How do waves change as they approach the shore?
A. The height of the waves decreases
B. The distance between crests decreases
C. Friction acting on the top of the wave increases
D. The wavelength increases.
A. The height of the waves decreases.
As waves approach the shore, they undergo a process known as shoaling.
This is because the water becomes shallower as the waves approach the
shore, causing the wave base to slow down and the top of the wave to be
pushed up. As a result, the height of the wave increases, and the distance
between the crests decreases.
Furthermore, the friction of the seafloor causes the lower part of the wave to
slow down more quickly than the upper part, causing the wave to "break" and
resulting in whitecaps at the top of the wave. This process also causes the
energy of the wave to be dissipated, reducing the height of the wave further.
Therefore, the correct answer is A. The height of the waves decreases.