using geo map (free app)and excel to finish the assignment.
Please do not take this job if u are not familiar with these features.
The steps are simply on ESS362_LabExcercise_1_2020.pdf. I can provide textbook through email. Please read the background materials for each part. It explains everything.
ONLY CITE TEXTBOOK MATERIAL.
Finish the following questions.
Q1.1-1.8, Q2.1-2.3, Q3.1-3.3
ESS362_LabExcercise_1_2020 1 ESS362LabandExercise1 ForProf.Bergquist Handed out Jan. 13th, 2020 Due Mon Jan. 24th, 2020 Topography&BathymetryProfiles,Depth-AgeRelationshipandPlateMotions LastName:____________________________________________(pleaseprint) FirstName:_____________________________________________ StudentID:__________________________________________ PartI–BathymetryprofilesandGeoMapApp Plottopographicandbathymetric(oceandepth)torelatelarge-scalefeatureson Earth’ssurfacetolithosphericplates,earthquakes,andvolcanoes.Thisexercisealso providesexperiencewithgraphingwithGeoMapAppandconceptsofscale. Abathymetricprofileprovidesa"skylineview"oftheseafloorinwhichhillsare seenasrisesandvalleysasdepressions.Foragraphicalprofiletoillustratethetrue shapeoftheseafloor,aratioof1:1forverticalandhorizontaldistancesmustbethe sameorhavearatioof1:1.Thismeansthatoneunitontheverticalscaleisthesame distanceasoneunitonthehorizontalscale.However,theslopesofoceanfeatures (i.e.,relief)aregenerallysosmallthatitisdifficulttoseeseafloorfeatures.Typical AtlanticOceanbasinfeaturesareonlyafewkilometershigh,whilethebasinitself extendslaterallyforthousandsofkilometers.Iftheprofileweredisplayedwitha1: 1ratioonaregularsheetofpaper,itwouldappearasaflatline. Inordertoillustratethedetailsoftheseafloorrelief,thedepthscaleofanocean profileisverticallyexaggerated(stretched)relativetothehorizontalscale.Vertical exaggerationcausesdistortionintheshapesofthebathymetricfeaturesthatare beingillustratedwiththeamountofdistortionincreasingwiththeamountof exaggeration.Asverticalexaggerationincreasesonaprofile,hillsappeartobe higher,valleysdeeperandtheslopesbetweenthembecomemuchsteeper.Slopes, thatinrealityaregentle,willlooksteep;steepslopeswillappeartobeprecipitous. Forexample,whentheverticalscalehasbeenstretchedfourtimesrelativetothe horizontalscale,wehaveaverticalexaggeration(VE)of4. Theverticalexaggeration(VE)associatedwithageneralprofileisfoundbydividing thehorizontalscalebytheverticalscaleaccordingto: VE=HorizontalScale/VerticalScale Example:VE=(1”=100ft)/(l”=25ft)=4 2 PROFILINGEARTH’SSURFACEUSINGGEOMAPAPP PURPOSE • Torelatelarge-scalefeaturesonEarth’ssurfacetolithosphericplates, earthquakes,andvolcanoes. • TointroduceGeoMapApp,aneasy-to-usemappingprogramfocusedon marinegeologyandgeophysics. OVERVIEW First,followthedirectionsgivenbelowtodrawacrosssectionshowingelevation alongtheline(B-B’)usingGeoMapApp.Afterprintingoutyourcrosssection,add thecharacteristicsspecifiedin(1-5). INSTRUCTIONS DownloadGeoMapAppontoyourcomputerorlaptop.Goto http://www.geomapapp.org/index.htmandfollowtheinstructionsfor downloading. Afterdownloadingtheprogram,double-clickontheGeoMapApp.jaricontorunthe program.ChoosetheMercatormap. InsideGeoMapApp,clickontheDistance/Profiletoolatthetopofthescreen: B B’ 3 YoumayneedtopatientlywaitwhileGeoMapAppopenstheprofilingtool.When theprogramisready,refertotheworldmappicturedinthisexercise.Todrawthe B-B’lineinGeoMapApp,placeyourcursorintheappropriatelocationonthePacific Plate.ClickonthemouseasyoudragthecursoroverjustnorthofMadagascar. Whenyoufirstdothis,thelinemightbedrawnasagreatcircle.Intheprofiletool, clicktheboxspecifyingthatyouwouldliketodrawthecrosssectionalonga straightline: Next,savetheprofiletoyourcomputerandthenprintitout. Usingapencil,addthefollowingcharacteristicstoyourtopographicprofile.For someofthese,youwillneedtorefertooutsidesourcessuchasyourtextbook.For others,youmaydiscovertoolsordatabaseswithinGeoMapApptohelpyou. Profile1Questions: ★Q1.1:Identifyandlabelthepositionsofthefollowingfeaturesonthecross- section: a. Plateboundariesandtheirtypes(e.g.,labeltheEastPacificRiseand indicatethatitisamid-oceanridge) b. Lithosphericplatesandtheirnames c. Continentalmarginsandtheirtypes(passiveoractive) ★Q1.2:PutaseriesofX’swithinthecross-sectiontorepresentzoneswhere significantearthquakeactivitymightbeexpectedtooccur.BesuretoplacetheX’s attheappropriatedepths. ★Q1.3:Put∆‘sonthesurfaceofthecross-sectiontoillustratewhereyouwould expectvolcanicactivitytooccur. AtlanticOceanBasin NowproduceabathymetricprofileacrosstheAtlanticfromN.America (~75°W,40°N)toN.Africa(~14°W,20°N).Trytoincludeonlyalittlebitoftheland abovesealevel. Profile2Questions: ★Q1.4:Onthegraph,labelthefollowingfeaturesoftheoceanbasin:continental slope,abyssalplain,mid-Atlanticridge. 4 ★Q1.5:Whatistheapproximateoceandepthatthemid-Atlanticridgeandthe reliefoftheridge(differenceindepths,orelevations,betweenthetopofthe ridgeandtheadjacent,relativelyflatoceanbottom)? Oceandepthatmid-Atlanticridge__________ Relief(differenceinoceandepthbetweentheridgeandtheabyssal plain)ofthemid-Atlanticridge__________ ★Q1.6:Whatistheapproximateslopeofthewestflankofthemid-AtlanticRidge (measurethedifferenceinoceandepthalongtheprofilebetweenabout2200 kmand3200kmdistanceanddividebythedifferenceindistance,3200-2200or 1000km).Besurethatbothmeasurements,differencesindepth,anddistance, areinthesameunits,eitherkmorm.Theresultingnumberwillbetheslope expressedasaratio.Theslopecanalsobegivenasapercentorasanangle. Approximateslopeofthewestsideofthemid-Atlanticridge__________. LastProfile:MarianaTrenchregion ProduceabathymetricprofileacrosstheMarianaTrenchregionandincludeboth thevolcanicarcridgealongwiththefartherbackremnantarc. ProfileQuestions: ★Q1.7:Onthebathymetricprofile,labelthetrench,theactivevolcanicarc,and theremnantvolcanicarc. ★Q1.8:Undertheprofile,sketchwhatyouthinkishappeninginthecrustandupper mantle(i.e.,whataretheplatesdoinghere?). 5 PartII–AnalyzingtheoceandepthandageadjacenttotheMid- oceanridge. InPartIofthisexercise,weexaminedthedepthoftheAtlanticOceanbasinand observedtheprominentmid-oceanridge(MOR)nearthecenteroftheoceanbasin. TheMORisalsoknowntobeanareaofshallowearthquakeandvolcanicactivity andisinterpretedasaspreadingcenterwherenewoceanlithosphereisformed. Thenewlyformedoceaniccrustanduppermostmantlethenmovesawayfromthe ridgeaspartofplatetectonicprocesses.TheupliftoftheMORisinterpretedtobe duetorisinghotmaterialthatformsthenewoceanlithosphere.Asobservedinthe oceanprofile,theoceandepthincreasesawayfromtheMOR.Thesubsidenceofthe oceaniclithosphereiscausedbycoolingofthelithosphereasitmovesawayfrom theridgeandareaofrisinghotmaterial.Wecanexaminethisprocessusingocean crustageanddepthdata.Inthefigurebelow,theageoftheoceaniccrustforapart oftheNorthAtlanticOceanisshownbythecolors.TheboldlineistheAtlantic OceanprofileusedinPartI.ThenumbersabovetheprofiletotheeastoftheMOR areinterpretedageboundariesinmillionsofyears.Theoceanageinformationis derivedfromradiometricdatingofoceancrustsamplesfromdeepdrilling,datingof indexfossilsinsedimentsoverlyingthenewly-formedcrust,andthepaleomagnetic reversalstimescale. OceancrustagesforaportionoftheNorthAtlanticOcean(from http://www.ngdc.noaa.gov/mgg/image/crustageposter.gif). IntheTableonthenextpage,thefirsttwocolumnsshowdistancefromtheridge andoceandepth.Theoceandepthdataaretheaverageofthedepthsonthetwo 6 sides(westandeastoftheridge)oftheMOR.Usingthedistancescaleonthe OceanAge.pdfimageabove,estimatebyinterpolationtheoceancrustageat100km incrementsoutto1200kmfromtheridgeandrecordtheresultsintheTable.Then, takethesquarerootoftheagedataandrecordtheresultsinthelastcolumn.The firsttwoageandsquarerootofagedatapoints,for0and100kmdistance,have alreadybeenenteredintheTable.YoushouldproduceanExcelplot,oruseother software,toattachtothesepagesforsubmission. PartIIQuestions: ★Q2.1:Plottheoceancrustageanddepthdata.Howdoesthedepthchangewith increasingage? ★Q2.2:Plotthesquarerootofageanddepthdata.Howdoesthedepthchangewith increasingSQRT(age)? ________________________________________________________________________________ Atheoreticalcoolingmodeloftheoceaniclithospherecanbederivedfromthe theoryoftheflowofheatthroughsolids.Thetheoryindicatesthattheoceandepth shouldincreaseawayfromtheridgeapproximatelyfollowingtheequation:Depth= slope•SQRT(age)+y-intercept. Thetheoryisfurtherexplainedbythefollowing: Newlyformedoceaniclithospheremovesawayfromthemid-oceanridgeandcools asitisremovedfromunderlyingsourcesofheat.Coolinghastwoeffects:1) lithospherecontractsandincreasesindensity;2)thedepthofthe 7 lithosphere/asthenosphereboundaryiscontrolledbytemperatureandcooling causesthelithospheretoincreaseinthicknessawayfromthemid-oceanridge. Coolingandcontractionofthelithospherecauseaprogressiveincreaseinthedepth tothetopofthelithosphereawayfromtheridge.Thisisaccompaniedbyadecrease inheatflow. Parsons&Sclater(1977)determinedthenatureofage-depthrelationships ofoceaniclithosphere,andhaveshownthatthedepth,d(metres)isrelatedtoaget (millionyears)by: Thisrelationshiponlyholdsforoceaniclithosphereyoungerthan80Ma.Forolder lithosphere,therelationshipindicatesamoregradualincreaseofdepthwithage. Thisrelationshipexplainstheobservedbathymetryinmostareas.Thus,ifone knowsthedepthoftheseafloor,itispossibletoestimatetheageoftheseafloor.The depthoftheseafloordependsuponitsageratherthandistancefromtheridge. ________________________________________________________________________________ ★Q2.3:Estimatea“bestfit”straightlinethroughthedatapointsintheSQRT(age) vs.Depthgraph(above)usingExcel(lineartrendline).Calculatetheslopeand interceptcoefficientsofthelineandrecordthemhere(theformofthisequationis y=bx+a,whereyisdepth,bistheslope,xisSQRT(age),andaisthey-intercept Depth=______•SQRT(age)+______(Depthisinm,ageisinm.y.;putbinthe1st space,ainthe2nd) TheSQRT(age)vs.depthdatashoulddisplayastraightlinerelationshipthatis consistent(inshapeandvaluesofthecoefficients)withtheoceanlithosphere coolingmodel(andthephysicsofheatconduction),andthusprovidesstrong evidencesupportingtheseafloorspreadingprocessandplatetectonicstheory. 8 PartIII:PlateMotionsUsingHotSpots: TheHawai'i-Emperorchainofseamounts(volcanoesrestingontheoceanfloor) stretchesfromitsactiveendattheBigIslandofHawai'iwestandnorthacrossthe PacificOceanfloortotheAleutiantrenchneartheKamchatkaPeninsula(first figure).Thereareabout110individualvolcanoesintheHawai'i-Emperorchain(see thedatatable),whichisabout6000km(3800miles)longaltogether.TheHawai'i- Emperorchainisdividedintotwosegments,theWNW-trendingHawai'ianchain andtheN-trendingEmperorchain.Thetwochainsmeetataprominentbend, aroundtheunderwaterseamountsDaikakujiandYuryaku. Theactiveend(youngestend)oftheHawai'i-EmperorchainisattheBigIslandof Hawai'iandtheoffshore,stillunderwatervolcanoLoihi.KilaueavolcanoontheBig Islandisactivetoday,andothercentersontheBigIslandandonMauihaveerupted recently.Asoneprogressestowardsthewest-northwest,thevolcanoesofthe Hawai'ianIslandsgetprogressivelyolder(seedatatable).Onceactivevolcano buildingthrougheruptionsoflavaceases,theerosionalforcesoftropical weathering,landslides,rivererosion,andwaveactionovercometheisland,and erodesitdowntosealevel(secondfigure).Theextinctvolcanoevolvestoaflat- toppedmesaringedbycoralreefs,andthentoanatollwithnothingbutthecircular 9 reefshowing.Finallythevolcanosinksbeneaththewaves,andbecomesan underwaterseamount. TheHawai'i-Emperorchainisaclassicexampleofahotspottrack.Thestandard explanationbeginswithahotspotwhosesourceofmagmaisrooteddeepinthe Earth'smantle.Thehotspotmagmasourceisthoughttobefixedinthedeeper mantle,withaslabofoceancrustanduppermostmantle(calledaplate)moving laterallyabovethehotspot.AsthePacificPlatemovesovertheHawai'ianhotspot, magmapunchesupthroughthePacificPlate,creatinganactivevolcano.Plate motioncarriestheactivevolcanoawayfromthemagmasource,thevolcanogoes extinct,andanewvolcanogrowsoverthehotspot.Astheextinctvolcanoiscarried fartherandfartherfromthehotspotsource,thevolcanosinksbeneaththewaves mostlyduetoagingandcoolingoftheoceancrustunderneaththeextinctvolcano; thiscoolingcausessubsidenceoftheoceanfloor. Hotspottracksareveryimportantgeologicfeaturesfordeterminingboththe directionandspeedoftheplateuponwhichtheseamountsrest.Thedirectionof platemotionisgivenbytheorientationofthechainofseamountsandvolcanoes. Usingyour"handsofscience",youcanquicklydeterminethattheplate"moves towardstheoldestvolcano."Ascanbeseeninthefirstfigure,thePacificPlate movedalmostduenorthduring"Emperortime"(from75to42millionyearsago), andthenchangeddirectionabout42millionyearsago(theageofthevolcanoesat thebendinthechain),tomovewest-northwestduring"Hawai'itime"(from42Ma 10 tothepresent).NotethattheazimuthscitedhereassumenorotationofthePacific Plateduringthelast75Ma. Hotspottracksalsogivethespeedofplatemotion,ifthelengthofthechainsof volcanoesandseamounts,andtheagesofthevolcanoesandseamountsareknown (datatable).Platestypicallymoveabout1-10cm/year,whichisequivalentto10- 100km/Ma(kilometerspermillionyears).Thesespeedsareabouttheratesat whichfingernailsgrow,andmayseemratherslowonthehumantimescale,butare veryfastonthegeologicaltimescale.TheEarthis4.55billionyearsold;onemillion yearsisabriefmomentinEarthtime.ThespeedoftheNorthAmericanplate(for example)isfairlytypicalforplates,about6cm/year,whereastheMarianasplateis oneofthefastest(today),movingabout13cm/year. DistancesfromtheactiveKilaueavolcaniccenter(measuredparalleltothe Hawai'i-Emperorchain)andagesofeachvolcanoandseamountaregiveninthe datatable(ClagueandDalrymple1989).Thesedatahavebeencompiledfroma widevarietyofsourcesandresearchers,whichcanintroduceuncertainties.For example,differentgeochronologiclaboratoriesdeterminedtheagesofthevolcanic rocksfromtheseseamounts,anddifferentlabsoftenusedifferentmachines, differentstandards,anddifferentanalyticaltechniques.Evenwiththehighest qualityofwork,theageshaveuncertaintiesthatvaryfromsampletosample. Furthermore,volcanoesdonothaveasingleage;atypicalHawai'ianvolcanobuilds upoverhalfamillionyearsormore.Whoistosaythatthevolcanicrocksdredged upfromtheunderwaterseamountJingu(forexample)arerepresentativeofJingu's eruptivehistory?ItisverydifficulttosampleJingu'solderrocks;theyarecovered bytheyounglavas.Thedatainthetablearenotwithoutproblems,anddatashould notsimplybeacceptedatfacevalue. PartIIIQuestions: ★Q3.1:Firstplotage(x-axis)versusdistancefromKilaueavolcaniccenter(y-axis). Datagiveninfollowingtable.UsingExcelorsomeothergraphingprogram,fitan unconstrainedlinearregressiontotheentireHawai'i-Emperorchainandfindthe "typical"rateofPacificPlatemotionoverthelast65Ma. a. WhataretheunitsofboththerateandtheY-intercept? b. Howwouldyouwritetheequationsusingcentimetersandyearsfor units? ★Q3.2:Forthesecondpartoftheirexercise,fitunconstrainedregressions(donot forcealinearfitthroughzero)toboththeHawai'ichainandtheEmperorchain separately. a. HasthePacificPlatespeduporsloweddownoverthelast65Ma? b. Achangeinspeedfromtheolderpartofthechaintotheyoungerpartof thechainseemsreasonablefromthedata.Mustachangeinspeed accompanyachangeindirection? 11 c. ApproximatelywhatdirectiondidthePacificplatemoveolderthan42 millionyearsago?Youngerthan42millionyearsago? volcano age age) uncertainty)) distance distance) uncertainty) name (Ma) (±)Ma) (km) (±)km) Kilauea 0.2 0.2 0 1.5 Mauna.Kea 0.38 0.05 54 1.8 Kohala 0.43 0.02 100 2 East.Maui 0.75 0.04 182 2.5 Kahoolawe 1.03 0.18 185 2.5 West.Maui 1.32 0.04 221 2.7 Lanai 1.28 0.04 226 2.7 East.Molokai 1.76 0.07 256 2.9 West.Molokai 1.9 0.06 280 3 Koolau 2.6 0.1 339 3.3 Waianae 3.7 0.1 374 3.5 Kauai 5.1 0.2 519 4.2 Niihau 4.89 0.11 565 4.5 Nihoa 7.2 0.3 780 5.6 unnamed.1 9.6 0.8 913 6.3 Necker 10.3 0.4 1058 7.1 La.Perouse 12 0.4 1209 7.9 Brooks.Bank 13 0.6 1256 8.2 Gardner 12.3 1 1435 9.1 Laysan 19.9 0.3 1818 11.1 Northampton 26.6 2.7 1841 11.3 Pearl.&.Hermes 20.6 0.5 2291 13.6 Midway 27.7 0.6 2432 14.4 unnamed.2 28 0.4 2600 15.3 unnamed.3 27.4 0.5 2825 16.5 Colahan 38.6 0.3 3128 18.1 Abbott 38.7 0.9 3280 18.9 Daikakuji 42.4 2.3 3493 20 Yuryaku 43.4 1.6 3520 20.1 Kimmei 39.9 1.2 3668 20.9 Koko 48.1 0.8 3758 21.4 Ojin 55.2 0.7 4102 23.2 Jingu 55.4 0.9 4175 23.6 Nintoku 56.2 0.6 4452 25.1 Suiko.1 59.6 0.6 4794 26.9 Suiko.2 64.7 1.1 4860 27.2 12 YellowstoneHotSpot: Hotspotsmayoccuroncontinentallithosphereaswellasoceaniclithosphere.For example,YellowstoneNationalParkisahugevolcaniccaldera(collapsedsummitof avolcaniccone)thatwebelievehadaculminatingeruptionsome600,000years ago.Thisisonlythelatestinaseriesofmajorcaldera-formingeruptionsthathave traveledoccurredduringthelast16millionyears.Infact,wecantrackthe movementofthisstill-activevolcanichotspotasithasshiftedfromOregonthrough Idaho(creatingitsSnakeRiverPlainVolcanicProvince)intoWyoming.Seemap below.Becausethehotspotisstationary,wecanapplythesamemethodasbefore inordertocalculatethisrate. ★Q.3.3: a.Fromthefigureabove(andthescalegiveorGoogleEarth),estimatethedirection andspeedoftheNorthAmericanplateovertheYellowstonehotspot(plotyourdata andfitthedatausinganunconstrainedlinearfitlikeintheHawaiianexample– showyourfigure). b.HowdoesyourestimateofspeedcomparewiththePacificPlate?Whydoyou thinktheyaredifferent?