Physical knowledge in tsunamis-英文作业代写－r51due

英国essay论文精选范文：“Physical knowledge in tsunamis”，这篇论文讨论了海啸中的物理知识。20世纪以来，世界上发生了七次大海啸，尤其以2004年印尼苏门答腊岛附近海域强烈地震引发的海啸最为严重。海啸是大规模的水波运动，在物理学上属于特长的长波能量传递。其波长比海洋的最大深度还要大。这种波浪运动卷起的海涛，波高可达数十米。这种“水墙”内含极大的能量，冲上陆地后所向披靡，往往造成对生命和财产的毁灭性打击。

Since the 20th century, seven tsunamis have occurred in the world, especially the tsunami caused by the strong earthquake in the waters near Sumatra Island, Indonesia in 2004 is the most serious. The tsunami has become one of the most important natural phenomena in the world due to the wide range of damage, the number of casualties and the most serious natural disaster in the past few centuries. . Here we are concerned about the physical knowledge of the tsunami to do some introduction.

The tsunami is a large-scale wave motion, in physics belongs to the long wave energy transmission. The wavelength is greater than the maximum depth of the ocean. No matter how deep the ocean, waves can spread in the past. This wave movement rolled up the sea waves, wave height of up to tens of meters. This "water wall" contains a great deal of energy. Rushed into the land after the invincible, often resulting in the devastating blow to life and property.

It should be noted that the tsunami is different from the waves and tides: the breeze blows across the ocean, waves, it is generally only in the sea near the ups and downs, the depth involved is not large, fluctuations in amplitude decay with water depth very quickly, the tsunami caused by the earthquake Is the fluctuation of the entire water body from the seabed to the sea surface; the tidal current can flow into the bottom of the ocean, which is the same as the tsunami, but it is caused by the gravity of the moon or the sun. While the tsunami is caused by fracture of the seabed caused by fluctuations. Such as the tsunami in Chile, the formation of the waves, moving thousands of meters still less glory. It shows its great power.

Fluctuations have three characteristic parameters: wave velocity, wavelength, period. Tsunami wave is characterized by fast wave speed, wavelength and long cycle, it is in the ocean migration line, the wavelength can reach tens or hundreds of kilometers, wave height is only about 1m, cycle 2 ~ 200min, the propagation speed of about 500 ~ 1000km / H. The results show that the wave velocity is independent of the wavelength, and only depends on the depth. Visible, the more the tsunami wave near the shallow sea, the slower the spread. According to the average depth of the Indian Ocean can be calculated the spread of the tsunami speed of about 700 ~ 800km / h. While the velocity of the shallow sea near the coast is reduced to about 40km / h. At the same time, because of the tsunami wave length, the entire waveform in the deep ocean does not look "steep", unlike the general Kuangtao the same boat will be high, "throw up", or even difficult to perceive its existence. However, once the tsunami wave into the continental shelf, due to the depth of the shallow shallow, the wave speed is getting smaller and smaller, wave height, like an extremely high water wall suddenly pressed to the land. Leading to devastating disasters. Can be seen that the power of the tsunami is only distributed in the shallow water, it will not cause disasters in the deep ocean. It can be said that the tsunami occurred in the more secure offshore. Therefore, the preparation of the dock or docked at the shore of the vessel in time to open to the contrary, the sea is the right choice.

http://www.51due.net/writing/essay/sample30863.html

In China's vast coastal waters, the distribution of the size of thousands of islands reef beach. From the Miao Island in the Bohai Sea to the Nansha River in the Yellow Sea, Zhoushan Islands in the East China Sea, Taiwan Island and the South China Sea Islands, these islands form a circle around the mainland arc, forming a sea barrier; Japan Kyushu, Ryukyu Islands, as well as the Philippine Islands arch, but also constitute another natural breakwater, against the impact of the tsunami wave of the sea. Combined with broad continental shelf shallow sea bottom frictional resistance, when the tsunami wave from the deep. Sea spread to China's sea area, its energy has rapidly decayed, not constitute a threat.

Frequency below 20Hz sound waves, called infrasound. The infrasound waves brought by the tsunami can even destroy the houses on the shore. Because the velocity of the infrasound wave is greater than the velocity of the great wave caused by the earthquake, it becomes a prelude to the tsunami. It is possible to predict the devastating tsunami by receiving infrasound. Some scientists believe that many animals have been able to escape the tsunami that swept the coast of the Indian Ocean, because they are sensitive to hearing, the sub-sonic induction; and only the frequency of 20 ~ 20000Hz the sound of induction, the infrasound is " , And thus often face the earthquake and tsunami. There is no awareness.

Shortly after the violent tremors, the waves roared to the coast, crossing the fields, swiftly attacking the cities and villages at the seaside, and all of a sudden disappeared in the waves. All the facilities of the harbor, the buildings collapsed by the earthquake, were swept away by the scourge of the raging waves. After the beach on a messy, full of broken wood and human and animal dead bodies. The tsunami disaster to mankind is enormous.

At present, the human catastrophes such as earthquakes, volcanoes and tsunamis can only be prevented or reduced by forecasting and observing, but they can not control their occurrence. In principle, tsunami warnings are much easier to predict than earthquakes, because fluctuations in fluid conductance are much slower than the transmission of seismic waves in solids. And the more close to the shallow sea waves, the slower the spread. Once the seismic monitoring station through the seismic wave transmission to detect the seabed earthquake, and through the relevant mathematical model to calculate the probability of occurrence of the tsunami. The current tsunami warning is theoretically possible. It is mainly through the pressure gauge and acoustic sensors placed in the deep ocean, through the piezoelectric phenomenon of current, the current and the pressure is proportional to. Electric Pulse Start Acoustic Wave Sensor. And by the buoys on the surface to collect sound waves, buoys and then through the satellite data to the ground observation station. In this way, you can monitor the ocean bottom and the tsunami-related various hydrological signals and sea surface fluctuations, with the computer to capture the information with a variety of seismic monitoring system to obtain information on crustal movement to simulate the tsunami may form the location and direction of movement . The tsunami-affected countries are informed in advance of the size of the tsunami, the speed of movement, the areas likely to be hit and the estimated time of arrival. It can be said that tsunami warning is the clever use of electromagnetic waves and mechanical waves and mechanical waves in different media caused by the difference in the speed of time difference, so that the local government to take preventive measures in advance to reduce the tsunami caused by casualties and economic losses.

When the tsunami wave of the tsunami in Chile reached Shanghai, only the tsunami wave height of 15-20 cm was recorded in the Wusongkou tide station. When it reached Guangzhou, Zhaopo Marine Station only detected the weak trace of the tsunami wave. It can be seen, not only China's coastal areas are not prone to tsunami. Is the tsunami occurred in the distant sea will not pose a threat to China's coastal areas. Of course, to strengthen the tsunami mechanism research, accurate forecast and forecast tsunami is still necessary. On the prevention of sudden earthquake tsunami or meaningful.

想要了解更多英国留学资讯或者需要留学生作业辅导，请关注51Due英国论文代写平台，51Due是一家专业的论文代写机构，专业辅导海外留学生的英文论文写作，主要业务有医学Essay代写、Essay代写、paper代写、assignment代写、英国工科毕业论文代写。在这里，51Due致力于为留学生朋友提供高效优质的留学教育辅导服务，为广大留学生提升写作水平，帮助他们达成学业目标。如果您有论文代写需求，可以咨询我们的客服QQ：800020041。