Unit 4 Video Time高中英语课件

VideoTimeTsunami:KillerWaveUnit4

Naturaldisasters1.Watchthevideotoknowabouttsunami;2.Talkaboutthesafetyinstructionsabouttsunami;3.Discussonthereliefworkaftertsunami.LearningobjectivesWhatistsunami?A

tsunami

isaseriesofoceanwavesthatsendssurges(急剧上升)

ofwater,sometimesreachingheightsofover100feet(30.5meters),ontoland.Thesewallsofwatercancausewidespread

destruction

whentheycrashashore.Lead-inTsunamiwavescanstrikeoutofnowhereandcausealotofdestruction.Scientistsstudyandtracktsunamisinordertowarnpeopleandminimizedeaths.Tsunami:KillerwavesWhatCausesaTsunami?Thesewavesarecausedbylarge,underseaearthquakesat

tectonicplateboundaries.Whentheoceanfloorataplateboundaryrisesorfallssuddenly,itdisplacesthewateraboveitandlaunchestherollingwavesthatwillbecomeatsunami.Itmayalsobecausedbyunderwaterlandslidesorvolcaniceruptions.BeforeyouwatchTask1：Readthesentencesabouttheformationandeffectsoftsunamis.Thenmatcheachsentencewiththecorrectpicture.A.Tectonicplatespushtogether.B.Aseriesofwavesexpandsinalldirections.C.Wholesectionsofcitiesaredestroyed.WhileyouwatchA.Tectonicplatespushtogether.B.Aseriesofwavesexpandsinalldirections.C.Wholesectionsofcitiesaredestroyed.Checkyouranswers.A.Tectonicplatespushtogether.B.Aseriesofwavesexpandsinalldirections.C.Wholesectionsofcitiesaredestroyed.Task2：Watchthevideoagainanddecidewhetherthestatementsaretrue(T)orfalse(F).1.Therearefewwarningsignsjustbeforeatsunamihits.2.Atsunamibreaksjustlikeanordinarywavebutisbigger.3.ScientistsatthePacificTsunamiWarningCentermonitortheearth’smovements24hoursadayinordertotracktsunami.TFTFTFLet’swatchthevideoagain.Checkyouranswers.1.Therearefewwarningsignsjustbeforeatsunamihits.2.Atsunamibreaksjustlikeanordinarywavebutisbigger.3.ScientistsatthePacificTsunamiWarningCentermonitortheearth’smovements24hoursadayinordertotracktsunami.TFTFTFAtsunamiwavedoesn’tbreaklikeanordinarywave.1.Therearefewwarningsignsjustbeforeatsunamihits.T2.Atsunamibreaksjustlikeanordinarywavebutisbigger.FAtsunamiwavedoesn’tbreaklikeanordinarywave.3.ScientistsatthePacificTsunamiWarningCentermonitortheearth’smovements24hoursadayinordertotracktsunami.TTask3：Circlethecorrectword(s)ineachsentence.1.Anearthquakeoccurswhenplatesbelowtheearth’ssurfacepushtogether/pullapart.2.Tsunamiwavesdeepatseamovefastandriseonlyafew/hundredsoffeet.3.Asthesekillerwavesentershallowwaters,theirspeedisreduced/raised.4.Mosttsunamidamageiscausedwhenthewavescomeinfrom/movebackouttothesea.waveofcrashingroaringsoundmonitortheearth’smovementsleavethecoastalareasthedeadliesttsunamipreventasimilardisasterinitspathunderwaterTask4：Completethepassagewiththewordsinthebox.ashighasaten-storybuildinglikeanordinarywaveasaresultofitslocationentershallowwatersenormousamountsofenergywholesectionsofcitiesexpandsinalldirectionsThewarningsarefew.Thesignsaresudden.Thegroundshakes.Thetidegoesintoreverse.Agreat______________fillstheair.Andthen…Itstrikes.Waveafter______________,crushingwater.Andwhenitisover,nothingisleft.Atsunami.ThewordinJapanesemeans“harborwave”.Japanhasbeenhitbymanytsunamisinitshistory,________________.Itliesacrosstheedgesoffourtectonicplates.Mostearthquakesareborninsuchplaces.Whentwotectonicplatespushtogether,theearthquakesends________upthroughtheocean.Task4：Completethepassagewiththewordsinthebox.Aseriesofwaves________________.Indeepwater,thesewavestravelfast—upto500milesanhour—butreachaheightofonlyafewfeet.Apassingshipmaynotevennoticethem.Butasthewaves______________andcomeintocontactwiththeoceanfloor,theirspeedisreducedbuttheirheightisraised.Astheymoveontoland,thewavescanrise_________________building.Atsunamiwavedoesn’tbreak______________.Instead,itadvanceslikeawallofwater,crashingovereverythinginitsway,sometimesreachingmorethanakilometerinland.Moredamageiscausedwhenthewavemovesbackouttosea.Itdragseverything_______________andouttosee.Mosttsunamishaveseveralwaves.Theyarrivedbetween10and60minutesafterthefirststrike—justwhensurvivorsthinkthedangerhaspassed._______________everrecordedoccurredinDecemberof2004.AnearthquakeoffthecoastofIndonesiacausedatsunamithatrushedacrosstheIndianOceanandreachedasfarasthecoastofAfrica._________________weredestroyed.Morethan200,000peopledied.Mosthadnowayofbeingwarned.FivethousandmilesawayinHawaii,scientistsatthePacificTsunamiWarningCenter_________________24hoursaday.Theyhopeto___________________fromhappeninginthePacificregion.Iftheydiscoveraquakebigenoughtocauseatsunami,thescientiststrytofindoutwherethewavewillheadandwarnpeopleinitspath.Theiradviceissimple:_____________________andmovetohigherground.Waitfornewsthatthedangerhaspassed.Andbereadytodealwiththedamagethatatsunamileavesbehind.Thewarningsarefew.Thesignsaresudden.Thegroundshakes.Thetidegoesintoreverse.Agreatroaringsound

fillstheair.Andthen…Itstrikes.Waveafterwaveofcrashing,crushingwater.Andwhenitisover,nothingisleft.Atsunami.ThewordinJapanesemeans“harborwave”.Japanhasbeenhitbymanytsunamisinitshistory,asaresultofitslocation.Itliesacrosstheedgesoffourtectonicplates.Mostearthquakesareborninsuchplaces.Whentwotectonicplatespushtogether,theearthquakesendsenormousamountsofenergy

upthroughtheocean.Task5:Readtogether.Aseriesofwavesexpandsinalldirections.Indeepwater,thesewavestravelfast—upto500milesanhour—butreachaheightofonlyafewfeet.Apassingshipmaynotevennoticethem.Butasthewavesentershallowwaters

andcomeintocontactwiththeoceanfloor,theirspeedisreducedbuttheirheightisraised.Astheymoveontoland,thewavescanriseashighasaten-storybuilding.Atsunamiwavedoesn’tbreaklikeanordinarywave.Instead,itadvanceslikeawallofwater,crashingovereverythinginitsway,sometimesreachingmorethanakilometerinland.Moredamageiscausedwhenthewavemovesbackouttosea.Itdragseverythinginitspathunderwaterandouttosee.Mosttsunamishaveseveralwaves.Theyarrivedbetween10and60minutesafterthefirststrike—justwhensurvivors

thinkthedangerhaspassed.Thedeadliesttsunami

everrecordedoccurredinDecemberof2004.AnearthquakeoffthecoastofIndonesiacausedatsunamithatrushedacrosstheIndianOceanandreachedasfarasthecoastofAfrica.Wholesectionsofcities

weredestroyed.Morethan200,000peopledied.Mosthadnowayofbeingwarned.FivethousandmilesawayinHawaii,scientistsatthePacificTsunamiWarningCentermonitortheearth’smovements

24hoursaday.Theyhopetopreventasimilardisaster

fromhappeninginthePacificregion.Iftheydiscoveraquakebigenoughtocauseatsunami,thescientiststrytofindoutwherethewavewillheadandwarnpeopleinitspath.Theiradviceissimple:leavethecoastalareas

andmovetohigherground.Waitfornewsthatthedangerhaspassed.Andbereadytodealwiththedamagethatatsunamileavesbehind.1.Whathaveyoulearntabouttsunamis?2.Whatkindofhelpdoyouthinkpeoplewhohavesufferedfromatsunamineed?Workinpairs.Discussthequestions.AfteryouwatchI’velearntthattheyaredange