TsunamiPPT学习课件学习.pptx

《TsunamiPPT学习课件学习.pptx》由会员分享，可在线阅读，更多相关《TsunamiPPT学习课件学习.pptx（12页珍藏版）》请在得力文库 - 分享文档赚钱的网站上搜索。

1、What Is A Tsunami?A tsunami is a series of water waves caused by the displacement of a large volume of a body of water such as an ocean.4 kinds of tsunami:1.storm surge caused by the change of meteorological phenomena;2.volcanic tsunami caused by volcanic eruption;3.hill-creep tsunami caused by the

2、seabed landslide;4.seismic tsunami caused by seabed earthquake.第1页/共12页第一页，编辑于星期日：一点 二十二分。Cause Earthquakes,volcanic eruptions and other underwater explosions(including detonations of underwaternuclear devices),landslides and other mass movements,meteorite ocean impacts or similar impact events,and

3、other disturbances above or below water all have the potential to generate a tsunami.第2页/共12页第二页，编辑于星期日：一点 二十二分。theory第3页/共12页第三页，编辑于星期日：一点 二十二分。Some meteorological(与气象有关的）conditions,such as deep depressions that cause tropical cyclones,can generate a storm surge,called a meteotsunami,which can rais

4、e tides several metres above normal levels.The displacement comes from low atmospheric pressure within the centre of the depression.As these storm surges reach shore,they may resemble(though are not)tsunamis,inundating vast areas of land.Such a storm surge inundated Burma in May 2008.第4页/共12页第四页，编辑于

5、星期日：一点 二十二分。characteristicsWhen the wave enters shallow water,it slows down and its amplitude(height)increases.The wave further slows and amplifies as it hits land.Only the largest waves crestWhen the tsunamis wave peak reaches the shore,the resulting temporary rise in sea level is termed run up.Run

6、 up is measured in metres above a reference sea level.16 A large tsunami may feature multiple waves arriving over a period of hours,with significant time between the wave crests.The first wave to reach the shore may not have the highest run up.第5页/共12页第五页，编辑于星期日：一点 二十二分。Warnings and predictionsA tsu

7、nami cannot be precisely predicted,even if the magnitude and location of an earthquake is knownHowever,there are some warning signs of an impending tsunami,and automated systems can provide warnings immediately after an earthquake in time to save livesOne of the most successful systems uses bottom p

8、ressure sensors that are attached to buoys.Some zoologists hypothesise that some animal species have an ability to sense subsonic Rayleigh waves from an earthquake or a tsunami However,the evidence is controversial and is not widely accepted.The ocean receding or rising unusually rapidlyNot far from

9、 the shore of the ocean,the water surface immediately turn to white,and suddenly appeared a long bright wall of water Ships in neritic province suddenly bumps up and down dramaticallySuddenly from the ocean came the great unusual sound,especially alarming in the night.第6页/共12页第六页，编辑于星期日：一点 二十二分。How

10、To Escape From A Tsunami?Step 1:Be aware of natural warnings.Tsunamis are caused by earthquakes on the oceans floor.However,some inland areas will feel the quake days before a Tsunami hits.This was the case in Chile in 1960.After feeling the tremors,many people took action and headed to high ground

11、early.Step 2:Keep a radio on hand at all times and take official warnings seriously.People who live in areas prone to Tsunamis must always follow official warnings and directions right away.Step3:Abandon Belongings;Save your life,not your possessions.Dont take anything with you except a prepared eme

12、rgency kit.When leaving an area that is expecting a Tsunami,getting out quickly is vital to survival.Just get yourself and your family and go.Step4:Go to an Upper Floor or Roof of a Building Only if trapped and unable to reach high ground,go to an upper story of a sturdy building or get on its roof.

13、Step5:Dont Count on the Roads Stay away from washed out roads.Roads are some of the first things that disappear in a Tsunami.Plan an alternate escape route Step6:Climb a Tree As a last resort,climb up a strong tree if trapped on low ground.Step7:Climb onto Something that Floats If swept up by a tsun

14、ami,look for something to use as a raft.Step8:Expect the Waves to Leave Debris Grab on to large floating debris and hang on,if you are escaping after the wave hits.You may get injured,but this step could save your life.第7页/共12页第七页，编辑于星期日：一点 二十二分。2004 Indian Ocean tsunamiThe 2004 Indian Ocean earthqu

15、ake and tsunami killed over 200,000 people with many bodies either being lost to the sea or unidentified.According to an article in Geographical magazine(April 2008),the Indian Ocean tsunami of December 26,2004 was not the worst that the region could expect.Professor Costas Synolakis of the Tsunami

16、Research Center which suggests that a future tsunami in the Indian Ocean basin could affect locations such as Madagascar,Singapore,Somalia,Western Australia,and many others.As a weaponThere have been studies and some attempt to create tsunami waves as a weapon.In World War II,the army in New Zealand

17、 trialled explosives in the area of todays Shakespeare Regional Park to create small tsunamis,an attempt which failed.第8页/共12页第八页，编辑于星期日：一点 二十二分。1.A pleasure-boat hit the house.2.The tsunami blooded everything.3.The survivor were waiting for the food.第9页/共12页第九页，编辑于星期日：一点 二十二分。The tsunami blooded the buildings,the airport and anything.第10页/共12页第十页，编辑于星期日：一点 二十二分。The body of the victim were placed at the street,the tent or anywhere after the tsunami.第11页/共12页第十一页，编辑于星期日：一点 二十二分。感谢您的观看。第12页/共12页第十二页，编辑于星期日：一点 二十二分。