To What Extent Are Secondary Effects the Most Hazardous Aspects of Tsunamis? Essay Example
To what extent are secondary effects the most hazardous aspects of tsunamis? Tsunami s are a series of giant sea waves created when a large volume of a body of water, such as an ocean, is rapidly displaced. Earthquakes, volcanic eruptions and other underwater explosions, landslides, asteroid impacts, and other mass movements above or below water all have the potential to generate a tsunami. Due to the immense volumes of water and energy involved, the effects of tsunamis can be devastating. Their hazards can be split into primary and secondary effects. Primary effects are the immediate effects of a hazard impact whereas secondary effects are the after-effects that occur as a result of the hazard and can be present for a long time, as the problems do not stop when the hazard event is over. The primary effects of a tsunami involve a loss of life and the destruction of buildings and infrastructure. They are a direct result of the waves and can be split into three main types. Hydrostatic effects involve objects such as boats and vehicles, and structures such as wooden buildings, being lifted and carried inland by the wave. The backwash or rundown, of the wave may have a similar effect, carrying objects offshore. Hydrodynamic effects involve the tearing of buildings apart, the washing away of soil and the undermining foundations of buildings, bridges and harbour structures. Finally shock effects involve objects be battered by debris carried in the wave. The human deaths therefore result from victims being drowned as they are lifted and battered, or hit by moving debris. The secondary effects of a tsunami involve both a loss of life and long-term economic problems. Tsunami waves can lead to long-term coastal flooding which in turn can lead to the spreading of water borne diseases such as cholera. The drinking of contaminated fresh water supplies can therefore lead to widespread loss of life through dehydration caused by diarrhoea. The spread and severity of disease