Tsunamis are series of the ocean waves with very long wavelengths, hundreds of kilometers away, being brought about by various processes like sub marines, landslides, glacier calving, volcanic eruptions, meteorite impacts but greatly by earthquakes. It is formed in the ocean and big lakes.
Tsunami originated from the Japanese words tsu meaning harbor and nami meaning wave to make a harbor wave. Tsunamis have in the past and present brought catastrophic devastation to property and human death like in North East of Japan, on March 11, 2011. We shall dwell on the Shifts in the Tectonic plates as the reasoning behind the Tsunamis, but we have to understand the concept involved in the movement of the plate tectonics then how the earthquake will be generated to result into tsunami.
Plate Tectonics
These are movements of the lithospheric plates. Tectonics is movement and deformation of the crust, which integrate the ancient theory of continental drift. Plates are the lithospheric plates which are about 100 kilometers or more (Earth Quake Museum, 2011, p. 1). Plate tectonics mostly produces earthquake.
It should be noted that, the earth crust consist of plates sections that float on the molten rock of the mantle (Earth Quake Museum, 2011, p. 1). The movement of the plates is due to the conventional current. Conventional current is brought about by relationship between the densities of the fluid to its temperature. We can say that convectional current is the flow that transfers heat within a fluid by setting in motion by the heating and cooling of the fluid which changes in its density and continues as long as it heats.
The magma containing material at very high temperatures rises and spreads on the surfaces creating a new crust which spreads out forming a new plate, until it meets other plates (Earth Quake Museum, 2011, p. 1). After such a mechanism, then one of the plates will pushed down into the inferior of the earth and reabsorbed in the mantle; plates can also compress to push up the mountains when they collide or move sideways along the transform faults (Earth Quake Museum, 2011, p. 1).
The process of plates movements is a bit detailed as explained by the Geography site below:
One of the most famous examples of plates sliding past each other is the San Andreas Fault in California. Here the two plates, the Pacific plate and the North American plate both move in a roughly in the northwesterly direction, but one is moving faster than the other. The San Francisco area is prone to many small earthquakes every year as the two plates grind against each other. (Geography site, 2006, p. 1)
Plate Boundaries
The above diagram shows, Divergent Boundaries occur at Oceanic Ridges, where new Oceanic lithosphere is formed and moves away from the ridge in opposite directions (The Earth and Beyond, 2011, p. 1).
Shown above: convergent Boundaries occur where oceanic lithosphere is pushed back into the mantle, marked by oceanic trenches and subduction zones (The Earth and Beyond, 2011, p. 1).
Two types are possible
When two plates of oceanic lithosphere converge oceanic lithosphere is subducted beneath oceanic lithosphere; when ocean lithosphere runs into a plate with continental lithosphere, the oceanic lithosphere is subducted beneath the continental lithosphere (The Earth and Beyond, 2011, p. 1).
Transform Boundaries occur where two plates slide past one another horizontally; the San Andreas Fault, in California is a transform fault (The Earth and Beyond, 2011, p. 1).
Continental rifting may create a new divergent margin and evolve into an oceanic ridge, such as is occurring in East Africa and between the African Plate and the Arabian Plate (The Earth and Beyond, 2011, p. 1).
It has been shown that the plates play very significant role in making the earth crust unstable:
Continental lithosphere collide to join two plates together, such as has occurred recently where the Indian Plate has collided with the Eurasian Plate to form the Himalaya Mountains. Plate tectonics explains why earthquakes occur where they do, why volcanoes occur where they do, how mountain ranges form, as well as many other aspects of the Earth. It is such an important theory in understanding how the Earth works. (The Earth and Beyond, 2011, p. 1)
How Earthquake will generate tsunami
After fault has been created the earthquake will occur on it due to the massive violent movement as the two plates compress one another or override one another causing heavy pressure on the underlying rock. This causes vibrations or shockwaves to go through ground. As the solid rock plate moves up beneath the sea, there is a sudden movement within the crust or mantle and concentric shock waves moves out of that point (Geography site, 2006, p. 1).
The point of origin is referred as the focus, where in a radius of around 250 miles the effect is greatly felt, and the point directly above the surface is called the epicenter (Geography site, 2006).
A Tsunami is formed when the sea floor abruptly deforms and vertically displaces the overlying water (Geography site, 2006, p. 1). Earths crust deforms from at points below the ocean consequently disturbing the overlying mass of water. The process continues as thus:
The water above is displaced from its equilibrium position. The waves will be as result of the displacement of the water mass, which act under influence of gravity, to regain its equilibrium position. The potential energy that results from the uplifting or pushing of the water above mean level is then transferred to horizontal propagation of tsunami wave which possess the kinetic energy. (Tsunami, 2011, p. 1)
Tsunamis will results when a large sea floor elevate. Within several minute of earthquake, the initial, panel 1, is split into a tsunami that travels out of the deep ocean and another travelling to the nearby coast (Tsunami, 2011).
The tsunami will be greatly affected as it travels through the ocean where the rate at which the wave loses its energy is related to its wavelength. At deep waters the wave will travel at a very high velocity and as it approached the shoe or as the depth decreases the speed of the wave decreases; however the energy of the wave remains constant.
Conclusion
From the above study, tsunamis are produced or generated by the plate tectonic beside where the movement of the tectonics due to convectional current due to the heat coming from the earth center. This produces the movement of the plate where one plate moves toward the other and collide resulting in the faults being formed. This movement causes a ground shaking movement resulting into elastic waves travelling through the solid earth where one plate is emerged above the other and this causes an upward movement.
The upward movement causes the water above to be displaced, pushing a large volume of water upwards and the potential energy involved is transformed to horizontal kinetic energy which is massive causing formation of a wave of water which is the tsunami. For the last tsunamis they have occurred through this method.
A tsunami is one of the dangerous hazards, as it usually takes away the lives of many individuals. Additionally, tsunamis happen rather fast and often, and the researchers still lack knowledge in the prediction and announcements of the natural hazards in time. Despite the quick improvement of technology and political changes, tsunamis still have a tendency to be disturbing since not many people can react rapidly to the sudden alert of danger. Nonetheless, the primary goal of this paper is to evaluate and discuss the tsunami, which took place in 2011, in Tohoku. This devastating tsunami occurred after the strong earthquake with a magnitude of 9.0 (Poster of the great Tohoku earthquake 2012). In this instance, Figure 1 presents the devastating results of the tsunami. It could be seen in the picture that the heavy cars are floating in the water, and the water occupies the whole coastline of the east of Japan (Vehicles are washed away by tsunami 2011). Nonetheless, the image does not present over destructions, as the building was also dramatically damaged by the tsunami.
Figure 1. Vehicles are washed away by the tsunami (Vehicles are washed away by tsunami 2011).
Analysis
In this instance, the geological origin of the tsunami has to be discussed due to the fact that it plays a significant role in predicting the presence of a tsunami in the future. In turn, the types of tsunamis also have to be evaluated, as they have different levels of destructive power. All of these aspects will be also assessed in the context of Tohokus tsunami in 2011. In the end, the conclusions are drawn to determine the level of danger of this natural hazard to the existence of humankind. These aspects will help understand the nature of tsunamis and determine their impact on the existence of humankind.
Firstly, the geological origin of the tsunami has to be discussed to determine the potential reasons for tsunamis occurrence. One of the reasons is the volcanic eruption. A release of magma happens due to the high density of magma and other gasses under the Earths crust (Masters 2012). It remains evident that, in this case, significant volumes of debris crash into the ocean and cause the presence of strong waves in the ocean. In turn, the debris causes the water to move towards the shore with the high speed and make the tsunamis. Nonetheless, another primary cause of the tsunami is the earthquake. In this instance, the earthquake occurs due to the release of the pressure under the crust of the Earth, and the lithospheric plates slowly move (Levin & Nosov 2009). In this case, the epicenter of the earthquake is also the center of the tsunami since the waves start the slow movement. Speaking of the case of Tohoku in 2011, it remains evident that the primary reason is the earthquake, as its magnitude was 9.0. It could be said that this magnitude is enough to create a rapid and destructive tsunami, which is able to cause significant damage to Japan and other countries. In the end, all kinds of tsunamis are dangerous due to their rapid movement.
It remains apparent that different kinds of tsunamis have a tendency to be present. In this case, regional, local, and distant are the main types of tsunamis (Mercado-Irizarry & Liu 2006). The local tsunamis occur rather fast, and the population is not able to react fast to the danger. Additionally, the waves are rather fast, and the government is not able to announce the existence of danger to the population. In turn, regional and distant tsunamis are less dangerous, as their travel is longer (Mercado-Irizarry & Liu 2006). It could be said that, in this case, the population of the country can be evacuated, as more time is available. Nonetheless, despite having longer travel distance, these types of tsunamis are rather dangerous and destructive due to the high power. Speaking of the case of Tohoku, the tsunami had a short traveling distance, as the earthquake occurred near the coast of Japan. In this instance, the destructive power was high, as the population was not able to react fast to the accident.
Conclusion
In the end, tsunamis are one of the most dangerous hazards since they are still hard to predict. They tend to appear fast, and it is hardly possible to get the population evacuated on time. Its destructive power was displayed with the assistance of the tsunami in Tohoku. Nonetheless, the two primary reasons for their appearance are volcanic eruptions and earthquakes. This knowledge helps reduce the number of victims from natural hazards. However, it is still one of the most powerful hazards and causes high danger to the existence of humankind. Additionally, some of the animal species might disappear from the surface of the planet due to the occurrence of the tsunamis. It could be said that more research regarding the tsunamis has to be conducted to lessen the dangerous effects of these hazards and minimize the number of victims.
Reference List
Levin, B & Nosov, M 2009, Physics of tsunamis, Springer Science + Business Media B.V., New York.
Masters, N 2012, Volcanic eruptions, Cherry Lake Publishing, North Mankato.
Mercado-Irizarry, A & Liu, P 2006, Caribbean tsunami hazard, World Scientific Publishing Co. Pte. Ltd., Singapore.
Poster of the great Tohoku earthquake (northeast Honshu, Japan) of March 11, 2011 magnitude 9.0 2012, Web.
Vehicles are washed away by tsunami 2011, image, Web.
A tsunami is one of the critically dangerous natural disasters that might result in crucial devastations. On December 26, 2004, the areas of Indonesia, Malaysia, Myanmar, Sri Lanka, India, and the Maldives were hit by a tsunami produced by the earthquake 155 kilometers from Sumatra (Schmidt, 2005). The 30 feet high waves killed more than 150,000 people and preconditioned traumas among millions of other victims, making it one of the worst natural disasters of this sort in history (Schmidt, 2005). At the same time, it demonstrated the inability of existing warning systems to respond fast and effectively and protect people by evacuating them and providing an appropriate shelter. The problem was that the Indian Ocean area lacked sensor technologies to detect earthquakes that might signalize the appearance of a tsunami (Schmidt, 2005). The absence of needed tools critically deteriorated the effectiveness of the whole warning system.
Today, multiple attempts are performed to avoid the repetition of the scenario and improve the current methods of managing tsunamis. There is a specific Ocean Tsunami Warning and Mitigation System (IOTWMS), which is considered a successful end-to-end warning system that helps to detect the first signs of the earthquake in the ocean and warn the appropriate authorities responsible for organizing the population and its transporting to safe areas. (Hettiarachchi, 2018). Adopting systems results in increased preparedness and awareness levels, while the severity of outcomes decreases (Hettiarachchi, 2018). In such a way, it is possible to conclude that the poor functioning of awareness systems in the past preconditioned the reconsideration of the approach to monitoring tsunamis and warning people about them. Today, frameworks such as IOTWMS can be viewed as sufficient and adequate enough to save lives.
References
Hettiarachchi, S. (2018). Establishing the Indian Ocean Tsunami Warning and Mitigation System for human and environmental security. Procedia Engineering, 212, 1319-1346. doi:10.1016/j.proeng.2018.01.173
Schmidt, C. (2005). Natural disasters: Building a tsunami warning system. Environmental Health Perspectives, 113(2), A90. doi:10.1289/ehp.113-a90
Tsunami can be defined as a sequence of ocean waves of bizarrely enormous length that are engendered by incessant uproars of the earths outer layer. This sticking force causes mass destruction of property and human beings. There is also a widespread epicenter under or near the ocean, and with a vertical displacement of the ocean floor; these strong waves have numerous effects to Human beings (Danninger and Kang 75).
Tsunami Dangers
Loss of Life
Many lives of people along Japans coastal regions have been lost because population along coastal regions has been growing tremendously. This historically can be traced in parts of Japans coastal region which is closely populated according to a research, it is estimated that over 1,000 people lost their lives after the 1960 tsunami in Japan.
The force of tsunami waves may kill people instantly, or they may drown people when water rushes to land, the electrical installation also contributed to this loss since there was a possibility of people being electrocuted if wires are exposed. Many people were affected psychologically in most of coastal regions, due to this loss. 1,000 houses were destroyed in September 1498, resulting to around 500 deaths following a tsunami that hit the Kii peninsula.
In September 1596, there was another destructive tsunami in Kyushu (OECD 56). These findings show severe effects of tsunamis to human beings who have been affected. Most of coastal regions vulnerable women, men, and their children lost their lives while carrying on with their daily chores.
Destruction and Damage
Many peoples property was lost since many businesses are set along the coastal lines during this devastating time. People lost their daily income due to the destruction. Coastal regions took long to stabilize because of this effect. Tsunami effects were reported in the media across the world.
However, these effects continued for many years after the natural disaster struck Japan. Many people affected, will never forget this terrifying experience of being caught in a tsunami they live to tell shocking of their life moments. Tsunami tide waves on the sore can destroy anything on the path these include. Boat buildings, hotels, cars trees telephone lines (Danninger and Kang 90).
New Diseases Emerged
The stagnant water displaced by tsunami waves in flooded areas also caused illnesses such as malaria from stagnated water and contamination. This caused more deaths and sickness in the affected areas. The tampering with infrastructure like sewerage and freshwater supplies worsened the situation. Lack of fresh water led to the outbreak of diseases like cholera and other related diseases due to this situation.
Victims Suffer Psychology Problems
This could continue for a while or often their entire lifetime According to the study done by WHO on survival of tsunami victims recorded stress, disorders to children, anxious among other effects that were noticed in the area. Loss of homes also resulted to depression.
High Cost of Fighting Tsunami
The total cost of tsunami could be billions of dollars since the damage of income-generating business, and the cost used to curb the situation on the ground was quite high. Japans government issued newer bounds for rebuilding and reconstruction. The country spent most of the finances on the victims.
The better part was that Japan has a substantial income. This made it easier for it to rekindle finances lost, since it has excellent infrastructure and quality health conditions on top of a huge economy. The greatest loss was demographic challenges and existing fiscal burden.
Export and Import Alteration
Since Japan is an industrialist state, it was affected in terms of exports and imports. Many of the manufactured products in Japan could still stay in ports since transporting them during tsunami was risky. Therefore, manufactured products like Honda Toyota, Sony added up to the financial burden consequently affecting the economy (OECD 43).
Closing down Japanese prime oil refineries due to the calamity decreased demand for oil and lowered the cost of crude oil prices. In addition, Japan is an industrialized country; shortage of electricity jeopardized the operations in this sector. This was attributed to slowdown due to the shortage of electricity generating capacity.
The Risk of Nuclear Reactors When Tsunami Hit Japan
Nuclear reactors in Japans tsunami and earthquakes have hampered efforts to get it restored. Some nuclear reactors lost their cooling ability during the tsunami prompting a rush against time to fix the problem. These media reports showed that Tsunami had a role to play in these reactors.
The Japanese Governments Treatment with the Tsunami
Before the Tsunami
Japanese governments ability to deal with crisis is beyond doubt. The fact that Japan is a developed country, it was in a position to respond to Tsunami swiftly. Despite its impact on the economy, Japan government had set its military base in order to respond to this situation (Dick and Nanto 27). This unique military base is capable of dealing with any situation of which they had set right materials and equipment and manpower to curb Tsunami.
This prompted this military base to keep on practicing and equipping itself from any calamity this readiness by the government was able to respond to the crisis swiftly and saved thousands of people. Special techniques and right equipment used by the government placed the government in a particularly strategic place. This acquainted the soldiers with confidence and also the residents.
A governments unique unit was of significant help to residents since it taught victims on how to respond to such calamities. Japans metrological department warned people of Tsunami and asked people to be cautious of it, by possibly vacating the area. The department used satellite and kept on monitoring the ground and alerted people on the television of its whereabouts.
However, this information came about late and people could not act swiftly to the onset of the Tsunami since it was quite fast. This left many people being confused on the way. Signs, alarms, and media warnings were a little bit late since the population was high along this region (Danninger and Kang 143). Unfortunately, many did not make it out of danger.
After the Tsunami Happened
Japan has tried to prevent Tsunami effects by building concrete breakwaters and floodgates to protect coastal areas around the country. This will prevent strong currents that come with force. However, it has warned that it cannot prevent Tsunami. Government has also set personnel to encourage the victims and depressed people to cope with the situation this has given the victims motivation to continue to survive (Dick and Nanto 46).
They have also set laws related to this destruction. These will be able to budget for the calamity when it occurs so as to avoid it hurting the economy. These guidelines have seen Japanese people build confidence in investing in coastal regions which were considered risky by many local and foreign investors.
This development has seen the Japanese recover from previous losses that arose from the Tsunami. Development of technology has also boosted swift measures on ocean areas. This has been done by setting new devices and machines which will help Japan to cope with Tsunami in future (OECD 32).
Conclusion
In conclusion, Tsunami can be defined as a sequence of ocean waves of bizarrely enormous length that are engendered by incessant uproars of the earths outer layer. This sticking force causes mass destruction of property and human beings. In Japan, Many people affected will never forget this terrifying experience of being caught in a tsunami they live to tell shocking of their lives moments.
In an effort to prepare for such a disaster, Japan has tried to prevent Tsunami effects by building concrete breakwaters and floodgates to protect coastal areas around the country. This will prevent strong currents that come with force.
Works Cited
Danninger, Stephan and Kenneth Kang. Finance & Development. Washington: International Monetary Fund, 2011. Print.
Dick K. Nanto. Japan|s 2011 Earthquake and Tsunami: Economic Effects and Implications for the United States. New York: DIANE Publishing, 2011. Print.
The stay of mankind on planet earth has often witnessed moments of helplessness when natural disasters have stuck; thus, destroying many lives and disorienting mankind in the process. From our earliest ancestors to the modern man, we have not been safe from the anger of natural disasters.
Ranging from volcanoes, hurricanes, tornadoes, and the destructive tsunamis, we are susceptible to an array of natural disasters that is always waiting to strike. Such was the case when a tsunami hit the coastline of Sri Lanka on 26th December, 2004.
Without warning, thousands of people were killed by the 2004 tsunami. Such is the common story that is often told when catastrophic disasters like a tsunami strikes. Although we have evolved in science and thus learned many secrets of our world, we have not been able to subdue natural disasters. Since all life is precious, it is our responsibility to use the resources we have, and adopt a behaviour that can help us preserve even a few lives during catastrophic events.
Generally, a tsunami can be defined as a series of wave disturbances which usually originate from a vertical displacement of a water column (Abek 1561). The word tsunami has an origin in the Japanese language. Here, tsunami can be directly translated as a series of waves that often form at bays (Hassain 51).
Usually, anything with a potential of displacing, or moving a large volume of water can cause a tsunami (Vitarana 84). The most common causes of tsunamis include earthquakes, moving heavenly bodies such as meteorites and asteroids, volcanoes, and landslides (Vitarana 84).
Earthquakes
Most tsunamis originate from earthquakes. Once an earthquake occurs on a sea bed, a large mass of water is displaced upwards. Due to the force of gravity, the displaced volume of water will move downwards to regain its original position (Vitarana 84).
A repetitive cycle where a water column moves up and down is created; hence forming a wave. Usually, a displacement of a water column will occur when part of a sea bed is displaced (UNEP 12). A fault line in the earths crust can especially create a boundary where a vertical displacement of the sea bed can easily occur (Liu 106).
Earthquakes that occur on subduction trenches are the main causes of most tsunamis (Liu 106). The tsunami waves that originate from an earthquake source can then move away from the place where they originate thousands of miles (Moore 143). Knowing the magnitude of an earthquake can especially be useful in determining the scale of tsunamis that have travelled thousands of miles from their source (Hassain 51).
Landslides
Tsunamis can also originate from landslides. Landslides can occur at the seabed, or at the coast (Vitarana 84). Possible causes of such landslides include the earthquakes, the erosion of sea slopes, and volcanoes (Hanson 67).
The erosion of coastal slopes can occur as a result of rain action, from sea waves, and storms (Hanson 67). Due to a displacement of sea water as a result of displaced debris from landslides, a series of waves that has a potential of causing a tsunami is formed (Van 24).
Volcanoes
When a volcano occurs above the surface of the sea, but in proximity to the seas surface, a large quantity of rock debris is thrown into the sea. When such debris falls into the sea, it displaces water; hence, creating waves that can cause a tsunami.
However, volcanic eruptions that occur under a sea are more hazardous in forming tsunamis (Hassain 51). Tsunamis can originate from a displacement of water that is caused from a rising slope of a volcano (Van 24).
Besides, gases that are usually released from an erupting volcano can also cause a large water displacement; hence, forming a tsunami in themselves (Hanson 67). Moreover, a volcano can also trigger an earthquake, which can then trigger a tsunami (Damen 106).
Meteorites, Comets and Asteroids
Our earth is constantly in danger of colliding with heavenly bodies like comets, asteroids and meteorites (Hanson 67). While one might think that great damage from such collisions will occur if such bodies hit the earths surface in an area that is densely populated (such as a town), a greater catastrophic damage will happen if such bodies strike at sea (Abek 1561).
For example, scientists estimate that if an asteroid that is about six kilometres in size was to fall in the middle of the Atlantic Ocean, a third of the US population would be killed (Damen 106). The gigantic speed and size of a typical asteroid can create huge waves (tsunamis) that can cause a devastating damage to our population (Liu 106).
Although the possibility of us experiencing such a collision (from a heavenly body such as a comet) is almost zero, there is always a possibility, however remote, of such a catastrophe (Abek 1561).
Activities of Man
Any human activity that can result in a displacement of a large volume of sea water can lead to the build-up of a tsunami wave. The carrying out of nuclear tests in deep sea can especially release large amounts of energy which can then displace large volumes of sea water; hence, leading to the development of a tsunami wave.
Characteristics of a Tsunami
As we had seen earlier, a tsunami originates from a displacement of a large volume of water (Van 24). Such a displacement creates a wave that moves up and down. A tsunami is therefore a wave that is very similar to the kind of wave ripples that we usually observe when we throw a stone in a tank of water (Damen 106).
Very often, a tsunami will travel as a series of multiple waves; hence, it is usually called a train of waves (Damen 106). Once it forms, a tsunami can travel thousands of miles in the sea before reaching a coastal area (Liu 106).
For example, a tsunami with an origin in the Atlantic can travel at an incredible speed of over 1000 km/hr to reach the Japanese coastline within 24 hours. Usually, tsunamis travel at very high speeds in deep sea waters (Hassain 51).
However, on reaching shallow waters, the speeds of tsunamis usually reduce gradually (Van 24). Such behaviour results from an energy flux that remains constant during a wave travel (Hanson 67). Since the energy flux of a tsunami is proportional to the speed and amplitude of a tsunami wave, tsunamis at deep waters will travel at high speeds and low amplitudes.
Unlike their counterparts in shallow waters, such tsunamis will usually consist of waves that are small in amplitude and long (in horizontal size) (Abek 1561). Indeed, it is sometimes difficult to physically observe a tsunami wave that is travelling in the deep sea (Moore 115).
However, as a tsunami moves into shallow waters towards a coastal area, its speed decreases while its amplitude increases. Travelling at a speed that is proportional to the square root of gravity constant multiplied by depth, a tsunami that is travelling in water that has a depth of five kilometres can move at a speed of over 800 km/hr.
On hitting a coastline, such a tsunami can travel at amplitude that is within ten to fifty meters. Such tsunamis can be observed as a series of water waves forming a series of rises that alternate with falls at the coastline. Usually, tsunamis can occur for several hours.
Like any other wave, tsunami waves can add to one another to form waves with higher amplitudes, or subtract from one another to form waves of lower (or zero) amplitudes (Moore 116).
The 2004 Tsunami in Sri Lanka
The date of 26th December, 2004, will be remembered for a long time by many people in Sri Lanka. During this particular date, a tsunami of a large magnitude and scale hit the coastline of Sri Lanka (Liu 117). The 2004 tsunami in Sri Lanka was caused by an earthquake of a high magnitude that occurred in the western coast of Sumatra (Moore 138).
The focal depth of this particular earthquake was about thirty kilometres (Liu 117). Described as the worst earthquake to occur in the history of our planet in the past five decades, the earthquake that caused Sri Lankas tsunami measured over 9.0 on the Richter scale (Liu 106).
The above earthquake originated from an interaction of Australian, Sunda, and Burmerse tectonic plates. Here, as much as 30 meters of the sea bed covering a distance of over one thousand kilometres was displaced (Abek 1561).
Thus, the displacement that was caused by the described tsunami resulted in a vertical displacement of a very large volume of water; hence, creating a tsunami (Moore 129). Moreover, the 9.0 earthquake caused a series of about fifteen other earthquakes in the affected region.
As a result of a water displacement (caused by the resulting upward movement of the sea floor) that was caused by the 9.0 earthquake, a series of three tsunami waves was formed (Liu 106). Time duration between these tsunami waves averaged about twenty minutes.
Effects of the 2004 Sri Lankas Tsunami
When a tsunami reaches a coastline, it travels with high amplitude (from ten meters to even fifty meters). Thus, water overflows from the coastline towards the inland. Such a moving volume of water travels at a high speed, and with enormous energy that can cause huge destructions.
The 2004 tsunami, which hit the Sri Lankan coastline, affected more than two thirds of the Sri Lankan coastline. More than 20% of the Sri Lankan population was thus affected by the 2004 tsunami. Here, the moving tsunami wave drowned and killed thousands of people.
There were especially many deaths since the country was not expecting a tsunami, and was not therefore prepared for an emergency evacuation. It is reported that due to ignorance, thousands of Sri Lankas went to learn of what had happened when the first of the three series of tsunami waves hit their coastline (Liu 119).
Usually, due to interactions with a coastline (often leading to a loss of energy), the first wave of a tsunami is often less devastating than those that follow after it. Thousands of people here were thus caught unaware and killed by the second wave of the 2004 tsunami.
The total number of people who were killed in Sri Lanka by the 2004 tsunami has been estimated to be around 31,000 in total (Liu 119). A larger proportion of those killed by the 2004 Tsunami consisted of women and children.
It is estimated that over 10,000 of those killed here during the tsunami disaster consisted of children (Liu 119). Apart from deaths, about seventeen thousand people were injured by the tsunami tragedy while more than five thousand were reported as missing (Liu 119).
Moreover, the overflowing waters of the 2004 tsunami resulted in a massive destruction of property along the Sri Lankan coastline. As a result of the 2004 tsunami tragedy, more than eighty thousand homes were destroyed; hence, displacing about a million individuals as a result.
So as to cater for the needs of the people who were displaced by the 2004 tsunami in Sri Lanka, about 800 camps for the displaced were formed. Many of the people in these resettlement camps had lost their property and livelihoods as a result of the tsunami tragedy. Many others had to undergo psychological trauma due to the negative ways in which the tsunami had affected their ordinary living.
Apart from houses, many infrastructural facilities were destroyed by the 2004 tsunami; thus affecting transport, communication and also posing a reconstruction challenge. A lot of debris could be seen around all the areas that had been affected by the tsunami.
Besides, the 2004 tsunami affected the ground fresh water table through salinization of fresh water sources. It will take a lot of efforts and time to clean some of these water tables that were affected.
Since the Indian Ocean bed has been proven to contain lesser amounts of titanium as compared to the Pacific Ocean, more studies will be required before we can determine if large amounts of titanium was deposited inland during the 2004 tsunami.
Economic Impacts
The 2004 tsunami affected the economy of Sri Lanka in several negative ways. Many people lost their sources of livelihoods as a result of the 2004 tsunami. Some of these people who had lost their livelihoods had lost their businesses and houses, which had been destroyed by the destructive tsunami waves (Dawson 224).
Moreover, since a large community of the Sri Lankan population depends on fishing, many fishermen became poor as a result of losing their boats to the destructive tsunami waves that had hit their coastline (Dawson 224). A United Nations report on the 2004 tsunami catastrophe estimated that about two hundred thousand people in Sri Lanka were in danger of becoming poorer following the 2004 tsunami tragedy (Dawson 224).
Because a large part of hotels, beaches, among other tourist facilities were destroyed by the tsunami tragedy, the tourism economy of Sri Lanka was affected negatively. With no places were tourists could visit and relax, the number of tourists arrivals in Sri Lanka decreased significantly.
As a result, many people who were directly employed by the tourism sector lost their jobs. Moreover, due to a decrease in tourist arrivals, Sri Lanka was thus losing an important source of foreign exchange for developing her economy.
With a destruction of her infrastructure as a result of the tsunami tragedy, billions of dollars were needed for restructuring. With limited resources, it will be difficult to meet the cost of restructuring affected infrastructure. Meanwhile, as a result of infrastructural destruction, many businesses were affected negatively (Dawson 224).
Many of these businesses depend on telecommunication, electrical power, and transport to carry on with their day to day activities. Most of these businesses are small businesses that contributed positively to the Sri Lankan economy (through employment of people and paying of taxes).
Since most of these businesses have suffered from a displacement of people (hence a loss of market and human resource), and also from a physical damage of their properties and facilities, they have found themselves in a very repelling environment to operate in; thus, limiting their capacity and output to the Sri Lankan economy.
Measures that can be taken to Avoid Future Tsunami Disasters
No matter how much we prepare, we can never be ready for natural disasters. However, a possible measure of precautions and preparedness can help us to avoid, or minimize the destructive effects of natural disasters.
Although there is uncertainty on the effectiveness of using technology to mitigate the effects of natural disasters such as tsunamis, we should always work in the direction of utilizing such technologies if we can save a few lives as a result.
Together with several countries, the United States has developed and placed sensors at specific areas on the seabed of the Pacific Ocean. These pressure sensors have been designed to detect possible tsunami waves (UNEP 18).
Since tsunamis consist of waves that have rising and falling amplitudes, the resulting difference in the depth of water can cause pressure alterations at sea beds. These pressure alterations can thus be detected by pressure sensors at the seabed (Meihde 56).
However, since such a process of measurement is highly complex, it is very difficult for sensors at the sea bed to have accuracies that can detect tsunami waves. Still, the progress that has been made in using sensors to analyse data for a possible tsunami waves is positive (UNEP 12).
Moreover, since tsunamis interact with the coastline in a way that is difficult to predict, it is equally difficult to predict their behaviour. Sometimes, tsunami waves can add together or cancel one another; hence, making it difficult to determine their eventual behaviour (Meihde 56).
Several researchers remain uncertain if the tsunami warning technology in the Pacific Ocean can be replanted in the Indian Ocean. Still, Sri Lanka has been part of an ongoing program that has been working with several other countries to develop a system that can monitor for possible tsunamis before they occur (Liu 106).
Under the tsunami warning system, The Sri Lankan meteorological department will work together with Japanese technologies and the Pacific Tsunami Warning System (PTWC) to possibly help in the detection of future tsunamis (Yadav 107).
Although we do not have a reliable system of detecting tsunamis, the above development is progressive in developing reliable systems that can be useful in detecting and monitoring tsunamis before they hit a coastline (Andrew 23). However, since the Indian Ocean bed is different in structure and complexity to the Pacific Ocean bed, there is a need for scientists to develop a warning system that is unique to the Indian Ocean (Patra 362).
Currently, there has been a debate on whether to allow building of houses a few meters from the coastline (UNEP 21). Here, it will be useful to develop buildings that are protective and safe from tsunamis. Importantly, there is also a need to conserve the Sri Lankan coastline (Meihde 56).
A huge part of the coastline should be planted with mangrove forests (Patra 362). A thick cover of mangrove forests is useful in cutting and breaking tsunami waves before they move further inland (Yadav 107). Conservation of the Sri Lankan coastline will thus be useful in at least reducing possible damages that may occur from future tsunamis (Andrew 22).
Importantly, the political leadership in Sri Lanka has become more aware of damages that can result from natural disasters like tsunami attacks.
With such awareness, the political leadership in Sri Lanka can prepare for emergencies and move with speed to mitigate damages that can arise from similar disasters in the future (Patra 362). Here, it will be useful to develop a quick response system that can help in quick evacuations and treatments during times of natural disasters (Yadav 107).
An important area that needs to be utilised for the purposes of mitigating the effects of future natural disasters is the use of technology. Here, technology can especially be used to help in assessing the damage that could have occurred following the occurrence of a natural disaster (Patra 362).
Importantly, technology can be employed to communicate with the people who are in danger of being hit by a natural disaster (Andrew 22). It is fruitful to relay information to a target populace with instructions on where they can move to stay safe, what they can do, and how they can ask for help during such times (Meihde 56).
As we had seen earlier, a large number of people who died during the 2004 tsunami attack died from the second wave (Yadav 107). Having heard of what had happened, many people moved in ignorance to witness the effects of the first wave before the more deadly second wave hit (Yadav 107).
With the right communication, these people could have been told to stay away from the beach; hence, cutting on the number of fatalities that occurred (Patra 362). As it has been proven time and again, an effective system of coordination and communication is essential in saving lives during times of natural disasters (Andrew 23).
Conclusion
Natural disasters will always remain a part of us during our stay on planet earth. So as to minimize the loss of lives during natural disasters, it is useful for man to utilize all resources at his disposal to preserve lives during the occurrence of natural disasters.
Such a direction would involve understanding the science of natural disasters like tsunamis, and thus develop measures that can help in warning, planning and rescue programs when natural disasters strike. The 2004 tsunami has especially provided us with important lessons on the direction that we can adopt to prevent massive deaths during such disasters.
Adopting programs that are helpful in preparing for such disasters can be fruitful in saving many lives.
Such a direction would involve developing an efficient system of communication, designing and implementing a standby resource of manpower and machinery for emergencies, using technological systems to warn for possible oncoming disasters, and importantly, developing a system of peaceful coexistence with our natural environment (such as the planting of mangrove forests along coastlines to help in subduing tsunamis).
Works Cited
Abek, Kennedy, Physical Size of Tsunamigenic Earthquakes from Tsunami Data. Journal of Geography Research, volume 84.1 (2006): 1561-1568. Print
UNEP, Early Warning Systems, New York: UNEP Press, 2011. Print Van, Frank, the Science of Tsunamis, New York: International Institute For geo-information Science Press, 2006 Print
Vitarana, Tissa, Sri Lanka after the Indian Ocean Tsunami New York: International Institute for geo-information Science Press, 2006 Print
Yadav, Agarwal, Soil, Water Conservation. Mumbai: Oxford, 2007. Print
Tsunamis are series of the ocean waves with very long wavelengths, hundreds of kilometers away, being brought about by various processes like sub marines, landslides, glacier calving, volcanic eruptions, meteorite impacts but greatly by earthquakes. It is formed in the ocean and big lakes.
Tsunami originated from the Japanese words ‘tsu’ meaning ‘harbor’ and ‘nami’ meaning ‘wave’ to make a ‘harbor wave’. Tsunamis have in the past and present brought catastrophic devastation to property and human death like in North East of Japan, on March 11, 2011. We shall dwell on the Shifts in the Tectonic plates as the reasoning behind the Tsunamis, but we have to understand the concept involved in the movement of the plate tectonics then how the earthquake will be generated to result into tsunami.
Plate Tectonics
These are movements of the lithospheric plates. Tectonics is movement and deformation of the crust, which integrate the ancient theory of continental drift. Plates are the “lithospheric plates which are about 100 kilometers or more” (Earth Quake Museum, 2011, p. 1). Plate tectonics mostly produces earthquake.
It should be noted that, “the earth crust consist of plates sections that float on the molten rock of the mantle” (Earth Quake Museum, 2011, p. 1). The movement of the plates is due to the conventional current. Conventional current is brought about by relationship between the densities of the fluid to its temperature. We can say that convectional current is the flow that transfers heat within a fluid by setting in motion by the heating and cooling of the fluid which changes in its density and continues as long as it heats.
The magma containing material at very high temperatures “rises and spreads on the surfaces creating a new crust which spreads out forming a new plate, until it meets other plates” (Earth Quake Museum, 2011, p. 1). After such a mechanism, “then one of the plates will pushed down into the inferior of the earth and reabsorbed in the mantle; plates can also compress to push up the mountains when they collide or move sideways along the transform faults” (Earth Quake Museum, 2011, p. 1).
The process of plates’ movements is a bit detailed as explained by the Geography site below:
One of the most famous examples of plates sliding past each other is the San Andreas Fault in California. Here the two plates, the Pacific plate and the North American plate both move in a roughly in the northwesterly direction, but one is moving faster than the other. The San Francisco area is prone to many small earthquakes every year as the two plates grind against each other. (Geography site, 2006, p. 1)
Plate Boundaries
The above diagram shows, “Divergent Boundaries occur at Oceanic Ridges, where new Oceanic lithosphere is formed and moves away from the ridge in opposite directions” (The Earth and Beyond, 2011, p. 1).
Shown above: “convergent Boundaries occur where oceanic lithosphere is pushed back into the mantle, marked by oceanic trenches and subduction zones” (The Earth and Beyond, 2011, p. 1).
Two types are possible –
“When two plates of oceanic lithosphere converge oceanic lithosphere is subducted beneath oceanic lithosphere; when ocean lithosphere runs into a plate with continental lithosphere, the oceanic lithosphere is subducted beneath the continental lithosphere” (The Earth and Beyond, 2011, p. 1).
“Transform Boundaries occur where two plates slide past one another horizontally; the San Andreas Fault, in California is a transform fault” (The Earth and Beyond, 2011, p. 1).
“Continental rifting may create a new divergent margin and evolve into an oceanic ridge, such as is occurring in East Africa and between the African Plate and the Arabian Plate” (The Earth and Beyond, 2011, p. 1).
It has been shown that the plates play very significant role in making the earth crust unstable:
Continental lithosphere collide to join two plates together, such as has occurred recently where the Indian Plate has collided with the Eurasian Plate to form the Himalaya Mountains. Plate tectonics explains why earthquakes occur where they do, why volcanoes occur where they do, how mountain ranges form, as well as many other aspects of the Earth. It is such an important theory in understanding how the Earth works. (The Earth and Beyond, 2011, p. 1)
How Earthquake will generate tsunami
After fault has been created the earthquake will occur on it due to the massive violent movement as the two plates compress one another or override one another causing heavy pressure on the underlying rock. This causes vibrations or shockwaves to go through ground. As the solid rock plate moves up beneath the sea, “there is a sudden movement within the crust or mantle and concentric shock waves moves out of that point” (Geography site, 2006, p. 1).
The point of origin is referred as the focus, where in a radius of around 250 miles the effect is greatly felt, and the point directly above the surface is called the epicenter (Geography site, 2006).
A Tsunami is formed when “the sea floor abruptly deforms and vertically displaces the overlying water” (Geography site, 2006, p. 1). Earth’s crust deforms from at points below the ocean consequently disturbing the overlying mass of water. The process continues as thus:
The water above is displaced from its equilibrium position. The waves will be as result of the displacement of the water mass, which act under influence of gravity, to regain its equilibrium position. The potential energy that results from the uplifting or pushing of the water above mean level is then transferred to horizontal propagation of tsunami wave which possess the kinetic energy. (Tsunami, 2011, p. 1)
Tsunamis will results when a large sea floor elevate. Within several minute of earthquake, the initial, panel 1, is split into a tsunami that travels out of the deep ocean and another travelling to the nearby coast (Tsunami, 2011).
The tsunami will be greatly affected as it travels through the ocean where the rate at which the wave loses its energy is related to its wavelength. At deep waters the wave will travel at a very high velocity and as it approached the shoe or as the depth decreases the speed of the wave decreases; however the energy of the wave remains constant.
Conclusion
From the above study, tsunamis are produced or generated by the plate tectonic beside where the movement of the tectonics due to convectional current due to the heat coming from the earth center. This produces the movement of the plate where one plate moves toward the other and collide resulting in the faults being formed. This movement causes a ground shaking movement resulting into elastic waves travelling through the solid earth where one plate is emerged above the other and this causes an upward movement.
The upward movement causes the water above to be displaced, pushing a large volume of water upwards and the potential energy involved is transformed to horizontal kinetic energy which is massive causing formation of a wave of water which is the tsunami. For the last tsunamis they have occurred through this method.
The Tsunami disaster that occurred towards the end of 2004 resulted in a huge burden on the community both in physical terms and psychological trauma. A big number of the population lost their lives and property worth millions of dollars was destroyed. In addition, members of the families that were diseased were left with psychological trauma that affected them after the event.
The community and government were left with a major challenge of how to cope with the physical and psychological stress that was quite evident. Many individuals were not only in need of material assistance, but also psychosocial care to help them cope with the psychological trauma they went through.
Most of the individuals suffered from anxiety disorders, depressive disorders, as well as post traumatic stress disorders (PTSD). PTSD is a disorder people go through after experiencing a dangerous event. This is a severe disorder and can last for a few days to months. The severity depends on the intensity of the dangerous event as well as the surrounding circumstances.
PTSD is also experienced by solders after taking part in wars and the symptoms can affect them for the rest of their lives. Most of the Tsunami victims experienced PTSD which affected their family life, social life as well as their work. Most of them had to shelter in camps since most of their houses were destroyed. It is in these camps that they received both physical and psychological help.
This paper will look at what is meant by PTSD and the symptoms of this disorder. It also gives an overview of the Tsunami disaster including the physical and psychological effects of the dangerous events. It will go further to highlight the recovery response that was initiated to help the Tsunami PTSD patients and conclude by looking at the psychoanalysis theory developed by Sigmund Freud.
Post Traumatic Stress Disorder
Post-traumatic stress disorder is an anxiety people go through after experiencing a dangerous event. When people are in danger, they are normally engraved with fear and uncertainties of the outcomes of such an event. This is a health response and it is meant to help the body as it defends itself against danger. However, a person who experiences post traumatic stress (PTSD) may have a damaged reaction. Individuals under PTSD most of the time feel strained and terrified even when out of danger.
They fear for their lives and most of them suffer from sleepless nights because they are even afraid of sleeping (Myers, 2010). The occurrence of the dangerous event keeps recurring on people’s mind causing anxiety and depression. If a person is not treated early, he may suffer from PTSD for the rest of his life and may even lead to untimely death.
Any person can be a victim of PTSD; it affects children, the youths, and even old people. It normally affects people who have gone through a dangerous situation or witnessed a dangerous event. Events that can cause PTSD include war, sexual assault, motor accidents, and natural disasters such as earthquakes, fires, the tsunami, and many others.
However, it is worth noting that not every person that experiences PTSD has actually experienced a dangerous event. There are people who get PTSD after receiving bad news, for instances, news about the death of a loved one or a friend.
Symptoms of PTSD
The symptoms of PTSD vary with the kind of danger. These symptoms can be classified into three classes as follows:
Re-experiencing symptoms- this includes flashbacks about the dangerous event, bad dreams, or terrifying thoughts. These symptoms may interfere with a person’s daily routine because of lack of concentration. Some people even day dream and may bust out crying, shouting or running for help. Symptoms may be re-experienced where object or even prevailing situations may elicit the signs (Myers, 2010). These symptoms require professional help to deal with because a person experiencing them live with self denial and does not accept what he is going through. They can last for 4-6 weeks or even months after the event but this depends on a person’s willingness to accept assistance and the desire to change.
Avoidance symptoms- a person experiencing PTSD tries to keep away from any object or situation that will be a constant reminder of the event. Others even withdraw themselves from the society and their participation in social activities diminishes. At times, they may be overcome by feel emotions and start carrying without a reason. Other people experience depression, worry or remorse, while others may tend to shun away from activities that they found enjoyable before the event took place. The first step in helping a person with these symptoms is to remove all objects that may act as a constant reminder of the event and also to change his environment so that he is able to see life from another angle.
Hyper arousal symptoms- they include feeling tense, insomnia, or being angered easily. These symptoms are hardly triggered by objects that remind a person about a dangerous event but they are rather constant. They make a person to feel stressed and angry most of the time which may not be pleasant especially in a work place (Myers, 2010). These are the most severe symptoms since they do not only affect the individual psychology but also that of the people around him. It is very normal to go through these symptoms after going experiencing a dangerous event. Some people experience them for a short period of time while others may experience them for months if not years.
The Tsunami and the Psychological Effects
A great tsunami occurred on December 24, 2004 and affected a large population from some parts of East Africa and South Asia. It was a natural disaster that did not only take the lives of many people but also destroyed a lot of property. In Sri Lanka (which was the most hit region) alone, 31, 187 people were reported dead, more than four thousand were reported missing, over twenty thousand had been injured and almost half a million people were displaced (Tull, 2009).
As it is normal in many dangerous events, the tsunami was not an exemption as many people were left with psychological problems especially those who witnessed the disaster in Sri Lanka. A study that was carried out about 4 weeks after the tsunami discovered that about 39% of children were suffering from PTSD (Daily News Sri Lanka, 2005). A similar study found out that more than 40% of adolescents and about 20% of adult women showed symptoms of PTSD 4 months later (Daily News Sri Lanka, 2005).
However, the researches do not provide enough information about the long-term effects of the crisis but according to WHO a bigger percentage of people gradually developed symptoms of PTSD due to the event. To verify this claim, an international research group was formed to study the post-tsunami effect.
A study was carried out in Peraliya in Sri Lanka district about one year after the disaster. This is an area where more than 2, 000 people had lost their lives and proximately 450 families had been displaced, and the entire society was in a mess.
A part from the natural disaster, many people had gone through many psychological effects. For instance, about 80% feared for their life because they could still visualize the event that took place. More than 50% had already lost at least one member of the family and they had constant flashback of the event while approximately 80% had lost a friend.
On the other hand, part of the population that was interviewed explained how some of their family members and friends had been seriously injured as a result of the crisis and they could spend sleepless nights. Out of all the participants of the study, 21% experienced PTSD, 16% suffered from severe depression, 30% had relentless anxiety, while more than 22% had somatic signs (Tull, 2009).
Some of the symptoms that were common among many victims of the Tsunami were tension, fear, anxiety, confusion, flashbacks, plus other permanent emotional scars. Other people expressed pessimistic thoughts, withdrawal from social activities, among other physical symptoms.
Some people were able to cope with these psychological effects while others needed professional care. Some of the disaster survivors developed psychiatric disorders including but not limited to anxiety disorders, depression disorders, and PTSD. Most of the victims suffering from PTSD depressed and could not understand what was happening to them (Daily News Sri Lanka, 2005).
They resorted to crying a lot to at least try to ease the pain although this did not work. Some of them wished to die because they could not carry the burden that was imposed on them. It was difficult for family members trying to help those suffering from PTSD because they too were still in agony. It is not always easy to witness the death of a loved one and lead a normal life. What was happening to the post-tsunami victims was normal and it is associated to all dangerous events.
Post-Tsunami Management of PTSD
Many people can recover from PTSD on their own if they are given proper education, they are supported, and their lifestyles modified. The first step in helping a person under PTSD is to help him come into terms with the condition he is going through and to reassure him that what he is going through is normal and is as a result of the traumatic event that he experienced.
Also support from family members, friends, and other professionals helps a person to recover quickly from PTSD. Some anxiety management strategies such as breathing techniques and involvement in social activities have also been known to play a big part in the recovery process. However, patients with severe symptoms of PTSD such as recurrent flashbacks, and lack of sleep and those not responding to PTSD treatment should be referred to a psychiatrist (WHO, 2005).
Most of people who were displaced from tsunami crisis lived in relief camps. Following the disaster, many people were concerned with what had happened and were ready to offer their help in order to help the victims recover from the psychological trauma they went through.
A large number of volunteers all over the world visited these camps to sympathize with the victims. They carried their toolboxes of psychosocial and trauma recovery activities which added confusion and amusement to the people who benefited from their activities as well as the authorities that were concerned with the recovery process.
Psychosocial and mental health programs were initiated in the relief camps by the United States agencies, non-governmental, and governmental institutions to help the victims come into terms with the event.
These programs revived political support, which accelerated the recovery process and many PTSD patients were able to benefit from these programs. In addition, the president of Sri Lanka supported psychological intervention process both financially and psychologically.
He gave these processes the first priority among all the programs that started as part of post-tsunami recovery plan. He realized that if those victims continued to suffer psychologically, no amount of material support would help them come out of the crisis. The president went further to caution all authorities involved in the recovery program to make sure that all personnel hired to conduct the post-trauma counseling were qualified and had enough experience (WHO, 2005).
This is for the reason that some people may be so much willing to offer their help but such assistance may sometimes not be professional and may be only based on belief which can engrave the problem instead of solving it. The acronym PTSD and the word psychosocial were used too often and they became part of the post-tsunami recovery plan. They even became the widely used terms by both politicians and news columnists.
As a team, we also took part in helping the internally displaced persons from the Tsunami. We organized a small fund rising within the school compound where we collected money, clothing as well as food. We visited the victims at the camps and donated some of the material things we had managed to collect and went a head to talk with then.
We played with the children who looked depressed to help them come to terms with their predicament. Since we could not offer any professional psychological help, we just had a general talk with some of the victims and assured them that, they are people out there who care for them and a ready to offer a should to cry on.
The Theory of Psychoanalysis
From research, it has been found that psychoanalysis forms part of the recovery treatment for people under PTSD. This theory was first developed by Sigmund Freud. He is one of the ancient psychologists. The aim of this theory was to study the psychological functioning of human beings and their behavior. Fraud established clinical procedures that would be used to treat mentally ill persons. According to him, individual personality is developed from childhood experiences.
The aim of this therapy was to convey reserved thoughts and mind-set into consciousness in order to free the patient from suffering recurring fuzzy emotions. These reserved thoughts and feelings are brought to consciousness by encouraging a conversation between the doctor and the patient. Patients are encouraged to talk freely and express their dreams and experiences (Asiado, 2007).
According to Freud, psychoanalysis is a process used to treat individuals suffering from psychological problems. He called it “The doctor’s ‘treatment’ and it involves eliciting repressed memories from the patient by interpreting the responses to his questions” (Asiado, 2007).
He observed that a person suffering from psychology problems would be encouraged to re-live previous experience and this would be used as a technique for treatment. The theory involves intervention such as confronting and illuminating the patient’s pathological suspicions, desires, and guilt. Through analysis of individual’s conflicts, psychoanalysis treatment can be used to prove that patients’ unconsciousness is the worst threat of causing symptoms.
This progression assists in determining solutions for the reticent conflicts. In the psyche, the interpretation of Dreams, Freud proposed that dreams can be used to demonstrate the judgment of the unconscious mind. He described dreams as the noble road to the unconscious. In the unconscious mind painful memories are repressed but can be accessed through psychoanalysis treatment.
Conclusion
PTSD can affect, children, adolescent, and even adults. It knows no borders and affects everyone including soldiers who are believed to be the ‘hardest’ persons. Some of the symptoms of PTSD include: recurrent flashbacks, anxiety, depression, insomnia, bad dreams, and pessimistic thought.
They are people who exhibit these symptoms for a very short period of time while others continue to suffer for months if not years. An example of a dangerous event that left many people with PTSD is the great Tsunami of 2004. Apart from the physical damage that resulted from this event, many people suffered from psychological disorders including PTSD.
Children, adolescents, and adults were displaced and were sheltered in relief camps. Some of the symptoms exhibited by the individuals suffering from PTSD included flashbacks, depression, stress, anxiety, loss of self control, pessimist thoughts, and many more. Most of the people who were displaced were sheltered in relief camps where they received both local and international visitors who sympathized with their predicament.
This is where many non-governmental, governmental and U.S. agencies offered their assistance to the victims. They were given both material support and psychological support. Psychological intervention programs were initiated with the support of the president of Sri Lanka to help the people who were suffering from PTSD. The psychological treatment which they received was based on the psychoanalysis theory developed by Sigmund Freud.
Reference List
Asiado, T. (2007). Sigmund Freud and His Couch. Web.
Daily News, Sri Lanka (2005). Editorial: The Primacy of Mental Health Protection. (12 February 2005). Colombo 10: Lake House Press.
Myers, D.G. (2010). Psychology (9th ed.). New York, NY: Worth Publishers
Tull, M. (2009). The Psychological Impact of the 2004 Tsunami. Web.
WHO (2005). Psychosocial Care of Tsunami-Affected Populations. PDF File. Web.
Figure 1. Japanese tsunami (Japanese tsunami 2011).
Tsunami is one of the most dangerous large-scale hazards. It is chosen as a primary topic for the essay, as it is the most hazardous and unpredictable natural phenomenon. Despite the rapid development of technology, a tsunami is variable. Moreover, a number of victims remain high, as the speed and development of the wave are high, and only some people can react quickly and evacuate from a dangerous zone. Consequently, a considerable magnitude and power of the wave destroys everything, which occurs on its way.
Figure 1 presents a devastating impact of the tsunami on the Japanese city, Minamasanriku (Japanese tsunami 2011). This disaster expectedly happened in 2011 (Reuters in Seattle 2015). The photograph displays the power and ability of the nature to destroy the whole city in a short period.
However, it has to be mentioned that this tsunami not only lead to the socio-demographic and economic problems, but also to the ecological issues. As some of the debris, such as electronics, car wrecks, and sports equipment still floats in the Pacific Ocean, the Ocean’s ecology is in danger (Reuters in Seattle 2015). Moreover, this fact causes problems to the United States of America, as some of the wreckages appear close to its coastline (Reuters in Seattle 2015).
As for the geoscientific origin of a tsunami, the process is complicated, as the intensity and magnitude depend on various parameters. Firstly, the source of the volcanic eruption has to be understood, as this natural phenomenon is one of the primary causes of a tsunami. Figure 2 displays the influence of volcanic eruption on tsunami formation (Volcanic eruption n.d.). A release of magma occurs due to the extreme density of magma and other gasses under the Earth’s crust (Masters 2012).
It could be seen high volumes of debris, which are crashing into the sea with the rapidly excavating speed (Volcanic eruption n.d.). This act causes a production of elevating capacities of energy aimed at the water surface. It is a primary cause of tsunami formation, as the pressure involves a movement of high volumes of water towards the shore. Even though a volcanic eruption is a leading cause of tsunami, the gigantic waves might occur due to the earthquakes and landslides.
The earthquake occurs due to the rapid release of accrued pressure in the crust of the Earth. A primary cause of it is ‘the relatively slow motion of lithosphere plates’ (Levin & Nosov 2009, p. 44). The epicenter of the earthquake takes place where a dislocation happens due to the remaining fault on the surface of one or more platitudes (Levin & Nosov 2009). As plates move, the surface of the Ocean experiences fluctuations and pressure, which leads to the tsunami development.
There are several types of tsunami regarding their geographical occurrence such as regional, local, and distant. Earthquakes generate all of these types (Mercado-Irizarry & Liu 2006). However, other geological changes such as volcano eruption might be considered as possible causes of this natural phenomenon. The local tsunamis have a travel time of maximum 24 minutes (Mercado-Irizarry & Liu 2006).
One of the examples of a tsunami is the disaster, which took place on Virgin Islands in 1867 (USC Tsunami Research Group 2005). Two waves crashed into the shore one after another with only ten minutes interval between them (USC Tsunami Research Group 2005). The population of the island was not able to respond quickly to the possible hazards. However, local tsunami attacks continue, as at the same time the island St. Croix was hit by two giant tsunami waves.
According to the eyewitnesses, the waves were around 7.6 meters high and caused severe damage to the island, as they were unexpected (USC Tsunami Research Group 2005). It could be concluded that local tsunamis are the most dangerous and are a reason for the significant amount of deaths, as the travel time of the wave is rather fast. In this case, the local government is illegible to contact and warn the inhabitants on time.
Figure 3. Tsunami in the Indian Ocean (Tsunami in the Indian Ocean 2013).
Regional and distant tsunamis are less dangerous, as they reach the coastline in more than 24 minutes (Mercado-Irizarry & Liu 2006). It could be said that regional tsunamis are less dangerous, as they affect only limited shorelines. However, even though the evacuation time is rather high, distant tsunamis are considered as the most hazardous one to the humankind. The destructive power is great, as the wave gains rapid speed from its generation until it crashes into the shoreline.
Furthermore, its detrimental effect continues to 1,000 kilometers from the epicenter (International Tsunami Information Center 2015). One of the example of distant tsunami aggression happened in the Indian Ocean in 2004 (International Tsunami Information Center 2015).
The primary cause of the massive tsunami was the earthquake of 9.8 magnitude (International Tsunami Information Center 2015). The power of the wave was so incredibly high, as it ruined a significant amount of settlements and caused death to thousands of people. Figure 3 displays the moment right before the shore get swallowed by the giant wave (Tsunami in the Indian Ocean 2013). The city seems tiny compared to the tsunami wave. The outcome is rather predictable, as the speed and height of the wave can be assumed.
In conclusion, it could be said that it is vital to understand a geological origin of a tsunami. There are two primary reasons for tsunami such as an earthquake and volcanic eruption. This knowledge will help avoid a big amount of victims after large-scale natural hazards. It could be said that tsunami is one of the most destructive natural forces, which exist on the planet Earth.
It could be understood from the pictures presented above that tsunami is a real danger for the humankind. With the high frequency of its occurrence, human beings and other animals could be vanished from the surface of the world.
Reference List
International Tsunami Information Center 2015, Tsunami classification.
Tsunami is a huge wave of water forming temporally valleys and mountains that hit a shoreline and hence causing a lot of destruction on the inland. Tsunami generally is mainly caused by huge vertical water displacement. This displacement comes about s a result creation of volcanic eruptions, fault movements, meteorite impacts and landslides. They are more often than not usually caused by very stern earthquakes, most particularly those that crop up at subduction regions. Subduction entails vertical movements as the sub ducting plate goes downhill and superseding plate goes upper direction.
It is very difficult to identify the Tsunami waves at the center of the ocean. When these waves approach the shoreline it is easily identified as a result of creation of huge wave and water piles. Usually the water volumes piles up closer to the shoreline for the reason that tsunami waves move more rapidly in subterranean waters than in superficial water. Tsunamis are in most case accompanied by in a chain of waves, not accompanied by a single wave. Tsunami waves are usually squeezed closer to the coast, the wave power energy is aimed upward and wavelength reduced, rising the wave heights significantly. Tsunami waves are capable of reaching about thirty meters height. This kind of tsunami waves mostly takes place in the regions of Pacific Ocean, affecting regions such as Japan, Hawaii, Indonesia and Alaska. Detectors around these regions specifically in the west coast of the USA help in the process of tracking tsunami. National government Weather Service station and NOAA have come up with a forecasting system technology that approximates the amplitude strength of the tsunami wave and furthermore the estimate the arrival time for most vulnerable regions. Professionals use source of information from the investigators to establish the tsunami wave speed, and hence warning the vulnerable community on the early before the disaster on emergency measure need to put in place to help to mitigate the problem (Hsu, pg 100).
Scientific Causes of Tsunami
Scientifically tsunami is caused by the water which is impelled afar the interior of the underwater commotion, the change in this water levels move at the speed of about four hundred miles per sixty minutes through the ocean. The variation in the levels of water in the ocean moving away from the interrupted epicenter, in consecutive water masses, slows down as it approaches off show areas of the ocean.
The moving water usually forms temporary valleys and mountains. These temporally water valleys or mountains move over a distance downward of eighteen thousand feet at speed of five hundred and twenty mph, slowing to a depth of three thousand feet at a speed of two hundred. The slowing movement decrease to a distance downward of sixty feet at a speed of thirty mph. the water displacement movement becomes extremely vivid and the wave heightens as a result of the slowing effect.
Tsunamis typically move large volume of waters; and for that the tsunami wave might not peak as a regular wave does. In condition that a submerged valley was formed at the center of the ocean, the water is always drawdown away from shows, hence the landscape underwater exposed. On the other hand in condition that an underwater mountain was formed by landslide, volcano, earthquake or meteorite, a vivid increase in water volumes and levels will be formed hence results a tsunami that sluices the inland. The waves created by tsunami regularly ‘runs up’ merely about fifty feet above sea level. The supreme run-up is created by or seismic events or volcanic eruptions near to the coast. Flooding takes longer periods in more landlocked regions, with open land giving way for water to move back to the ocean, the water height and volumes can take months to go back to normal.
Tsunami waves, which are ten times with stronger than wind velocity waves last for periods. Gravity forces play a significant function in tsunamis activity, nevertheless, as dislodged water finds their way to cling and level out in uniform manner to the earth surface. Gravity force draws the displaced temporally mountain of waters in the direction of the middle earth destructing the temporally mountain of water as it moves. Different from an entity wave combating the gravitational force pull of the planet moon, a tsunami activity or occurrence in the Ocean is influenced primarily by the gravitational force of the earth. A tsunami wave length peaks in the condition that shoreline topography influences the occurrences; solar and wind gravity has slight conspicuous impact on a tsunami wave. Following water displacement process by earth resulting to tsunami, the ocean waters tries to recover its equilibrium position to the middle of earth, and hence the tsunami activity showers over space although the tsunami wave loses slight power.
The speed by which a tsunami wave disperses is difficult to instantaneously measure, as it relays on the strength with which the ocean waters was primarily displaced. In overall, tsunamis is characterized a fifth-mile wavelength which occurs in a duration that takes one hour between crests. This long duration of tsunami wavelength reduces the ratio between the ocean depth and wavelength. For the reason that tsunami waves are characterized by minimum ratio between depth and wavelength, they act in very subterranean water as waves act in low water: they move long regions with less power loss.
For the reason that tsunami waves are created by pressure, sensors of pressure secured at the floor of ocean can convey warning signs to buoys hovering on the surface of water indicating an increase in pressure. Tsunami an occurrence is illustrated by the pressure increase in water. In addition it is illustrated by lengthened episodes between waves. In condition the third major sign, seismic action, is on, the tsunami technology center receiving the hints from the buoy by the use of satellite will more often than not issue a tsunami admonition. Furthermore in the condition that the initial motion discovered is a water valley then investigators have information that the plates sub positioned downward, for mining a valley on the floors of ocean. Similarly, in the condition that the initial motion discovered is a water mountain, then investigators information of shifting plates for mining a mountain on the floor of ocean.
It is very necessary to take in consideration that the behavior of the ocean after seismic process is very difficult to understand. Earth movements and substantial landslides can result straight tsunamis, the initial tsunami wave of which is not essentially the supreme. Every tsunami is characterized by different process of dissipating waves. The level of water from the initial tsunami mighty halt to usual levels, merely to treacherously increase once more as aftershocks, tremors, volcanoes or landslides, in diverse areas have result in fresh tsunamis in the minutes and hours following the first tsunami was created. Scientific investigators may clearly detect the diverse wave models while spectators on the earth ground can not (Abbott pg 82).
The Causes and Impacts of 2004 Tsunami
The origin of the tidal waves that occurred at 500 miles per sixty minutes across the Indian Ocean on the twenty seven of December two thousand and four was very simple.
The Eurasian and Australian tectonic plates positioned at subterranean, when the Ocean was moved, shaking the under waters numerous meters, and dislocated large volumes of water. This created a tsunami or sequence of big waves, to form and move away, searching for a place to burn up their power energy.
At this phase, the tsunami waves would be not more than 60 or 50 or centimeters far above the ground, difficult to being identified as they moved under ships in the open ocean. They were discovered 30 minutes later, in the Andaman Islands, after 99 minutes in Thailand and after duration of 2 hours in Sri Lanka, prior to at last running themselves out on the shoreline of Somalia coast after a period of some 7 hours (Kious pg 88).
As wave moved towards the shallows regions, reaching land for instance , the speed of a tidal wave reduced at the frontline and the moving water at the back rears up, creating a barrier that was about ten meters height ; at that point the tsunami wave approached its destination, although it had some mission to accomplish further.
In near to the ground lying on earth surface, the tsunami waves pushed a number of kilometers inland. Since one a cubic meter of water wave weighs about one thousand kilograms, this tsunami wave smashed and wrecked everything on is way on the twenty six of December 2004. When the tsunami wave retreats back to the deeper sea, it took much of what it had damaged. Many populaces were carried away, their bodies were not found and they did not return home again.
The tsunami wave claimed over 150,000 people in Indonesia, in addition 31,000 people perished in Sri Lanka, comprising the globes’ worst train catastrophe which claimed more than a thousand lives. Furthermore it rendered 299 homeless and Twenty Maldives homeless. The negative impact caused by 2004 tsunami was so severe that in total an estimate of not less than 250,000 lives perished in the catastrophe. Furthermore Indonesia many poor communities depending on sea for their living were completely destroyed in Indonesia and Sri Lanka.Patong and Khao Lak beach restaurants were total destroyed excluding Patong of which the waves occurred after it was deserted in Thailand.
The tsunami incident caused a lot for damages to the numerous small business undertakers; bar owners, street traders, and fishermen who lost everything they had accomplished. These business operations were not insured; since Asian countries were still developing not equip with such insurance services. The community affected by the tsunami, had no otherwise but to start a new life without getting any compensation from the insurance company (Kious pg 56).
Economic experts stated that Indonesia was the most affected country of all the Asian countries which were hit by the calamity. The cost of running the recovery phase of the disaster is estimated at four billion United States of American dollars over the next 5 years. The International Labor Organization on the other hand estimates that there has been a loss of one million jobs in both Sri Lanka and Indonesia. The region near the coast of this country was the worst hit and many buildings including luxurious hotels located on the coastline were severely destroyed. This has generally impacted on the trade and industrial stability of this country. The fishing industry which employs two thirds of the Indonesian population was also hit hard since the Indian islands of Nicobar and Andaman were seriously damaged; over seventy percent of jetties were destroyed (Abbott, Leon pg 98).
This disaster politically brought together many different nations who were willing to assist the effected countries for instance; the Russians contributed one million rubles. The Britons donated ten point seven billion pounds, and the Americans donated 195 million which was used in the relief process in the regions affected by the tsunami.
Socially the disaster united people from different cultures, countries, regions and nations, to work together by setting aside their difference. If these kinds of incidents can bring together habitual enemies, on the other hand in a few words, in a unlike views, indisputably, there is little positive impacts emerging from very destructive disasters.
The Tsunami disaster that hit the Asian coast in the year two thousands and four resulted to an intensive humanitarian crisis. The total number of people who died because of this calamity stands at over one fifty thousands lives and immeasurable resultant suffering of the victims who survived. Munich Re which is global insurance giant estimated the loss obtained from this calamity to be at ten billion euros. The only hope for the affected countries is that the disaster affected severely the undeveloped areas of the affected countries and no major damages occurred to the industrial regions of this region (Jayatilleke Bandara and Athula Naranpanawa pg 66).
Other Incidences of Tsunami
There was also reported subduction earth movement which was very powerful in Chile in May nineteen sixty ,which resulted after three different tsunami waves that killed about one thousand Chileans ,furthermore millions valued properties were destroyed. In addition in the disaster rendered people homeless and killed many people in Japan and Hawaii, a lot of property were also destroyed by the tsunami. In nineteen ninety a tsunami occurred that caused a lot of damage destroying properties in Nicaragua, in South America coast. Furthermore a tsunami inundated the whole peninsula in Hokkaido, in nineteen ninety three (Kious pg 44).
Conclusion
Circumstances are coming up in the globe near us that might in the long run cause a massive disparaging tsunami that possibly will affect most important states and towns bordering the Indian, pacific and Atlantic Ocean. The volcanic land mass La Palma which is to North of Africa Canaries is perched to extent the massive tsunami wave to the United States of American Eastern Shoreline. The North America east shoreline may possibly slip into the Ocean, it has happened in the earlier period, smudging Europe civilization with the destructive tsunami. In addition the pervasive Bolide tsunamis, which come as a result of the negative impacts of outer space objects, are very difficult to predict and avoid and hence very difficulty to mitigate the disaster. There is very high probability that more or one or of these circumstances must come to take place in the near future. The problem is, are we equip with advance technologies to mitigate these disaster and save lives and property early enough before they happened?
Works Cited
Abbott, Leon. The causes and impacts of natural disasters, USA: McGraw-Hill, 2005.
Hsu, Tom. The study of physical, space and earth science, London: Sage, 2003.
Jayatilleke Bandara and Athula Naranpanawa. The Economic Effects of the Asian Tsunami on the ‘Tear Drop in the Indian Ocean’, South Asia Economic Journal, 8 (1): 65-68, 2007.
Kious, J. The study of Tsunamis tectonic dynamics, USA: Wiley publication, 1999.
The question that was selected as the topic for discussion in this work is “How did oceanographers figure out the physical nature of tsunami?” The importance of this question is proved by the numerous cases of tsunami that have been hitting Asia over the recent years (GITEWS, 2009). Accordingly, for us as students it is of crucial importance to know how tsunamis develop and how the oceanographers have managed to study the nature of tsunami. As well, it is necessary for us to know about the specific equipment used in tsunami research and the means of predicting tsunami and fighting its effects. Thus, the current paper starts with providing the background information on tsunami that can help introduce the topic to the wide audience. Next, the paper moves on to discussing the methods and equipment oceanographers used to study the nature of tsunami. Finally, the paper concludes with new challenges that appeared in the study of the physical nature of tsunami.
Tsunami Background Information
However, to study the tsunami research equipment it is necessary first to realize what tsunami is and how it is formed. Thus, Nelson (2009) defines tsunami as “a very long-wavelength wave of water that is generated by sudden displacement of the seafloor or disruption of any body of standing water”. Tsunamis are characterized by wave length, height, amplitude, and velocity. According to Nelson (2009), wave length is the distance between similar points of the wave; the concepts of tsunami wave height and amplitude are interconnected, as the height is the distance between tsunami’s trough and peak, while the amplitude of tsunami refers to the height of this wave above the level of the still water (Nelson, 2009).
Although scholars often refer to tsunamis as “seismic sea waves”, Nelson (2009) argues that such a definition is not appropriate because tsunamis can have other causes of emergence than earthquake and other seismic activities. The major natural reasons that cause tsunamis include earthquakes, volcanic eruptions, landslides, underwater explosions, and meteorite impacts (Nelson, 2009). Also, the phenomena called Drawdown and Run-up characterize the deceptive nature of tsunamis.
Nelson (2009) describes tsunami drawdown as a situation when the trough of the tsunami hits the coast prior to the peak of the wave. Usually it is perceived as the decrease of the sea level and is not associated with danger. However, instantly the peak of tsunami heats and usually people and facilities on the coast turn out to be unprepared for this. Thus, the consequences of tsunamis are rather hazardous, especially when regions facing the threats of tsunami fail to carry out preventive measures and citizens’ education in regard of tsunami safety rules (Borrero, 2005, p. 312; Liu, 2000, p. 2). Drawing from this, the research of the physical nature of tsunami has always been considered a vital need for the safety of the humanity and for saving of thousands of lives.
Account on Tsunami Studies
Needless to say, oceanographers paid considerable attention to the diligent study of the physical nature of tsunami. The first step in this process was the outline of the major areas of interest and establishment of the appropriate methodologies and sets of equipment to explore them. Of course, the initial stages of tsunami research were rather based on people’s impression and thoughts about the possible nature of the disaster, as well as observations of this natural disaster (GITEWS, 2009). Nevertheless, the detailed and focused research on tsunami waves became possible only when oceanography as a science received the powerful impact for its development after the immense technological progress of the 19th century. The advances in the oceanographic equipment allowed scholars not only get pictures and sound recordings of the ocean processes, but also get into the ocean depth and explore the bottom, its nature, and the composition directly (Liu, 2000, p. 8). This was a great achievement in the way of studying the physical nature of tsunami waves as far as direct study of the backgrounds in which tsunamis are generated cannot be replaced by any artificially created and laboratory research projects.
Further on, the data provided by GITEWS (2009) allow speaking of the more serious approach to tsunami research that is developed by scholars. GITEWS (2009) presents a detailed account on the methods of tsunami study and early warning used by the joint Indonesian and German team of scholars to protect the countries of Indian Ocean region from tsunamis. The study of the nature of these destructing waves, according to GITEWS (2009), involved the use of modern oceanographic equipment together with the satellite, both earth-based and orbital, technology. Accordingly, the major approaches that scholars used to go about the study of the physical nature of tsunami included the seismological study, sound recording procedures (Liu, 2000, p. 10), satellite communications processes, and the systems of warning the regions potentially subjected to tsunami dangers (GITEWS, 2009).
Oceanographic Equipment Used for Tsunami Research
Naturally, the oceanographers had specific equipment in their disposal to study the physical nature and causes of tsunami waves. This equipment ranged from the simplest computer programs to monitor the development of tsunamis to the complex satellite technology used for both tsunami study and development of the early warning systems (GITEWS, 2009). For example, Liu (2000) discusses the wave research equipment that consists of the wave tank and the wave generator that allowed the oceanographers to study waves in a three-dimensional large research facility and understand the physical nature of tsunami (p. 5). The essence of this equipment laid in the creation of the artificial environment where tsunamis could be generated by the earthquake and volcanic eruption simulations without the danger for the people and facilities around (Liu, 2000, pp. 6 – 7).
Needless to say, such research did not provide all the information about tsunami’s physical nature that the natural study would provide, but at least it allowed scholars to make assumptions about the tsunami generation processes and possible ways of reaction towards tsunami threats (Liu, 2000, pp. 6 – 7). Further on, NOAA (2009) singles out a number of other equipment pieces including the computer systems of image modeling of the ocean bed and the scholarly surveys of oceanographic and seismic data that widened oceanographic knowledge on tsunami. As well, the two kinds of bottom imaging equipment were of great use for oceanographers including the TV and sound-generated imaging systems (NOAA, 2009). Water depth sounders and bottom samplers also provided considerable information about the physical nature of tsunami.
Finally, oceanographers used seismic and land-surveying devices together with tide gages installed in harbors to study the physical nature of tsunami waves (NOAA, 2009). Used in conjunction with the satellite technology like the GPS Altimetry Stations and Buoys argued about by GITEWS (2009), these pieces of equipment allowed oceanographers to not only study the physical nature of tsunami waves, but also prepare certain means of warning against tsunamis. As the experience of Indonesia showed in 2004, the warning system might have been rather useful in that case. Therefore, the use of oceanographic equipment to study the physical nature of tsunami contributes not only to the development of oceanography as a science but to the process of protecting the mankind from the threats of tsunami waves.
Results of Research on Physical Nature of Tsunami
As a result of this research work, oceanographers have managed to find out the considerable amount of data that characterize the physical nature of tsunami. For example, one of the basic facts about tsunami waves is, according to Nelson (2009), that the average tsunami wave length exceeds the average length of an ordinary ocean wave almost five thousand times and reaches the maximum of 500 kilometers (Nelson, 2009). Further on, oceanographers have noted that the height and the amplitude of tsunami waves depend upon the nature and the power of the tsunami-causing factor, while the velocity, i. e. the wave speed, often reaches the level of 950 km/h, which exceeds the ordinary ocean wave speed 10 times (Nelson, 2009).
Oceanographers also managed to dismantle the myth about tsunamis’ being produced by the seismic activity of the ocean bottom only. The research on the physical nature of tsunami revealed that apart from underwater earthquakes, tsunamis can be generated by volcanic eruptions, explosions, landslides, and effects of meteorite crashes into the ocean bottom. According to Nelson (2009), volcanic eruptions become the causes of tsunamis if the pyroclastic flows are rather powerful and able to displace large masses of water so that the latter should hit the coast. The point about the meteorite effects and underwater explosions is the same, as any stress of the water masses causes the latter to move. Combined with the depth of the water, the direction of the currents, and wind, the displaced water mass starts moving abruptly and acquires speed in transit to achieve the destructive power on reaching the coast. Finally, oceanographers nowadays refer to tsunamis as shallow-water waves, which means that tsunamis have small ration of wave length and depths and the deepest waves, which differs tsunamis from ordinary ocean waves caused by wind blowing over the ocean surface (Nelson, 2009).
New Questions on the Topic
However, after oceanographers had managed to answer the question about the physical nature of tsunami waves, a number of other related questions appeared for further scholarly consideration. For example, NOAA (2009) stresses the weakness of oceanography in temporary inability to identify the precise cause of tsunami in case if two or more factors can be the possible causes. When a tsunami happens in a region characterized by a high earthquake risk and a possibility of either volcano or other underwater explosions, there is currently no oceanographic equipment to state which one was the actual tsunami cause. To be more succinct, the new related questions are:
How a precise cause of tsunami can be identified?
Is tsunami possible in regions not displaying any of the above listed tsunami causing factors?
References
Borrero, J. (2005). Field Survey of Northern Sumatra and Banda Aceh, Indonesia after the Tsunami and Earthquake of 2004. Seismological Research Letters, 76(3), 312 – 320.
GITEWS. (2009). Tsunami Early Warning System. Web.
Liu, P. (2000). Report for a National Science Foundation Workshop for Tsunami Research Facilities. Cornell University, 1 – 10.
