I have already discussed in a previous post about Atlantic tsunamis but I never really discussed the ways in which tsunamis are created. I have always been curious about this subject because it seems they just come out of no where. It seems that the news always has another story of a tsunami effecting a third world country. Tsunamis are one of the biggest natural disasters that effect humans. This is a huge problem for third world countries because they are unable to cope with the effects of the devastation. The fact of the matter is that these countries are not able to afford proper warning systems for their citizens. Therefore, they are not able to know that they are in danger until minutes before the wave hits.
This of course leads us to wonder what is the cause of these travesties? We learned in geology about the different subduction zones on the earth. As I have come to find this is one of the major causes of tsunamis. For those of you who do not quite remember what this is a subduction zone is due to an oceanic plate being forced down under an overriding plate into the mantle by plate tectonic forces. What specifically causes a tsunami is the friction that causes the two plates to be stuck. When this is the case the friction builds up and creates pressure like that of a compressed spring. This pressure can build up over years and even centuries. All the energy is stored in an overriding plate. Eventually when there is too much pressure built up for the plate to handle it snaps back into place. Essentially this movement is the cause of a tsunami. The plate goes forward shoving the water in front of it forward as well. The movement of the plate also lowers the inland areas. The waves rush in two different directions. One is towards the inland which of course has just been lowered so the water floods towards that area. The other goes towards the ocean basin. The wave travels very swiftly across the open ocean and last for hundreds of miles. One tsunami that occurred from an earthquake off the coast of Chile traveled across the Pacific Ocean all the way to Japan. One point to be noted about tsunamis is that they are not just one giant wave but a series of several waves. These are usually small waves that are followed by a series of much larger waves.
Tsunamis are one of the few disasters that we still do not have much control over. With more understanding of the disasters hopefully we will be able to better prepare for them.