As the tsunami crest approaches shore____________.

Correct option is C

As a tsunami crest approaches the shore, the period of the wave remains constant, its velocity drops, and the wave height greatly increases. This is due to the interaction of the tsunami wave with the shallower ocean floor near the coastline. As the water depth decreases, the tsunami slows down, but the energy of the wave is compressed, causing the wave height to rise significantly.
Information Booster:
· Tsunami waves have long wavelengths and travel at high speeds in deep water.
· As they approach shallow coastal areas, their speed decreases, but the wave height increases dramatically due to the reduction in depth.
· The period of the wave (the time between two consecutive crests) generally remains constant, meaning the energy is concentrated in a smaller area as the wave slows down.
· This process leads to the characteristic large waves associated with tsunamis when they make landfall, which can cause extensive damage.