What is true about the amplitude of a tsunami?

A- it increases in shallow water near the shore.

B- is is always lower in amplitude that a wave made by wind

C- it is high enough to topple ocean liner far out sea.

D- in deep water, it is 3 times higher than normal ocean waves.

A is true

To determine the correct answer, let's go through each option and find out the true statement about the amplitude of a tsunami.

A- The first option states that the amplitude of a tsunami increases in shallow water near the shore. This statement is true. As a tsunami approaches the coast, it moves from deep water to shallow water. In shallow water, the wave height increases due to the compression of the wave energy.

B- The second option claims that the amplitude of a tsunami is always lower than a wave made by wind. This statement is false. While it is true that wind waves are more common and generally have lower amplitudes compared to tsunamis, under certain circumstances, a tsunami can have much larger amplitudes than wind-generated waves.

C- The third option suggests that the amplitude of a tsunami is high enough to topple an ocean liner far out at sea. This statement is false. Tsunamis, although capable of causing significant damage near the shore, typically have relatively small amplitudes in deep water. They only become hazardous as they approach the coastline and the wave energy compresses.

D- The last option states that, in deep water, the amplitude of a tsunami is three times higher than normal ocean waves. This statement is false. Tsunamis have much larger wavelengths (the distance between two consecutive wave crests) than regular ocean waves, but their amplitudes are generally not significantly higher than normal waves.

Therefore, the true statement about the amplitude of a tsunami is Option A: It increases in shallow water near the shore.