HNRS 228 Astrobiology Chapter 4 - Earth - Bennett & ShostakThe Habitability of EarthSlide 3Some Guiding QuestionsTelling Rocks ApartSlide 6The Rock CycleiClicker QuestionSlide 9Slide 10Slide 11Surface Building ProcessesStress and StrainSlide 14Slide 15MountainsVolcanoesTear-Down ProcessesEarthquakesSlide 20Earth’s Interior and How We Know ItEarth’s Inside StoryEarth’s Interior, Then and NowWhat We Learn from SeismometersCrustal RumblingsSlide 26Slide 27Slide 28Slide 29Slide 30Plate TectonicsPlate tectonics, or movement of the plates, is driven by convection within the asthenospherePlate TectonicsFossils across an oceanSlide 35Development of Geologic TimeGeologic Time ScaleEarth’s AtmosphereThe Earth’s atmosphere has changed substantially over timeSlide 40Structure of the AtmosphereCirculation in our atmosphere results from convection and the Earth’s rotationWindsWeather ProducersSlide 45Slide 46Weather ForecastingClimateSlide 49Slide 50Slide 51Slide 52Slide 53Slide 54Slide 55Slide 56Slide 57Slide 58Slide 59OceanographySlide 61Slide 62Slide 63The Earth’s Magnetic FieldA bow-shaped shock wave, where the supersonic solar wind is abruptly slowed to subsonic speeds, marks the outer boundary of the magnetosphereAn increased flow of charged particles from the Sun can overload the Van Allen belts and cascade toward the Earth, producing auroraeSlide 67Energy Sources and the Earth’s atmosphere, oceans, and surfaceThe Greenhouse EffectSlide 70Slide 71Industrial chemicals released into the atmosphere have damaged the ozone layer in the stratosphereSlide 731HNRS 228 AstrobiologyChapter 4 - Earth - Bennett & ShostakLecture Notes for Chapter 49 February & 14 February 2012Dr. H. Geller2The Habitability of EarthGeology and Life (4.1)Reconstructing the History of Earth and Life (4.2)Rocks, radiometric dating, geological record, fossils, geological time scale, Earth’s ageThe Hadean Earth and the Dawn of Life (4.3)Atmosphere, oceans, heavy bombardmentsGeology and Habitability (4.4)Earth’s interior, plate tectonics, magnetosphere3The Habitability of EarthClimate Regulation and Change (4.5)Greenhouse effect, carbon cycle, ice ages, Snowball Earth, long term habitabilityThe Process of Science in Action: Formation of the Moon (4.6)Sister model, capture model, spinoff model4Some Guiding Questions1. What is the greenhouse effect? How does it affect the average temperature of the Earth?2. Is the Earth completely solid inside? How can scientists tell?3. How is it possible for entire continents to move across the face of the Earth?4. How does our planet’s magnetic field protect life on Earth?5. Why is Earth the only planet with an oxygen-rich atmosphere?6. Why are prevailing winds generally from the west over most of North America but generally from the east in Hawaii?7. What are global warming and the “ozone hole”? Why should they concern us?5Telling Rocks ApartHow geologists tell apart different minerals and rockscolor, luster, texturehardness testscratching one against another•diamond is hardestacid testusing weak hydrochloric acid to streak testform a streak across a ceramic tile6Plate tectonics is involved in the formation of the three major categories of rocksIgneous Rock cooled from molten materialSedimentary Rock Layered eroded material formed by the action of wind, water, or iceMetamorphic Rock Rock that has been altered in the solid state by extreme heat and pressure7The Rock Cycle8iClicker QuestionRocks formed from other rocks that are heated and placed under great pressures are calledA igneous rocksB sedimentary rocksC metamorphic rocksD fault rocksE scarp rocks9iClicker QuestionRocks formed from layers of fine material that have been compressed under water are calledA igneous rocksB sedimentary rocksC metamorphic rocksD fault rocksE scarp rocks10iClicker QuestionRocks formed when molten material cools and solidifies are calledA igneous rocksB sedimentary rocksC metamorphic rocksD fault rocksE scarp rocks11iClicker QuestionWhich of the following are not used to identify rocks:A crystalline shapeB acid testC streak testD hardness testE all of the above can be used to identify a rock12Surface Building ProcessesStress“stress is a force that tends to compress, pull apart, or deform”different types of stresscompressive stresstensional stressshear stressStrain“the adjustment to stress”13Stress and Strain14Surface Building ProcessesFoldsbends in layered bedrockAnticline /\Syncline\/15Surface Building ProcessesFaultingformation of a crack caused by relative movement of rock on either side of a fracture16Mountains“elevated parts of the Earth’s crust that rise abruptly above the surrounding surface”Causesfolding, faulting, volcanic activity17Volcanoes“hill or mountain formed by the extrusion of lava or rock fragments from magma below”Different typesshield, cinder cone, composite (composite shown)18Tear-Down ProcessesWeatheringmechanical weatheringchemical weatheringErosionmass movement (mass wasting)running water (floodplain, delta)glacierwind (deflation and abrasion)impact cratering19EarthquakesDefined as “quaking, shaking, vibrating, or upheaval of the ground”Earthquake causeselastic rebound theoryIntensity measureRichter Magnitudenot linear scale20iClicker QuestionWhat is the term used to specifically define a downward fold of rock material?A scarpB erodaC foldD synclineE anticline21Earth’s Interior andHow We Know It22Earth’s Inside StoryEnergy transfer in the mantle similar to that of a pot of boiling water.23Earth’s Interior, Then and Now24What We Learn from SeismometersThe Earth’s inner and outer cores are composed of iron with some nickel and other metals mixed inThe mantle is composed of iron-rich mineralsBoth temperature and pressure steadily increase with depth inside the Earth25Crustal Rumblings26iClicker QuestionWhich of the diagram represents the MANTLE of the Earth?ABCDE None of the above.27iClicker QuestionWhich of the diagrammed sections of the Earth's interior represents the Outer Core?ABCDE None of the above.28iClicker QuestionWhich of the diagrammed sections of the Earth represents the CRUST?ABCDE None of the above.29iClicker QuestionEnergy transport from one region to another by the movement of material as in the mantle of the Earth is