Direction: Read the following information carefully and answer the given questions
A tsunami is a powerful series of waves caused by a disturbance underwater. This is usually an earthquake under the sea. The waves travel through the ocean and cause devastation when they reach land. Humans are often killed and buildings destroyed when the water hits the coast. Tsunami is a Japanese word meaning 'harbour wave' that refers to a series of large ocean waves that hit a shoreline. The word originates from Japan because this is the country where tsunamis are most common. Most earthquakes that generate tsunamis occur in areas called subduction zones, where pieces of the Earth's crust press against each other.
Subduction means that one tectonic plate slides beneath another and sinks deep into the Earth's mantle. The friction between two slow-moving plates of the Earth's crust creates vast amounts of seismic energy which is released in the form of an earthquake. When a strong undersea earthquake strikes a relatively short distance below the sea floor, it abruptly pushes up one of the immense plates of the Earth's crust. That suddenly displaces an enormous amount of ocean water which becomes a tsunami, spreading outward in every direction from the epicenter of an earthquake - like ripples on a pond, only on a much larger scale. Tsunamis are not a single wave but "wave trains" consisting of multiple waves. The moving wave begins travelling out from where the earthquake has occurred. These tsunami waves may be as long as 100 km and travel across the ocean at speeds of up to 800 kmh. There may be a constant stream of waves that batter the shore for between 10 and 60 minutes. Tsunamis are also known as tidal waves, due to their large and powerful nature. The deadliest Tsunami recorded in the human history occurred in Indian Ocean in Sumatra, Indonesia.