Teodora's science blog: Tsunami essay

Tsunamis – The devastating waves

By: Teodora Milenkovic 7B

February 25^th, 2011

Mrs. Medenica, Science

Tsunamis are devastating waves that can be lethal for many people, and are very destructive and dangerous. A tsunami is mostly described as a tidal wave that is caused by the movement of the Earth’s plates (an earthquake), under the Earth’s crust. Every earthquake has an epicenter, a point on the surface right above the earthquake’s focus, as well as a hypocenter, the exact point of the fault movement. Once seismic primary, secondary and surface waves start traveling underwater, they cause the creation of a wave that reaches great heights once it hits the shore. However, in the open sea, tsunami is very low, just around one meter. This is because it hasn’t gathered a lot of energy yet, and hasn’t grown a lot. Tsunamis are rarely felt by scuba-divers and ships in the open ocean. As the tsunami travels it can grow to a width of about 100 kilometers, and it can be as high as 30 meters! Once it comes to the shore, the tsunami has no more water to travel through, so it collapses, stopping many lives, and ruining the economy, culture and other important factors of one country. Before a tsunami happens, the water may move away from the shore for a little while, exposing the floor of the ocean. Once the tsunami hits, the first wave is usually not the largest one. Waves keep on coming every ten to sixty minutes, getting bigger and bigger. Tsunami is a natural disaster that has frightened many people, and that would most definitely really scare me if I was to experience it, and survive it.

Tsunamis happen all over the world, in major oceans, such as the Pacific, Atlantic, Indian and others. Around 70% of our planet is made out of water. However, there is an area where tsunamis seem to happen over and over again, and that is the Ring of Fire. The Ring of Fire is an area in the Pacific Ocean located around Australia, the east part of the Eurasian plate, as well as the West Coast of the Americas. This part of the ocean is around 40, 000 kilometers long. One of the deadliest tsunamis ever happened in Indonesia in 2004, and it completely destroyed a large part of that country. This is not very surprising, since Indonesia lies in between the Ring of Fire. Most earthquakes occur along the Ring of Fire because that is where most of the fault lines are, and where tectonic boundaries are located. Apart from the earthquakes, and tsunamis, many volcanic eruptions occur along the Ring of Fire, as well.

The most recent tsunamis happened in Mentawai, Indonesia in October of 2010, and on the Bonin Islands, in December 2010. The tsunami in Mentawai was caused by an earthquake that had the magnitude of around 7.7. That is extremely high, and this tsunami killed around 108 people, as well as causing around 500 to go missing. The tsunami that happened on the Bonin Islands, Japan, was cause by an earthquake that had the magnitude of 7.4, but the number of casualties is unknown.

Since tsunamis happen quite often, scientists found different ways to predict tsunamis, and help the people of the endangered area evacuate before it is too late. All tsunami warning systems consist of two components that are equally important. The first part is the actual sensors that detect the seismic activity, and the other component is the infrastructure of the alarms and communications, to warn the people of endangered areas that a tsunami is approaching. One of the most famous ways of seeing whether a tsunami is coming or not is by satellites, that can take an accurate picture of how far the tsunami is, and how long will it take until it reaches the shore. Then, the satellites can send the information to different tsunami warning facilities around the globe, including the PTWC, for the Pacific Ocean, and the Coordination Group for the Tsunami Early Warning and Mitigation System in the North Eastern Atlantic, the Mediterranean and connected Seas. Another warning system, that I think scientists should work on making, is a sensor-based system that would act like certain animals due. Some animals (like elephants) can detect seismic waves coming from the ground. Certain species of animals can hear sound waves outside of human range of hearing, and therefore can sense that something is wrong. In the 2004 tsunami in Indonesia, elephants went for the hills once they detected the seismic waves, because they knew that something abnormal is happening. Another type of warning system consists of The Regional Warning System, and The International Warning System. The Regional Warning System predicts whether there is going to be a tsunami by gathering the seismic information in that area, or place. Then, they warn the citizens through sirens. However, this is not always affective, because, just like in weather forecasts, there are a lot of fake alarms. The International Warning System gathers the information about seismic activity from other countries, to see whether a big tsunami is approaching.

Besides the many warning systems that are being developed right now, tsunamis cannot, unfortunately, be stopped and they continue ruining peoples’ homes, and killing their families. Most of the effects of tsunamis are long-lasting, and cannot be repaired over night. Besides the physical look of the cities that are hit by tsunamis, many more factors get very damaged, or even ruined in extreme cases. The tourism of the countries affected suffers terribly, because tourists do not want to come to a beach, and be afraid that a tsunami might kill them. They will choose to go to a safer place, where the risk of a tsunami is lower. Tsunami affects the overall health of the people, as well. From the water that the tsunami brings to the shore, many bacteria create, because of the humidity. This results in many skin-related illnesses, and sometimes even epidemics. The economy of the country is affected, as well, because the tsunami ruins much of it’s’ agriculture and infrastructure. Part of the culture gets wiped out sometimes, when historical artifacts and buildings collapse under tsunami’s pressure.

In conclusion, I can state that tsunamis are extremely dangerous, mostly because of the enrgy they carry with them, and the way they release that energy. One tsunami can have the power of even 30,000 atomic bombs. If it takes one atomic bomb to destroy a whole city, 30,000 bombs could surely wipe out a few countries. In the near future, I hope that scientists will also start coming up with more revolutionary ideas of how we stop tsunamis, or, at least, how we can make them less powerful. I also hope that they will continue working on the houses that can withstand a tsunami. If they keep improving this invention, less people will be left on the streets after the natural disaster.