Tsunami Quiz: Tsunami Awareness Quiz For Students

A passing train: People who have experienced a tsunami approaching described the sound as being similar to a freight train.

All of the Signs: The sea moving back from the beach, a roaring sound, and shaking of the ground are all signs of an approaching tsunami.

Underwater earthquakes: Although volcanic eruptions and landslides do sometimes cause tsunamis, most are caused by underwater earthquakes. The vertical movement of the seafloor displaces the column of water above. An underwater earthquake caused the 2011 tsunami in Japan and the 2004 Indian Ocean tsunami.

The wavelength is the distance between peak to peak or trough to trough of the wave.

Harbour wave: The English word “tsunami” comes from the Japanese term for “harbour wave”. Tsunamis are not the same things as tidal waves and actually consist of a series of waves.

False: A bigger tsunami does have more energy to cause destruction. However, the impact of a tsunami also depends on the shape of the shore, how much land it inundates, and what is on that land. The Japan tsunami, at 15 meters in height, killed 22,000 people and caused the Fukushima nuclear disaster. By comparison, the much larger 1958 Alaskan tsunami had a small impact on the people in terms of deaths. Even the waves created by the 2004 Indian Ocean tsunami were much smaller than the Alaskan tsunami, despite damaging the coastlines thousands of kilometers away as far as Africa.

Water depth: The deeper the water, the longer the tsunami’s wavelength and the faster it travels. Tsunamis in the open ocean travel at fast speeds (805 km/h), but are so low they can be ignored by planes and ships. As the tsunami moves to shallow water, its front slows down but its rear continues at the original speed. This means the water bunches up quickly, and the tsunami wavelength becomes much shorter. At this point, the wave can grow by meters in height. This is known as “shoaling”.

The 1958 Lituya Bay tsunami in Alaska: The Lituya Bay tsunami in Alaska, which was caused by a landslide falling into a fjord, produced the largest waves ever seen. It flattened trees up to 500 meters above sea level. However, this tsunami is regarded as an unusual event.

Pacific Ocean: About 80 % of tsunamis begin within the Pacific Ocean’s Ring of Fire. This is a very geologically active area. Tectonic shifts in this zone make volcanoes and earthquakes common.