Tsunamis
Tsunamis are a series of large waves that strike coastal areas. They can happen with little warning and result in flooding and damage to coastal communities. Thankfully, they are a rare event. Storm surges are more common. Residents, particularly those living in low-lying areas near the coastline, should prepare in advance.
What to do:
Tsunami facts
- Also see Marine geological hazards
- Tsunamis are a series of large waves caused by events such as submarine earthquakes, landslides, volcanic eruptions, and less commonly, meteoric impacts. Tsunamis can also occur in large lakes.
- They can occur with little warning in the ocean and in lakes.
- A tsunami can be triggered by a large, high energy, but relatively short duration disturbance of the sea floor. Such waves can travel across the ocean at high speed (800 km/h, the speed of a jet plane).
- As the tsunami waves approach the shoreline and water depth shallows, the wave speed slows, but wave height will increase as wave length decreases. In 20 m of water, wave speed will be 50 km/h.
- Tsunamis can occur as individual or multiple waves following each other by minutes and even hours.
- Tsunamis can grow to 60 or more metres in height (the size of a ten-story building).
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