EARTHQUAKES
Objective:Todefineanddiscussearthquakesanditseffects
Earthquakesareamajorcatastropheandcanbeabigthreattohumanlives.Tounderstand earthquakesyoumusthaveacleardefinition,knowitsmechanisms,beabletorecognizethesize anddynamicsandunderstanditseffects:
I.DefinitionofEarthquake
a.Earthquake
bTsunamis
c.Landslides
d.Volcanoes
II.Mechanism
aFaults
b.SeismicWaves
c.Aftershocks...showmorecontent...
Theslippingfaultthencreatesseismicwavesinthesurroundingrock.Seismicwavescreatethe soundwavesintheair.Italsocarriesenergyawayfromthefault,firsttonearbyrock.Inhoursto followorevendaysmanysmallearthquakesoccurThesearereferredtoasaftershocksAftershocks arearesultofrocksnearthefaultadjustingtoaccommodatethenewstresslevels.
Inordertounderstandthesizeofanearthquakecertainitemsmustbetakenintoconsideration. Strength,classificationofseismicwaves,logarithmandintensityaresomeofthemainareasto focuson.Thestrengthdependsupontheareaofthefaultlengthtimeswidthonwhichtheslip occurs,theamountoftheslipandtheinherentstiffnessofthenearbyrock.Anearthquakeoccurring a100–km(62–mi)faultisaboutonebilliontimesstrongerthanaquakeona100–m(328–ft)fault. SeismicwavesareclassifiedintwoareasP–waves,whichareyourcompressionalwaves,andS–waves,whichareshearwavesThesewavesareusedindetectionandlocationofearthquakes
Severalthousandseismometersareincontinuousoperationworldwide.Thesestationsrecordground motions,detectwavesevenatgreatdistancesfromthefaultaswellasmeasurearrivaltimeofPand Swaves.Logarithmofmoment
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Iwillbediscussingtheneedsofabudgetandwhatsupplieswillbeinthebudgetplan.Thenyou willreadsomeabouttheshelterprovided,populationofthecommunity,anddamagescausedby earthquakesTherewillbeinformationaboutthepolicyandprocedurestofollowforanearthquake andwhatchallengeswehavetoface.Theconclusionwillbecompletedinthenextphase.|
EarthquakePreparedness Budget
Therearethreemajorconsequencesofanearthquake:injurytoemployees,customersandvisitors; damagetoproperty,theinfrastructureofthearea,andlifelines;anddisruptionofbusiness operations(Crook,1999).Thisis...showmorecontent...
DamagesCausedbyEarthquakes
PastRecordsofEarthquakeDamagesTherearemanydifferenttypesofdamagesthatcanbecaused byearthquakes.Peoplelosetheirhomes,businessesaredestroyed,andmuchmore.Statisticsshows theeconomicdamagecausedbyearthquakesbetween1900'sandpresenthereintheUnitedStates are41.04billionsofdollars(EconomicDamageCausedByEarthquakesByCountyUpTo2012, 2012)Betweentheyears2006to2012therewas7,340earthquakeswithamagnitudeof40to49 (EarthquakesWorldwideByRichterScaleGradationUpTo2012,2012).Manylivesaretakenfrom theeffectsofanearthquake.
OtherDepartmentInvolvementOtherorganizationspulltogetherandhelpwiththedisastersacross theworld.Hereisalistofafeworganizationsandtheservicestheyoffer:AmericanRedCross| Fixed/mobilefeedingstations,shelter,cleaningsupplies,comfortkits,firstaid,blood,food, clothing,emergencytransportationandmuchmore.|FriendsDisasterService|Providesclean–up andrebuildingassistancetotheelderly,disabled,lowincome,oruninsuredsurvivorsofdisasters.| SalvationArmy|Massandmobilefeeding,temporaryshelter,medicalassistance,anddistribution ofdonatedgoodssuchasfood,clothes,andhouseholditems.|VolunteersofAmerica|Making vehiclesavailablefortransportingvictimsandsuppliestodesignate
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WhatisanEarthquake?
AnEarthquakeistheshakingoftheearth'ssurfacecausedbyrapidmovementoftheearth'srocky outerlayer.Thesuddenshakingofthegroundthatoccurswhenmassesofrockchangeposition belowtheEarth'ssurfaceiscalledanearthquakeTheshiftingmassessendoutshockwavesthat maybepowerfulenoughtoalterthesurfaceoftheEarth,thrustingupcliffsandopeninggreat cracksintheground.
Earthquakes,calledtemblorsbyscientists,occuralmostcontinuouslyFortunately,mostofthemcan bedetectedonlybysensitiveinstrumentscalledseismographs.Othersarefeltassmalltremors. Someoftherest,however,causemajorcatastrophes.They
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AlthoughitiscertainthatviolentEarthtremorsinthemselvesaredestructive,thereareoftenother kindsofEarthmovementsthataretriggeredbyearthquakeshockwaves.Thus,theviolentshaking thataccompaniesmanyearthquakesoftencausesrockslides,snowavalanches,andlandslidesIn someareastheseeventsarefrequentlymoredevastatingthantheEarthtremoritself.
Floodsandfiresarealsocausedbyearthquakes.Floodsarisefromtsunamisalongcoastlines,from large–scaleseichesinenclosedbodiesofwatersuchaslakesandcanals,andfromthefailureof dams.Fireproducedthegreatestpropertylossfollowingthe1906SanFranciscoearthquake,when 521blocksinthecitycenterburneduncontrollablyforthreedaysFirealsofollowedthe1923 Tokyoearthquake,causingmuchdamageandhardshipforthecitizens.
Causes
MostoftheworstearthquakesareassociatedwithchangesintheshapeoftheEarth'soutermost shell,particularlythecrust.Thesesocalledtectonicearthquakesaregeneratedbytherapidrelease ofstrainenergythatisstoredwithintherocksofthecrust,whichoncontinentsisabout22miles thickAsmallproportionofearthquakesareassociatedwithhumanactivityDynamiteoratomic explosions,forexample,cansometimescausemildquakes.Theinjectionofliquidwastesdeepinto theEarthandthepressures
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Earthquakes:ANaturalHazard IntroductiontoEarthquakes
Anearthquakeisanaturalhazardthatcausesdeathanddestruction.Earthquakesmainlyoccuron theboundaryoftwotectonicplates,knownasfaultlines,astheplatesmoveagainsteachotherand getstuckwhichcreatesastrainandresultsinrocksbreakingThisreleasesenergyintothe lithosphere(crustanduppermantle)causingshakingoftheearth'ssurface.Theenergyreleasedis calledseismicwavesandthesearemeasuredonalogarithmicscalecalledtheRichterscale.
EffectsofEarthquakes(humanorphysical)
Groundshakingandunstablebuildingsaresomeoftheshort–termphysicaleffectsthatarecaused byseismicwavesFirescanbecreatedwhenashowmorecontent
Aswellasthattheyshouldtrytofindaplacethatissafe;suppliessuchasbottledwaterandcanned foodshouldbeeasytoreach.Communicationsystemscanbeaffectedsomostwillsetupplansfor contactingfriendsandfamily.
Immediatelyafteranearthquakelootingoftenhappensasmanywillbewithoutsupplieshowever somepeoplereactverydifferentlyandtrytohelpasmanypeopleastheycanCountriesaroundthe worldwillsendmoneyandfood;somemayevensendvolunteerstohelpandadministerfirstaid. Therubblewillbeclearedtofreethepeopletrapped.Buildingsbeingmadesafeisanotherwaythey wouldhelpbutdependingonthecountry'sfundingitdoesn'talwayshappenimmediatelyTourism maydecreaseasthetouristscouldbescaredofanotherearthquakeoraftershockoccurring. Long–termresponseswouldbethingslikebuildingrestorationbecauseaftershocksarenotunusual. Beforeorafterrestorationbeginsaninvestigationmayberequiredtofigureoutwhythebuilding collapsedandiftherewereanyfaultsinconstruction.Theeconomywillbenegativelyaffectedas rebuildingiscostlyandnormalworkispreventedfromhappeningforquiteawhileWhilstthereare investmentsmadeforrebuildingandaidissentintheimmediateaftermath,familiesmaystruggle withreducedincomesandreplacementofclothingandhouseholditems.
CaseStudien Japan
TheTōhokuearthquakeisaprimeexampleofanearthquakecreatingatsunamiWithamagnitude
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TheJanuary12,2010HaitiEarthquakecausedanenormousdestructionintheCaribbeannation. Hospitalsandgovernmentbuildingscollapsedalongwithanunbelievableamountofhomes.Tensof thousandsofpeoplewerekilled,andmanymorewerewounded.Thedisasteraddedmoremiseryto peoplealreadystrugglingtogetbywitheverydaylife.Haitiisoneofthepoorestnationsinthe worldTheJanuary12quakedemolishedalmosteverymajorbuildinginPort–au–Prince,Haiti's capital.About5,000schoolsinthecityweredestroyedordamaged.ThroughoutHaiti,morethan 220,000peoplewerekilled,andmorethan1millionwerelefthomeless.Afewdaysafterthequake, thenumberofsurvivorsstoodat121ashopesoffindingmorebecameshowmorecontent
ThemostrecentcyclonestohittheislandbeforetheearthquakewereTropicalStormFayand HurricanesGustav,HannaandIke,allinthesummerof2008,causingnearly800deaths.[27]
Geology USGSintensitymap
MapshowingregionaltectonicsettingoftheEnriquillo–PlantainGardenfaultzone
Tinydotsofwhiteagainsttheplant–coveredlandscape(redinthisimage)arepossiblelandslides,a commonoccurrenceinmountainousterrainafterlargeearthquakes.TheEnriquillo–PlantainGarden faultzonerunsalongthetwolinearvalleysatthetopoftheimageThemagnitude7.0Mw earthquakeoccurredinland, ...Getmorecontent...
Earthquakes
Earthquakes,oneofthemostdestructivenaturalphenomena,consistofrapidvibrationsofrocknear theearth'ssurface.Becauseoftheirunpredictableoccurrenceandenormouscapacityofdestruction, theyhavebroughtfeartomankindsinceancienttimesAsingleshockusuallylastsnomorethana fewseconds,butaseriesofsmallerquakesmaylastforaslongasfiveminutes.Thequakefelton thesurfaceisalwaystheresult,notthecauseofsomeundergroundgeologicprocess,andinmany casesthedamagedoneisimmenseTheGreekwordforshaking,and(whenappliedtotheearth) earthquake,isseismos.Therefore,thescienceofearthquakesiscalledseismology(WorldBook Dictionaryshowmorecontent
Fires,landslides,tsunami,fallingrock,damagedbuildings,anddamagedgaslinesarejustafew resultsofsecondaryshocks.Theseconditionsreekhavoconearthquakecorruptedareas,andin 1934,Bihar–NepalwitnessedthisfirsthandDuringalandslide,"anobserverreportedthat hiscarsanktotheaxles".In1946offthecoastoftheAleutians,thebaseofalighthouseended up45feetbelowsealevelafteratsunamiwaveover100feetcrashedonshore(Watkins,Bottino, Morisawa51,53–54).
Anearthquakeisanaturaloccurrence;aphenomenajustlikerainTheyhaveoccurredforbillions ofyearsanddescriptionsasoldasrecordedhistoryshowstheireffectsonpeople'slives.Long beforescientificexplanationsmankindcreatedfolkloretoexplainthem.Wehavecomealongway forspinningyarnsaroundthecampfire,butthereisstillnowaytopreventearthquakesAllinallit doesn'thurttolearnasmuchasonecan,butjustliketaxesandpokemonearthquakesaresomething wehavetolivewith.
EARTHQUAKEREFERENCEFILESEarthquake,shakingoftheearth'ssurfacecausedbyrapid movementoftheearth'srockyouterlayerEarthquakesoccurwhenenergystoredwithintheearth, usuallyintheformofstraininrocks,suddenlyreleases.Thisenergyistransmittedtothesurfaceof the
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Wehavetoknowwhatearthquakesareinorderforustobepreparedagainstthem.Earthquakesare tremorsthatmovetheearth.Theycancreatealotofdamage.Earthquakeshavehappenedaround theworld.Whatcausesearthquakestohappen?Howdoweprotectourselvesagainstthepowerful earthquakes?Earthquakescancausealotofdamagetohomesandplacessoitisimportanttoknow whereithashappenedAlsowhatcausesthemandhowdoweprotectourselvesagainstearthquakes Tobeginwithearthquakescanhappenaroundtheworld.A6.3earthquakedestroyedhistoric buildingsinItaly.OnJanuary12,2010apowerful7.0...showmorecontent...
It'simportanttoknowthatearthquakeshappenaroundtheworldsopeoplearepreparedfor earthquakesanytimeanywheretheyare.Wealsohavetoknowwhatearthquakesaretobeprepared. Anotherexampleiswhatearthquakesare.Earthquakesarecalledtremorsandcanbetremendously destructive.Anearthquakesmagnitudeisameasuredvalueofitssizeandisthesamenomatter where.Thereisnosuchthingasearthquakeweather.Anearthquakeiswhathappenswhentwo blocksoftheearthsuddenlyslippastoneanotherThesurfacewheretheyslipiscalledthefaultor faultplane."Anearthquakeiscausedbyasuddenslipinthefault."saidatanarticlewithearthquake factsatearthquake.usg.com.Itsimportanttoknowwhatearthquakesarecausedbysowecan understandthembetter.thatwaywecanprotectourselvesagainstearthquakes.Aswellaslearning howtoprotectyourselfagainstearthquakes.Animportantthingistoduckandcover.Duringan earthquake,ifyouareindoors,itisveryimportanttostaycalmandtakecoverunderaheavyobject Ifyouareoutdoors,stayasfarawayfrombuildingsaspossible.Getawayfromshelvesorother areaswhereobjectsmayfallifinacrowdedstoreorpublicarea.Donotrunforthedoor.Crouch andcoveryourheadandneckwithyourhandsandarms"Trytogetintoanopenarea"Getting intoanopenareanot
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Earthquakes
Throughouthistory,manhasmademanyadvancements.Theseadvancementshavebeenmadeto makelifeeasier.Theonethingmancan'tdoistocontrolMotherNature.MotherNaturecancause manythingssuchasearthquakes
Thecausesofearthquakeshavebeentheorizedinmanyways.Accordingtothebook PredictingEarthquakesbyGregoryVogt,theGreeks,"blamedtheearthquakesonPoseidon,godof thesea"(25).TheHindubelievedthat"theearthwasaplatformthatrestedonthebackofeightgreat elephants.Whenoneoftheelephantsgrewweary,itloweredandshookitsheadcausingtheground abovetotremble"(Vogt25).MargaretPoynterwrites"manyprimitivepeoplethoughtthattheearth resteduponthebackofsome...showmorecontent...
Hemadetests,drewaworldmap,andrecreatedearthquakesonlytofindthatrocksarebeing overstressedatthefaults."Afaultistheplacewheretwoplatesmeetandarerubbedagainsteach other"(GroilerElectronicPublishing, Inc.).Thebook,PredictingEarthquakes,theauthorpointsout"Therearegenerallythreekindsof faults:normal,reverse,andstrike–slip.Bycarefulobservationandmeasurement,geologists,acting likedetectives,cantellhowmuchafaultmoved,whichpartwentup,whichpartwentdown,and whichwaythefaultmoved"(Vogt26)."Whenoneoftheplatesslipunderthegreatamountofstress atthefault,anearthquakeoccurs.Theshakingwefeelarethepassingoflongwaves"(Putnam443). "TheL–waves(longwaves)travelatslowervelocitiesthattheprimaryandsecondarywavesThese wavesmakethelargestsquigglesonaseismographbuttheireffectdiminishesrapidlywithdistance. TheL–wavesarelimitedtothecrust"(Putnam443).
Oneofthetwokindsofwavesare"Primarywavesareakintosoundwaves,andthusproduce alternatecompressionandrarefactioninthemediumthroughwhichtheytravelmuchlikethewaves thatspreadoutthroughtheairinalldirectionsfromatuningfork"(Putnam444).
Thesecondofthetwokindsofwavesare"Secondarywaves,theparticlesintherockthroughwhich thewaveistravelingvibrateatrightangles,ortransversely,tothedirectionof
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OnEarthquakes
Anearthquakeisashakingortremblingofthecrustoftheearthcausedbyundergroundvolcanic actionorbythebreakingandshiftingofrockbeneaththesurface.Thevolcanicactionandshifting rockscreatestrainwhichcontinuestobuildtoasuddenreleaseofpressureresultinginashock wave.Thevibrationsproducedinthecrustcanvaryfrombarelynoticeabletoenormously destructive.Shockwavescanbeclassifiedintotwobroadcategories.Wavesthatsendparticles oscillatingbackandforthinthesamedirectionasthewavesaretravelingarecalledprimary Primarywaves,sometimescalledcompressionalwaves,travelthroughtheearthbeneaththecrust.
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ThemodernseismographwasinventedearlythiscenturybyaRussianseismologist,PrinceBoris Golitzyn.Thisdevicemadepossiblethemoderneraofearthquakeresearch.
Althoughearthquakeshaveoccurredandaffectedmankindforaslongashumanshavebeenaround, historicalrecordsareeitherlackingorconsideredunreliablebeforethemiddleofthe18thcentury. However,somerecordsdoexistanddatemajorearthquakeeventsbackto425BCwhenone occurredoffthecoastofGreeceresultinginanislandnamedEuboea.AnotheroccurredinAsia MinoraboutAD17andanotherleveledmuchoftheRomancityofPompeiiinAD63Duringthe MiddleAges,severeearthquakesstruckEngland,in1318;Naples,Italy,in1456;andLisbon, Portugal,in1531.
Casualtiesfrommajorearthquakeshaveresultedinthegreatestdisastersinhistory.Theworst occurredin1556intheShannxi(Shensi)ProvinceinChinaandkilledanestimated800,000people. Duringthe18thcentury,theJapanesecityofEdo(siteofmoderndayTokyo)wasstruckandkilled 200,000.EarthquakesinSicilyin1693andLisbonin1755eachkilledabout60,000people.In 1797,approximately40,000diedwhenQuito,Ecuadorwasstruck
Historically,themostpowerfulearthquakestostrikeNorthAmericaoccurredin1811and1812in southeasternMissouriHowever,themostfamousearthquaketostrikeinNorthAmerica
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