What causes tsunamis to travel at high speeds?

Tsunamis travel at high speeds due to the movement of the entire water column, from the ocean surface to the seafloor. Unlike surface waves, which only affect shallow layers, tsunamis carry massive energy throughout the water column. In deep oceans, they can reach speeds of up to 800 km/h. As they approach shallower coastal areas, their speed decreases, but their height increases, making them highly destructive.