Our Amazing World

Tsunami

by Joe Selzler

Before December 26th, 2004 I had barely heard the word "tsunami" much less understood what it meant. I didn’t even know that it was a Japanese word. But now, of course, everyone knows what the word means and what effect a tsunami can have. As of February 3rd 2005 the death toll has topped 300,000 with many more hundreds of thousands left homeless and whole towns and villages around the Indian Ocean basin devastated or completely destroyed. (Map) The tsunami was no respecter of persons as those who died came from every walk of life and religion. Besides being traumatised many are left asking the question: “Why?”

“Why did this happen?” “What did I do?” “Where was God?” “What did I do to anger him?” “Does he not care?” “Does he not see?” “Is he unable to stop such a disaster from happening?” Many people have put forward answers to these questions. Some have suggested spiritual or philosophical answers. Others have suggested rational, more down to earth answers. This soon after such a disaster most people who suffered are still trying to put the pieces of their lives back together and the rest of us are still busy offering all the help we can. Therefore there hasn’t been enough time for reflection on the reasons behind the tsunami. Sooner or later, however, when time has healed some of the pain, we will begin to ask why more earnestly. We will want to better understand the world in which we live and how we can live in it.

As a beginning, let’s start with a basic understanding of the physics of a tsunami. What follows is very basic. However, if you follow the links in the footnotes you can get a fuller explanation.

What is a Tsunami?

A tsunami (pronounced tsoo-nah-mee) is a wave train, or series of waves, generated in a body of water by an impulsive disturbance that vertically displaces the water column. Earthquakes, landslides, volcanic eruptions, explosions, and even the impact of cosmic bodies, such as meteorites, can generate tsunamis. Tsunamis can savagely attack coastlines, causing devastating property damage and loss of life.1

Tsunamis are unlike wind-generated waves, which many of us may have observed on a local lake or at a coastal beach, in that they are characterised as shallow-water waves, with long periods and wavelengths. The wind-generated wave might have a period of about 10 seconds and a wave length of 150 m. A tsunami, on the other hand, can have a wavelength in excess of 100 km and period on the order of one hour. As a result of their long wave lengths, tsunamis behave as shallow-water waves. Let’s see what this implies. In the Pacific Ocean, where the typical water depth is about 4000 m, a tsunami travels at about 200 m/s, or over 700 km/hr. Because the rate at which a wave loses its energy is inversely related to its wavelength, tsunamis not only propagate at high speeds, they can also travel great, transoceanic distances with limited energy losses.2

During a tectonic earthquake the sea floor abruptly deforms and vertically displaces the overlying water from its equilibrium position. Waves are formed as the displaced water mass, which acts under the influence of gravity, attempts to regain its equilibrium. When large areas of the sea floor elevate or subside, a tsunami can be created. 3

The above description is exactly what happened that December day in 2004. The tsunami was the direct result of the forces of nature. In the many questions that may be asked about the reasons for the tsunami one of the biggest might be “Why did God not intervene to stop the tsunami from happening?” One person has suggested that the very fact that no Supreme Being intervened is proof that one does not exist. They have suggested that the tsunami was the result of purely random, chaotic acts of nature based on natural laws. Is this true? Should we see the tsunami as a chance act of a cold and cruel world that operates completely by chance in line with the laws of nature? Is the absence of some supernatural intervention proof indeed that a supernatural power does not exist?

Friction

May I suggest that instead of the tsunami proving that a Supreme Being (God) does not exist it actually provides at least very strong evidence that one does exist. If we look at just one of the forces at work in the earthquake that produced the tsunami we can see why it is that a Supreme Being could not intervene to stop the tsunami. The force that I am referring to is friction. Most of us are probably aware that the cause of an earthquake is friction along a fault line in the earth’s crust, one famous fault line being the San Andreas Fault in Southern California. This fault in the earth’s crust is where the Pacific plate meets the North American plate. At this point the Pacific plate, with California attached, slides Northwest past the North American plate and as it does so friction builds up energy which is eventually released by an upward movement of one or another of the plates. This upward movement causes an earthquake that can destroy large cities in just a few minutes.

In order for a Supreme Being to prevent the earthquake that caused the tsunami of December 2004 he would have to eliminate the friction on the Indian Ocean fault that caused the earthquake, among other things. However, if the Supreme Being did remove the friction of just this one earthquake, would that be right and fair? How many other earthquakes would we want prevented by the removal of friction? Which ones would you or I choose to avoid by the removal of the friction that caused them? If we could choose, would not someone else have the right to question our choices? Perhaps the only fair way to prevent terrible disasters from earthquakes would be to remove all friction from the earth. But what would be the results of that?

Well, for one thing, if you own and drive a car you would not like the idea of a frictionless earth. That’s because you need the friction between the tires of your car and the road in order for you to safely steer your car on the highway. Without friction you would just careen off the road as soon as you tried to take a corner or navigate a bend in the road. Indeed, without friction you more than likely would not go anywhere at all, because your tires would probably just spin and not grab the pavement to propel you forward.

I believe the Supreme Being has created our world with certain laws that allow us to function and get things done. These laws are what give our world order instead of chaos. Without friction we would probably have cars in the ditch everywhere and no one getting anything done. Our world as we know it would “slide” to a chaotic halt. Earthquakes are not the result of random acts of a chaotic world but the result of created laws that allow our world to function properly. Contrary to what that one person has said, the tsunami does not prove there is no God -- but shows that He is one who has made an orderly world and will not do anything which would disrupt that order. Why? Because of God’s great love for us. He loves you and me so much that he made a world in which friction would make our lives liveable. Indeed, the same friction that ended so many lives and ruined so many more also made it possible for the rescue and relief efforts to save many more and make those lives liveable again. Is God a cold being who only cares about laws and rules of physics? By no means, for His heart felt deeply all of the pain and suffering of that day. If you or I have felt in our hearts a sense of compassion and sadness for those we have read about in the newspapers, or seen on TV, would not the one who made us with the capacity for such feelings have felt the pain even more? In understanding that, we can gain the comfort we need to face a world that is much bigger than us.

1. The Physics of Tsunamis http://www.geophys.washington.edu/tsunami/general/physics/physics.html
2. How do tsunamis differ from other water waves? http://www.geophys.washington.edu/tsunami/general/physics/characteristics.html
3. How do earthquakes generate tsunamis? http://www.geophys.washington.edu/tsunami/general/physics/earthquake.html
Additional Resources of Interest
"Separating Fact from Fiction" NBC miniseries 10.5 http://www.earthquakecountry.info/10.5/MajorMovieMisconceptions/ "Earthquake Myths" http://www.earthquakecountry.info/10.5/myths

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