# How do tsunamis move?

Tsunamis travel approximately 475 mph in 15,000 feet of water. In 100 feet of water the velocity drops to about 40 mph. Did you know…A tsunami travels from the central Aleutian Islands to Hawaii in about 5 hours and to California in about 6 hours, or from the Portugal coast to North Carolina in about 8.5 hours.

Sound waves, radio waves, even “the wave” in a stadium all have something in common with the waves that move across oceans. It takes an external force to start a wave, like dropping a rock into a pond or waves blowing across the sea. In the case of tsunamis, the forces involved are large — and their effects can be correspondingly massive.

How do tsunami waves change as they move?

A tsunami is made up of a series of very long waves. The waves will travel outward on the surface of the ocean in all directions away from the source area, much like the ripples caused by throwing a rock into a pond. As the waves approach the coast, their wavelength decreases and wave height increases.

Why do the waves of a tsunami move forward?

A tsunami is a series of extremely long waves caused by a large and sudden displacement of the ocean, usually the result of an earthquake below or near the ocean floor. This force creates waves that radiate outward in all directions away from their source, sometimes crossing entire ocean basins.

## How does the size of a tsunami affect its speed?

When the tsunami moves into shallower water, however, its enormous energy is concentrated within a smaller volume. This yields waves of greater height and slower speed. However, the speed of the wave is still much faster than a human can run. The contours of the sea floor and the coastline greatly influence the tsunami wave.

The tsunami’s energy flux, which is dependent on both its wave speed and wave height, remains nearly constant. Consequently, as the tsunami’s speed diminishes as it travels into shallower water, its height grows. Because of this shoaling effect, a tsunami, imperceptible at sea, may grow to be several meters or more in height near the coast.

## How do tsunamis differ from other types of water waves?

If you read the ” How do tsunamis differ from other water waves?” section, you discovered that a tsunami travels at a speed that is related to the water depth – hence, as the water depth decreases, the tsunami slows.

The next thing we wondered was, what is the difference between ocean waves and tsunami waves?

I discovered an ocean wave is not moving water, but energy that is passing through water. The water particles do not move, but they transfer energy to the next particle of water. In deep water, a tsunami’s energy is mostly located below the sea surface and the wave height is just a couple of meters.

## How long does a tsunami wave travel?

The displacement in a tsunami creates a wave which is very long – up to 200 km ( 125 miles ). These waves travel in a very predictable way that is determined by the water depth.

If you are at the beach, immediately move inland or to higher ground. If your boat is in deep water and offshore, maintain your position. If your boat is berthed or in shallow water, secure your vessel and move inland or to higher ground. If you are on the coast and cannot move inland, seek shelter in the upper levels of a stable building., and more items.

Yet another inquiry we ran across in our research was “How many miles per hour does a tsunami go?”.

With wave speeds that can reach as much as 435 miles per hour, a tsunami can travel as far inland as 10 miles, depending on the slope and the shape of the shoreline that it is traveling across. Ships traveling in the deep ocean may pass over a tsunami and not even notice it because a tsunami can cause the waves to be as little as 2 feet high where the water is very deep.