Tsunami

• Destroy ecosystems

  1. Floods huge areas of coastal wetlands and forests, damaging habitats

  2. Large amounts of debris carried in by the waves can pollute these areas, damaging ecosystems and killing wildlife
• 2011 Tohoku, Japan earthquake (M-9.0) triggered a tsunami up to 40m in height, destroying homes and infrastructure. The tsunami waves carried debris inland, flooding and polluting large areas of land. The coastal city of Sendai suffered extensive damage and many of its population were killed. Around 70,000 pine trees were knocked down, resulting in forest and biodiversity loss. The tsunami also hit the Pacific islands, devastating ecosystems. Entire bird nesting sites were lost, and more than 100,000 Layson Albatross chicks were killed, along with thousands of fish washed ashore where they suffocated
• 2004 Indian Ocean Tsunami, triggered by a 9.1 Mw undersea earthquake near Sumatra Indonesia triggered a tsunami that affected 11 Indian Ocean countries from Indonesia to Somalia, resulting in more than 230,000 people killed and entire coastlines and habitats destroyed
• Destroyed properties and infrastructure

  3. Fast moving water and the large amounts of debris carried in by the waves can sweep away buildings and infrastructure, destroying them
• Disrupt services

  4. Fast moving waters and the large amount of debris carried in by the waves can disrupt electricity and communication cables, disrupting the supply of these services

  5. Fast moving water can sweep away roads and railways, making it difficult to rescue people or supply emergency aid
• Cause injuires and fatalities

  6. Sweeping waters can drown people

  7. Large amounts of debris carried in by the waves can hit and kill people
• Tsunamis can travel over thousands of kilometres and devastate huge areas of coastline
• Tsunami occurrence

  1. An undersea earthquake causes the seabed to be displaced

  2. A large volume of water is lifted, forming waves of great wavelength and low height of less than 1 metre

  3. The waves travel towards land at high speeds around 800km/h

  4. On approaching the coast, greater friction with the shallower seabed slows the waves down

  5. The waves get closer together and increase in height. Waves can reach up to a height of 15mm or more, travel at speeds of 30-50km/h and devastate shorelines
• Tsunami

  A series of ocean waves which can be caused by undersea earthquakes
• Before a tsunami occurs

  The sea may recede from the shore because the sea water fills in the void caused by displacement of the seabed