) decrease. From these equations you may realize that as the frequency increases, the wavelength gets shorter. As the frequency decreases, the wavelength gets longer.

Why shoaling happens: waves get slower, shorter and higher Shoaling happens because waves experience force from the seabed as the water gets shallower. This slows down the wave – the shallower the water, the slower the wave. In deep water, a tsunami moves very fast and has a long wavelength and a small amplitude.

Lituya Bay

500 mph

The energy of the tsunami runs through the entire depth of the ocean. It only becomes deadly when the ocean floor becomes shallow, and all that energy compresses into a smaller amount of water. Once it reached land, the raw energy of thousands of tons of water destroyed everyone and everything in its path.

The largest likely tsunami to hit New York City in any scenario would be about 100 feet in height. That would flood most of Manhattan, but would be unlikely to collapse very many buildings, and if given enough warning, people could climb up several stories to save themselves.

Especially skyscrapers, because those foundations are very strong. There would be a lot of damage, and small buildings would be destroyed, but the larger buildings would survive. Look at other areas hit by tsunamis. The large buildings survive.

20 miles