How does a tsunami form and why do their waves increase in size as they approach the shore?

This question is initially asking for the understanding tsunami formation process. It would be useful to provide a brief definition of a tsunami, so the examiner knows you have a clear idea of what a tsunami actually is. This should be followed by the description of tsunami formation. To get all the available marks, the answer should provide more explanation into the physics of tsunami waves as they approach the shore. Try to use key words such as shoaling and energy flux as this will make it easier for the examiner to know where to give the marks. My answer would look like this:A tsunami is best described as a number of waves created from the disturbance of the Earth’s crust or from water that is displaced from underwater volcanic eruptions. This results in the creation of larger than normal waves with a greater amount of energy reaching the shoreline. The earth’s surface, including the ocean floor is made up of a number of tectonic plates, in the form of oceanic and continental plates. When an oceanic plate subducts beneath a continental plate, pressure builds up. When this pressure exceeds the maximum energy capacity of the ocean floor, the pressure is released as seismic energy, jolting the ocean bed, causing an underwater earthquake. As the ocean floor suddenly moves, there is displacement of the water above. The water level above the site of the underwater earthquake is raised. Gravity pulls the water level back down, causing the energy to ripple on the ocean surface horizontally away from the earthquake site in the form of tsunami waves. The energy flux in the waves remains constant at all times, thus as a tsunami wave reaches inland, increased friction causes the wave to slow down. However for the energy flux to remain the same, the wave needs to grow in height (called shoaling).