Tsunmais Flashcards
What are tsunamis and how are they formed?
Tsunamis are the movement of energy through water. Tectonic plates slip releasing the energy into the water .It can travel in multiple directions and they move as fast as 500 mph. Wave shoaling occurs when it reaches the coast as there is less water for the energy to travel through so energy is compressed causing the wave to slowdown and increase in height.
What does the impact of a tsunami depend on?
1) Duration of the event
2)The wave amplitude, water column displacement and distance travelled.
3)The physical geography of the coast, especially water depth and gradient of the shoreline
4)The degree of coastal ecosystem buffer e.g mangrove and coral reef protection
5)The timing of the event and the quality of early warning systems
What happens as the tsnuami travels away from the epicentre?
The velocity decreases.
2004 Indian ocean Tsunami economic impacts
-60% of fishing fleet and industrial infrastructure was destroyed
-economies were devastated as relied on agriculture and fishing
-In Thailand the tourism industry lost about US$25million per month.
-Overall, economic costs came to US$10billion
-12,000 workers lost their jobs
2004 Indian ocean Tsunami social impacts
-In some coastal villages, 70% villagers died.
-Infrastructure was destroyed
-In Sumatra, 1500 villages were destroyed
2004 Indian ocean Tsunami environmental impacts
-Coastal settlements were destroyed.
-Most vegetation and topsoils were removed up to 800 metres inland
-Ecosystems damaged
-Fresh water supplies and agriculture soil were contaminated by saltwater
Tsunami DART system
1) DART tsunami buoy deployed into the ocean.
2)When an earthquake generates a tsunami, magnitude of the resulting tsunami wave is measured by the tsnuameter.
3)This is then transmitted via satellite to the tsunami warning centres to improve the accuracy of the tsunami forecast.
