Oceanic Waves-Tsunami

`1) Oceanic waves mean the forward movements of the ocean’s water caused by oscillation of water particles by frictional drag of wind over the Earth’s surface. It can be caused by the movement of Earth’s crust aka an earthquake. Like every wave, oceanic waves have highest and lowest points. The peak of thewave is called crest while the lowest point is called trough. The wavelength is the horizontal distance between two troughs or crests. 2)The Largest and most dangerous of oceanic waves is called tsunami or tidal waves. It’s wave could reach up to thousands of feet tall.

3)Tsunami is word originated from japan, and it’s equivalent in English is called “seismic sea waves. ” There are many factors causing Tsunami. Most tsunamis that has occured in the past few years are caused by the down drop or upthrust of the Earh’s crust that results in Earthquke. It can also a large-scale undersea landslide, a high degree of submarine volcanic eruption, and can also be caused by the impact of large meteor in the sea. 4)The most dreadful Earthquake ever recorded was the 2004 Indian Ocean Tsuanmi, with more than 200,000 deaths in Asia. a).

5)There’s no possible way to prevent a Tsunami since it is a natural disaster. But over the years, people have been working hard to find an effective way to predict this calamity and how to reduce the effects as well. The most common way to predict if a tsunami is by using seismograph. Seismograph is a device used to measure the magnitute of an Earthquake. This device exist since the ancient times by the Chinese people and has saved lives of numerous people. The current form is much more compact and reliable than the old one, thanks to the modern technology we have now.

The picture beside is a photo of a modern seismograph used by the British Geological Survey. Seismograph is handy and provide quick and accurate results. It also provides a wide range of earthquake results so after an earthquake happens, the goverment could predict the casualties, and whether another earthquake or a tsunami is coming. People had grown to rely on this device. When a large scale earthquake is coming, the goverment issued an alarm and told the citizens to evacuate. There’s some disadvantages of using seismograph.

6)Reports has shown that tsince the Hawaii’s Pacific Tsunami Warning Center was established in 1948, more than half of it’s warnings are false. This caused uneccessary panic to the citizens of the surroundings city. Lots of riots and crimes happen during their panicked state. After every warning, the goverment also evacuated the citizens to a safe place. This costs a lot and so evacuation caused by false warnings caused the state much. ——————————————————–Footnote—————————————————————– 1. “Ocean Waves – Learn About Ocean Waves.

” Geography Home Page – Geography at About. com. Web. 01 May 2011. . 2. “Tsunami – How a Tsunami Happens. ” Academic Program Pages at Evergreen. Web. 01 May 2011. . 3. “World’s Biggest Tsunami | 1720 Feet-tall – Lituya Bay, Alaska. ” Geology. com – Earth Science News, Maps, Dictionary, Articles, Jobs. Web. 01 May 2011. . 4. “List of Natural Disasters. ” Wikipedia, the Free Encyclopedia. Web. 01 May 2011. . 5. “Savage Earth: Predicting Tsunamis. ” PBS: Public Broadcasting Service. Web. 01 May 2011. . a. “BBC – Humber – Features – Your Quake Stories. ” BBC – Homepage. Web. 04 May 2011.

. 6. “Savage Earth: Predicting Tsunamis. ” PBS: Public Broadcasting Service. Web. 04 May 2011. . 7) Satellite usage to predict Tsunamis are also becoming more popular these last few decades. Satellites are the more complex method used currently. The satellite will capture the movement of an ongoing tsunami and send it back to the government. Some countries like Japan and States has started to use sensors that stays on the seafloor and detect the slight touch of a tsunami passing overhead. These bottom-pressure sensors are connected by a cable stretching out from its coastlines.

When the sensors sensed a tsunami going on, the buoy anchored nearest will relay a warning message to the shore via the satellite. b) 8) Using satellite to predict tsunamis is very accurate since it detects an ongoing tsunami and not predicts which sometimes is highly inaccurate. Depending on the locations of the sensor and the shores, it could provide hours of time for the citizens to evacuate to a safe place. The disadvantages are satellites and sensors are high tech products which are expensive to make and maintained. So it’s not available to some poor or undeveloped country.

As I have said before, the time given to react to the warnings depends on the location of the sensors and tsunami. That means if the sensor catches it late or if it’s located near the shores, there’ll be little to no time to react, sometimes only 1-3 minutes until the impact, and so the information is not very helpful or can be deemed as useless. 9) The picture beside shows how the whole system worked. Sea floor sensors will send signals to a buoy, which will transmit to a satellite, and the satellite will transmit it back to the warning center. 10) Economical Factor:

Tsunami causes the country’s economics to decrease. This is because a Tsunami will destroy anything on its path and the government has to re-build it which costs a lot. The government also has to aid the evacuated citizens and provide them with their basic needs such as food, clothes and shelter. The neighboring countries will usually give donations and offer help to the victim country which certainly is very useful. But it is a fact that the country suffers great loss from a tsunami. Social Factor: People that evacuated suffer the most mentally.

They had just experience one of the most deadly disaster. People lose everything in that disaster. Their homes, business and probably some of their families and friends. They have to start all over again in a new place which is hard to accept by some people and can lead to mental problems like craziness.

The aftershock of those victims may last years. They may get trauma and can’t move on with their life. ————————————————————Footnote————————————————————– 7.

“Tsunami-Predicting Tsunami. ” The International Tsunami Warning System. Web. 4 May 2011. . 8. “Tsunami Warning System. ” Wikipedia, the Free Encyclopedia. Web. 04 May 2011. . 9. & b) “Deep Ocean Tsunami Detection Buoys. ” Bureau of Meteorology – Home Page. Web. 04 May 2011. . 10. “Tsunamis and the International Response: Economic, Social and Environmental Dimensions. ” CSA. Web. 04 May 2011. . Environmental Factor: c) Tsunami affects the environment greatly. It destroys everything on its path.