Tsunamis1 are unique in their destructive power, but they share many features with other ocean waves. Learn how the two wave types differ, and how ocean waves of all kinds affect New Zealand’s coast.
Ocean waves are a powerful force2 in the lives of New Zealanders. We like to surf them and swim in them – yet we are also vulnerable to the power of ocean waves. In particular, coastal New Zealand is at high risk of severe flooding by a tsunami3.
Several tsunamis – particularly those in South-east Asia (2004), Sāmoa (2009) and Japan (2011) – have focused attention on the destructive power of these waves. New Zealand researchers are actively working to understand how a large tsunami would affect our coast. Find out more about the work of:
- Dr Rob Bell – NIWA researcher, specialising in ocean waves, including storm surges and tsunamis, with a particular interest in sea-level changes
- Dr Richard Gorman – NIWA researcher, focused on waves, numerical modelling and wave forecasting
- Dr Te Taka Keegan – university lecturer with resarch interests in traditional navigation, Māori language technologies, indigenous4 language interfaces and multilingual usability.
- Dr Willem de Lange – Earth sciences university lecturer involved in numerical modelling, coastal processes and climatic hazards and tsunami research.
Key science concepts
For all their destructiveness, tsunamis share many features with surf waves and other water waves. In fact, waves of all kinds (such as water waves, sound waves and electromagnetic radiation5) share several fundamental characteristics that can help us understand why they behave the way they do. Waves transfer energy and shoaling converts the kinetic energy6 in a tsunami wave into potential energy. Shoaling is one reason why tsunamis cause so much damage to coastal areas.
Use a tsunami lens to learn more about the nature of science7. Dr Willem de Lange gives his personal insights about scientific inquiry and what it means to 'do science'. Then check out some of the measuring instruments Willem and others use when observing the natural world.
Take up the challenge
Student activities include:
- using a Mexican wave to demonstrate how waves transfer energy and to help your students visualise the wave behaviours of reflection8, constructive interference9 and shoaling.
- using an interactive or paper-based Venn diagram to illustrate the key similarities and differences between tsunami waves and surf waves.
- using a shallow tray of water to demonstrate wave generation and behaviour.
- creating a model to demonstrate the connection between volcanic eruptions and tsunami waves.
- the Connected article The tsunami that washed time away tells the story of two geologists who find evidence10 to explain the strange occurrence of ocean pebbles on Northland clifftops, try the learning activities in the teacher support materials.
Useful links
News article about how ancient tsunami have been mapped in a new interactive project. The New Zealand Palaeotsunami Database was compiled from old records by the National Institute of Water and Atmospheric Research (NIWA).
The Ocean Today website has a series of videos on tsunamis from the National Oceanic and Atmospheric Administration (NOAA).
- tsunami: A series of massive waves generated in the ocean usually by earthquakes, volcanic eruptions or submarine and coastal landslides, but they can also be caused by the impact of meteorites from outer space.
- force: A push or a pull that causes an object to change its shape, direction and/or motion.
- tsunami: A series of massive waves generated in the ocean usually by earthquakes, volcanic eruptions or submarine and coastal landslides, but they can also be caused by the impact of meteorites from outer space.
- indigenous: Originating and living or occurring naturally in an area or environment. People who are the original inhabitants of an area, or their descendants.
- radiation: Energy that is transmitted (radiates) from a source in the form of rays or waves or particles.
- kinetic energy: The extra energy of an object that it possesses due to its motion.
- nature of science: The Nature of Science (NoS), is an overarching and unifying strand of the New Zealand science curriculum. Through it, students develop the skills, attitudes and values to build a foundation for understanding the world around them – understanding how science works in order to make links between scientific knowledge and everyday decisions and actions.
- reflection: 1. The change in direction, or bouncing back of a wave when it strikes a surface. 2. Mirroring. 3. Casting back, as in light or heat.
- interference: The simultaneous presence of two or more waves in the same position, resulting in a new wave pattern.
- evidence: Data, or information, used to prove or disprove something.
