TsunamisA tsunami is a series of ocean waves with very long wavelengths caused by large-scale disturbances of the ocean, such as; earthquakes, landslide, volcanic eruptions, explosions and meteorites. Tsunami is a Japanese word with the English translation: "harbour wave". In the past, tsunamis have been referred to as "tidal waves" or "seismic sea waves".
The Ring of Fire is a string of volcanoes and sites of seismic activity or earthquakes, around the edges of the Pacific Ocean. Almost 80 percent of tsunamis occur within the Pacific Ocean’s ‘Ring of Fire’. This is due to the amount of earthquakes and volcanic activity in the area, which occur due to the tectonic shifts in the earth’s plates. |
The Boxing Day tsunami |
The Boxing Day tsunami in 2004 is believed to be the deadliest tsunami in history, killing more than 230,000 people across 14 countries.
It began at 7:59am (local time) on December 26, 2004, when a 9.1-magnitude earthquake struck off the northern tip of Sumatra in Indonesia. Scientists say the earthquake was the third-biggest ever recorded, lasting up to 10 minutes and causing the Earth to vibrate up to one centimetre. It also displaced an estimated 30 cubic kilometres of water, unleashing a massive tsunami across the Indian Ocean. More than 1.7m people were left homeless/displaced after the destructive tsunami. |
Reducing the death toll from tsunamis |
As a direct result of the tsunami generated off the coast of Indonesia on 26 December 2004, the Australian Government identified the need to be able to warn the Australian population of such phenomena, with the aim of decreasing the loss of life and the economic impact on its population. At that time an informal Australian Tsunami Alert System (ATAS) was operated jointly by the Bureau (Australian Bureau of Meteorology), GA (Geoscience Australia) and AGD (Attorney-General's Department ). The ATAS system had limited capabilities in tsunami monitoring and warning.
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