MEA 200 Exam #1 NCSU Questions And Answers Rated A+

big bang - -still energy left from explosion -discovered in 1960s -assumes earth came from material -Kant created most pop model of formation (planet accretion) nebula - beginning form of planets many bump into others and combine earths composition - -more dense material in center -heterogeneous (bc heat and dense elements melt and flow) -accretion -compression -radioactive decay 3 layers of earth - -based on composition -core, mantle, crust -metallic core sank to center lithosphere - -rigid outer covering -crust and top of mantle -tectonic plates asthenosphere - -weak solid that flows -bottom of mantle -tectonic plates float on itmoon - -likely broke off of earth -small planet hit earth and tilted it -chunk (moon) broke off Alfred Wegener - 1915- continental drift -200 mill years ago: pangea Wegener's evidence - 1-puzzle piece fit of continents 2- similar mtn ranges/fossils across oceans ( palm fossils antarctica/tropics) 3- large glacier boulders in tropics 4- same species btw continents Alexander Du Toit - "our Wandering Continents" -developed Wegener's arguments Benioff zones - data from 1920-60 -plotting earthquakes and volcanoes -center of ocean/tracing continents -magnetic reversal patterns on seafloor Harry Hess - -sea floor spreading -echo-sounding surveys during WWII in Pacific -idea: new crust produced at mid ocean ridges and consumed in deep sea -magnetic patterns backed up Wilson cycle - -John Tuzo Wilson -plate tectonics model -refers to once sequence of evernts leading to: formation, growth/expansion, destruction?contraction, elimination of basinsforming ocean basins 1- embryonic ocean - -uplift and expansion -ex: east africa rift valleys forming ocean basins 2- juvenile ocean - -subsidence and spreading -no subduction -constructive plate margin formation -ocean crust development in rift -ex: red sea forming ocean basins 3- mature ocean - -spreading -little subduction -active mid-ocean ridge -Palaeomagnetic stripes -ex: Atlantic forming ocean basins 4- declining ocean - -spreading/shrinking -active spreading axes -subduction with marginal trenches -ocean ridge not central -fast due to slab pull -ex: Pacific