Question

A scientist is studying how large tsunamis form. The scientist uses the following model to examine the properties of large tsunamis. They know that tsunamis, or ocean waves with a very large wave amplitude, happen after another event, such as an earthquake or landslide has dramatically shifted the earth’s crust and therefore the water above that crust. While it is difficult to see the amplitude and wavelength of the individual waves while they are far out at sea, we can see how large they are as they get into shallower areas as they approach the shoreline. Based on the model and explanation, how does an earthquake cause tsunamis?

A. An earthquake’s seismic wave provides mechanical energy to the ocean. As energy is added the amplitude of the wave is increased.
B. As the earthquake vibrates more waves are created. More waves means that there is less space between them decreasing the wavelength. Because amplitude is inversely related to wavelength, this means that the waves must be less energetic.
C. As the earthquake creates more waves the frequency is increased. Because amplitude is directly related to frequency, the amplitude is also increased.
D. An earthquake’s seismic waves overlap and build upon each other as the earth continues to shake. As the earth shakes more, the amplitude of the wave increases.

Answer 1

An earthquake transfers mechanical energy to the ocean, creating a tsunami with larger amplitude waves as they approach shallower coastal waters.

Step-by-step explanation:

An earthquake can generate a tsunami by causing a large displacement of the seafloor, which transfers a significant amount of energy to the ocean water above it. This energy transfer results in a series of waves with long wavelengths. The model described indicates that the amplitude of these waves is related to the energy imparted by the earthquake's seismic activity. As the waves travel into shallower coastal waters, their speed decreases, the waves compress, and the amplitude increases, making the tsunamis more visible and powerful as they approach the shore.

A correct answer to the model provided would be: An earthquake's seismic wave provides mechanical energy to the ocean. As energy is added, the amplitude of the wave is increased (Option A). This is because the amount of energy in a wave is directly proportional to its amplitude squared, which leads to larger ground displacements and the potential for significant coastal damage when these waves reach the shore.