Understanding Earthquakes Nature has the power that no human can

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Understanding Earthquakes Nature has the power that no human can control it. Even though we have the technology that people like to talk about and proud of it, we still can not stop the nature's anger. I called it anger of nature because it just kills people and causes large-scale damages, which is almost impossible to recover or it will be recovered in long-term, to social systems or property. Nature shows its anger in different ways, and we name these as natural disasters that are also called great global changes. Natural disasters can happen at any time or in any place, and it's impossible for us to know when it's going to happen and how much the damage is going to be. Each of them has a different power to damage the universe. Some of them are hurricanes, tornadoes, droughts, landslides, and earthquakes. Of all the destructive phenomena of nature, the earthquake is the most destructive, violent and frightening force.

In the past, the natural cause of earthquake was little understood. There were only a few descriptions of earthquakes recorded up to the 18th century. One of the most popular theories in that time was that air rushing out of caverns deep in the Earth's interior was causing an earthquake, but today this theory seems ridiculous. There were a lot of earthquakes that made big damages and killed many people, and again there were no possibilities to do something. According to an article called Historic Earthquakes: "the largest recorded earthquake in the world was a magnitude 9.5(mw) in Chile on May 22, 1960. More than 2,000 killed, 3,000 injured; 2,000,000 homeless, and $550 million damage in southern Chile." And also these damages continued in Hawaii because of tsunami which is caused by the earthquake, caused 61 deaths, and $75 million damage; $50 million damage in Japan, and also $500,000 damage to the west coast of United States. And again according to Historic Earthquakes "The world's deadliest recorded earthquake occurred in 1557 in central China. It struck a region where most people lived in caves carved from soft rock. These dwellings collapsed during the earthquake, killing an estimated 830,000 people." (http://soilslab.cfr.washington.edu/esc110/2001Spring/projects/073/historic.html) The cause of an earthquake is the sudden shifting of large sections of the earth's crust. There are plates that are parts of the lithosphere, which is made up the uppermost part of the mantle, and also made up of the crust. There is a constant pressure on these plates to move, and at the same time land masses being pushed together allows movement to start. And according to an article called earthquake in Natural Forces web page: these plates "form continents, others the ocean floor, but they are always moving. The core is made up of even hotter rocks below the mantle, and currents of burning rock rise up through the mantle. These currents spread out once they hit the bottom surface of the crust. This behavior tends to tear the crust, pulling the apart, grinding some plates against others, colliding them into one another. Continental drift (when major plates are slowly but steadily moved apart) also contribute, carrying plates until they collide. It is through these collisions that mountain ranges are also formed. This movement of our dynamic planet produces earthquakes and volcanoes." (http://library.thinkquest.org/C003603/english/earthquakes/thecauses.shtml?tqskip1=1&tqtime=1105) The most common cause of earthquakes is fault, which is a thin zone of crushed rock between two blocks of rock. Faulting can be any length that is from centimeters to thousands of kilometers. There are three kinds of faults such as normal fault, reserve fault, and strike-slip fault. According to an article in nature: "A normal fault drops rock on one side of the fault down relative to the other side." The second one is "a reverse fault one rocky block is pushed up relative to rock on the other side." And the third one is "Strike-slip fault that have a different type of movement than normal and reverse faults. Blocks move on either side of a reverse or normal fault slide up or down along dipping fault surface. The rocky blocks on either side of strike-slip faults, on the other hand, scrape along side-by-side." http://www2.nature.nps.gov/grd/usgsnps/deform/gfaults.html There are couple ways for us to know how a fault exists. For example; after an earthquake happens, there should be some kind of evidence that are left from the earthquake, and these can be surface raptures, and fault scarps. Another way to know is when a large earthquake breaks the fault, and the other way is the denser seismographic network because it records the small earthquakes that are created by the fault.

There are seismic stations in the denser seismographic network that measures the movement of the ground at the site. Earthquake releases energy, when the slip of one block of rock comes over another, and this energy makes the ground vibrate. Then the vibration pushes the adjoining piece of ground and causes it to vibrate as well, so the energy that comes out from earthquake travels into a wave. There are two kinds of waves that are created by an earthquake, and these waves are called surface and body waves. Surface waves travel along the earth's surface. According to an article in Earthquakes: "Surface waves travel along the surface of the earth, rather than down into the earth. Although they are the slowest of all the earthquake waves, L waves usually cause more damage than P or S waves." Body waves are vibrations that ravel through the Earth, and they are divided in two different waves called primary and secondary waves. Primary waves or P waves are the fastest waves. As the article in Earthquakes mentioned "P waves arrive at a given point before any other type of seismic wave. P waves travel through solids, liquids and gases. They move through the Earth at different speeds, depending of the density of the material through which they are moving. As they move deeper into the Earth, where material is more dense, they speed up. P waves are push-pull waves. As P waves travel, they push rock particles into the particles ahead of them, thus compressing the particles. The rock particles then bounce back. They hit the particles behind them that are being pushed forward. The particles move back and forth in the direction the waves are moving." Secondary waves, or S waves do not travel fast as much as P waves through the earth. According to article earthquakes "S waves arrive at a given point after P waves do. S waves travel through solids but not through liquids and gases. Like P waves, S waves speed up when they pass through denser material. S waves cause rock particles to move from side to side. The rock particles move at right angles to the direction of the waves." (http://www.germantown.k12.il.us/html/earthquakes.html) Earthquake has a very scary and unusual sound that surprises you out of your sleep. You don't understand what is going on because in that time you still feel sleepy. Suddenly, your house starts to shake, weird sounds coming out of your walls, small accessories start to fall from their shelves, and crash to the floor. And finally, if you are still alive, you realized that it's an earthquake that scares you to death, and the bad thing is you can not do anything about it. If it's not a strong one, then you are lucky, otherwise you will have some damages for sure or maybe you will die, or you will come across with the worst thing that is somebody who you love will die, and you will be just injured, and there is nothing you can do about it. All of the things that I just said are coming from what I experienced about three years ago. Earthquake happened in a city called Izmit, which is just 60 miles away from Istanbul, and it was three in the morning when everybody was sleeping. It took ninety seconds, and that ninety seconds felt like ninety hours. Luckily, nobody in my family died or injured, but generally there were a lot of death and homeless people in Izmit after the earthquake. There were more than twenty thousands of death people, and more than fifty thousands of people were homeless. Even though Turkish government tried to help people; it wasn't enough because it was an amazing tragedy that hit Turkey at an unexpected time.

It would be a great advantage to be able to successfully predict the earthquakes around the world because it would save countless lives and billions of dollars. Since the existence of earthquakes, people have been trying to predict earthquakes in different ways such as observing and cataloging everything from strange animal behavior to earthquake weather. The truth about this situation is helpless because there is no way we can predict an earthquake's time, magnitude, and also how many times it's going to happen.

There is no way for us to prevent earthquakes because they occur anywhere at any time, but there are possibilities that we can reduce the damage to the properties, loss of life and injuries by preparing ourselves. We can prepare our houses, work places, and also government can start programs that educate people about what to do during the earthquake, and how to get prepared for an earthquake.

As you can see earthquakes are one of the most destructive phenomena of nature. Unfortunately nothing can be done to prevent an earthquake; however, we must keep advancing in our technology to better predict these catastrophes. With improved abilities in predicting earthquakes much of the economic loss may not be prevented, but the loss of human life could certainly be reduced. Living through a horrific earthquake in 1999 only 60 miles from my home in Istanbul, Turkey, I have come to believe that loss of life is much more tragic than the economic loss.