Tsunamis happen very often in many places all over the world. Some causing big impact to the people there some causing small impact only. There are many reasons why a tsunami happens. Here are some geographical causes:
- When the earthquake hits, energy is transferred and the displaced water forms a wave. As the wave travels and enters the coastal area, it begins to increase in amplitude and the tsunami occurs.
- When a land-based volcano break down and collapse, It forces large amounts of ash and debris into the water. This sudden change and displacement of the water column transfers to kinetic energy and results in waves. As these huge waves enter the coastal areas, the tsunami occurs.
- Another way tsunami can occur is by submarine volcanoes, these volcanoes are underwater. Once these volcanoes collapse downwards or spew forth lava heating the surrounding water quickly. Through these, the hot water will be pushed upwards as hot water is less dense than cold water. These huge movement of the water can cause tsunami.
Land- Base volcano
- There is a case in 1958 where a tsunami was caused by rockfall in Lituya Bay, Alaska. In this case, a gigantic boulder was loosed by an earthquake and fell into the bay causing a tsunami that went out to sea.