1. Landslides involve the movement of a mass of rock or sections of the Earth’s crust under the force of gravity.
2. They can be triggered by natural causes like heavy rainfall saturating the soil, vibrations from earthquakes or undercutting of banks and cliffs from waves or rivers.
3. Construction of roads and railways on hillsides along with building works can weaken hillsides and make them more vulnerable during heavy rainfall. Mining activities also contribute to the hazard.
4. They are measured in magnitude.
5. The causes of earthquakes in Australia is intra-plate tension where movements occur along cracks and faults in the Earth’s crust.
6. Every 15 months Australia experiences earthquakes of 5.5.
7. 13 people died and over 120 people were injured. It also impacted on buildings.
8. Landslides are movements on the Earth’s crust and earthquakes are movements below the Earth’s crust.
9. The movement of the ocean bottom displaces water on the surface, forming a tsunami.
10. When an earthquake, landslide or volcano occurs under the sea it can trigger a tsunami.
11. Sudden shifting of continental plates cause earthquakes, forcing sea water above to rise, forming waves.
12. Shake, Drop and Roar are the three main signs.
13. A earthquake measured 9.3 caused the tsunami.
14. There are 23 earthquake monitoring stations in Australia.
15. The wave slows down as it enters shallow water.
16. The United Nations a tsunami warning system for the Indian Ocean.
17. Ted Bryant a Wollongong University geoscience professor, studies natural hazards and has warned that tsunamis triggered by New Zealand’s alpine fault line could strike NSW as often as once every 500 years.
18. A) 10S 100E
B) i)
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