Tsunami
"series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean"
- AKA seismic sea wave
- Tsunamis are waves generated by the tremors and not an earthquake in itself
Causes:
- Earthquakes - occur only if - epicentre below oceanic waters + high magnitude
- volcanic eruptions
- Other underwater explosions (including detonations of underwater nuclear devices),
- landslides,
- Glacier calving,
- Meteorite impacts and
- Other disturbances above or below water all have the potential to generate a tsunami.
Characteristics:
- Generated by the displacement of water.
- wavelength is far longer.
- consist of a series of waves with periods ranging from minutes to hours, arriving in a so-called "internal wave train”
- Wave heights of tens of meters can be generated by large events.
Impact:
- limited to coastal areas
- Can also affect entire ocean basins
The 2004 Indian Ocean tsunami was among the deadliest natural disasters in human history with at least 230,000 people killed or missing in 14 countries bordering the Indian Ocean.