7Branches of Earth Science Because one person cannot keep up with the development in all areas of earth science, most earth scientists today specialize in one of the following four major areas of study:GeologyOceanographyMeteorologyAstronomy
8GeologyGeology – The study of the origin, history and structure of the solid earth and the processes that shape the earthExplore the earth’s crust in search of new deposits of coal, oil, gas, and other valuable resources.Study the forces within the earth in order to better understand earthquakes and volcanic eruptions.Study fossils to learn more about the earth’s past
9Branches of Earth science: Study of the earth, its history, its changes and its place in the universeBranches of Earth science:Geology- study of the earth’s origin, history and structurephysical- materials that make up earth and the processes that shape earth’s surfacehistorical-earth’s history
10OceanographyOceanography – The study of the earth’s oceans. Oceans cover nearly three-fourth’s of the earth’s surface.Work on research ships equipped with special instruments to study the sea.Study waves, tides, and ocean currents.Explore the ocean floor for clues to the earth’s history and to locate mineral deposits.Study marine plant and animal life
11Meteorology Meteorology - The study of the earth’s atmosphere. Meteorologists use satellites, radar, and other modern technology.Study the variations in atmospheric conditions that produce weather.Observe weather, measuring wind speed, temperature and rainfall. Information is used to make weather mapsUse weather maps, satellite images, and computer data to make weather forecasts
12Astronomy Astronomy – The study of the universe beyond the earth. One of the oldest branches of earth science. Ancient Babylonians charted the planets and stars nearly 4000 yrs. ago.Modern astronomers use earth and space based telescopes and other instruments to study the universe.Space probes, such as , Pioneer, Voyager, Galileo, and Ulysses have provided much useful data.
13Meteorology- study of the earth’s atmosphere, weather and climate Oceanography- study of the earth’s oceans, including their physical features, life forms and natural resourcesAstronomy- study of the universeHydrology- study of earth’s water
14Ecology Earth Scientists primarily study the: Geosphere – The solid earthHydrosphere - The earth’s waterAtmosphere – The gases surrounding the earth
15EcologyAnother area of science in which earth science and biology are closely linked is Ecology. “Eco” comes from the Greek word “oikos”meaning house.Ecology – The study of relationships between living things and their environment.Ecosystem means the environment a community of organisms inhabit. The largest ecosystem is called the biosphere.The Biosphere encompasses all life an earth and the physical environment that supports it. It extends from the ocean depths to the atmosphere a few kilometers above the earths surface.
16The Importance of Earth Science Understanding how natural forces shape our environment can help better forecast potential disasters.Studying distant galaxies has led to theories about the origins of this solar system.Clues found by studying rock have provided information about the earth’s past.The earth provides resources that enrich our lives.FuelMetalPaper and Ink
17The Earth is continually changing – sometimes rapidly – like with tornadoes, earthquakes, tsunamis- but, many changes occur so gradually that they go unnoticed in a lifetime.
19Formation of Earth Most researchers conclude that Earth and the other planets formed at essentially the same time. Nebular HypothesisThe solar system evolved from an enormous rotating cloud called the solar nebula.
22Nebular HypothesisEnormous rotating cloud made up mostly of hydrogen and helium, with a small percentage of heavier elements created Solar SystemInner planets were not able to hold the lighter gases - hydrogen and helium. They were pulled toward heavier planets.Earth, Mars and Venus retained heavier gases including water vapor and carbon dioxideOuter planets contain high percentages of water, carbon dioxide, ammonia and methane – Size and frigid temperatures of outer planets provided surface gravity to hold heavier gases.
24Layers Form on EarthDecay of radioactive elements and heat of colliding particles caused interior to meltDenser materials (Fe & Ni) sank to centerLighter, rocky material floated to surface.Sinking and floating still believed to be occurring on a smaller scaleInterior is not made up of uniform materials –layers have different propertiesGaseous materials escaped – atmosphere formed along with the ocean. Composed mainly of gases released from within the planet.
271.2 A View of Earth Earth's Major Spheres 1. Hydrosphere • Ocean is the most prominent feature of the hydrosphere.- Is nearly 71% of Earth's surface- Holds about 97% of Earth's water• Also includes fresh water found in streams, lakes, and glaciers, as well as that found underground
28Earth’s physical environment divided into 4 major spheres Hydrosphere – water portionAll water on EarthWhat makes Earth uniqueWater continually moves – evaporating and then returning as precipitation97% of H2O in Oceans3% is Fresh H2O
301.2 A View of Earth Earth's Major Spheres 2. Atmosphere 3. Biosphere • Thin, tenuous blanket of air• One half lies below 5.6 kilometers (3.5 miles)3. Biosphere• Includes all life• Concentrated near the surface in a zone that extends from the ocean floor upward for several kilometers into the atmosphere
31Atmosphere – gaseous envelope Extends 100km above the Earth90% is within 16km of EarthProvides air we breathProtects from sun’s intense heat and radiationProduce weather and climate
331.2 A View of Earth Earth's Major Spheres 4. Geosphere • Based on compositional differences, it consists of the crust, mantle, and core.- Crust—the thin, rocky outer layer of Earth.- Mantle—the 2890-kilometer-thick layer of Earth located below the crust.- Core—the innermost layer of Earth, located beneath the mantle.
35Geosphere Divided into 3 main parts Core Mantle Crust Dense Made of heavy metalsMantleLess dense than coreThick liquidCrustNot uniform in thicknessThick under the continents, thin under oceansLithosphereRigid outer layerAsthenosphereRocks are partially molten and able to slowly flow
361.2 A View of Earth Plate Tectonics Plate tectonics is the theory that proposes that Earth’s outer shell consists of individual plates that interact in various ways and thereby produce earthquakes, volcanoes, mountains, and Earth’s crust itself.
38Plate Tectonics Lithosphere is broken into plates. Plates slowly and continuously moveMovement is caused by unequal heating and convectionMovements cause: earthquakes, volcanic activity and mountainsDestructive forcesWeathering and erosionConstructive forcesMountain building and volcanism
391.4 Earth System Science What Is a System? A system is any size group of interacting parts that form a complex whole. Closed systems are self contained (e.g., an automobile cooling system). Open systems allow both energy and matter to flow in and out of the system (e.g., a river system).
401.4 Earth System Science Earth as a System Earth is a dynamic body with many separate but highly interacting parts or spheres. Earth system science studies Earth as a system that is composed of numerous parts, or subsystems.
41Earth System Science Studies how Earth’s spheres are interconnected Tries to put together what we know from each branch of science.
42Natural systemsDriven by sources of energy that move matter and/or energy from one place to anotherClosed system – energy moves in and out of the system, but no matter enters or leavesOpen system – energy and matter move in and out of the systemExample – river
431.4 Earth System Science Earth as a System Sources of Energy • Sun—drives external processes such as weather, ocean circulation and erosional processes• Earth’s interior—drives internal processes including volcanoes, earthquakes and mountain building
44Energy comes from 2 sources: SunDrives external processes that occur in the atmosphere, hydrosphere and at Earth’s surfacePowers:WeatherClimateOcean circulationErosional processes
45Earth’s Interior Heat from time Earth formed Generated by decay of radioactive elementsPowers:VolcanoesEarthquakesMountain building
461.4 Earth System Science Earth as a System Consists of a nearly endless array of subsystems (e.g., hydrologic cycle) Humans are part of the Earth system.
471.4 Earth System Science People and the Environment Environment • Surrounds and influences organismsPhysical environment encompasses water, air, soil, and rockThe term environmental is usually reserved for those aspects that focus on the relationships between people and the natural environment.
48Environment Everything that surrounds and influences an organism Can be biological, nonliving and social
491.4 Earth System Science People and the Environment Resources • Include water, soil, minerals, and energy• Two broad categories1. Renewable—can be replenished (e.g., plants, energy from water and wind)2. Nonrenewable—cannot be replenished in the near future (e.g., metals, fuels)
51Resources Include: Water and soil Metallic and nonmetallic minerals Energy
52Renewable Can be replenished over relatively short times Examples: Plants and animals for foodNatural fibers for clothingForest products for lumber and paperEnergy from water, wind and sun
53NonrenewableProcesses that create them are so slow that it takes millions of years for significant deposits to accumulateExamples:Iron, aluminum, copperFossil fuelsOilNatural gasCoalEarth contains limited quantitiesSome can be recycled – aluminum*
541.4 Earth System Science People and the Environment Population • Population of the planet is growing rapidly• Use of minerals/energy has climbed more rapidly than the overall growth of population
611.4 Earth System Science Environmental Problems Local, regional, and global Caused by people and societies• Urban air pollution• Acid rain• Ozone depletion• Global warming Caused by natural hazards• Earthquakes• Landslides
62Environmental Pollution Pollution – The contamination of the environment with waste products or impurities.
63Environmental Problems Humans and nature cause environmental problemsSignificant threats:Air pollutionAcid rainOzone depletionGlobal warmingLoss of fertile soils to erosionDisposal of toxic wastesContamination and depletion of water sources
64Biodegradable – Substances that can be broken down by microorganisms into harmless substances that are little threat to our environment.Some waste products are biodegradable and pose little threat to our environment.
65Nonbiodegradable Waste Some modern waste products cannot be broken down and are a threat to ecosystems.
66Protecting Our Environment Water, Land and Air QualityOzone – Helps protect plant and animal life from the sun’s harmful UV raysCFC’s - Chlorofluorocarbons
70Review – answer in complete sentences to be turned in to me! What are the four major branches of earth science?Describe the work of meteorologists.What is ecology?Give an example of an ecosystem and explain how it is self- supporting.How might the study of earth science contribute to the survival of the biosphere?
71Environmental hazards are natural processes ExamplesEarthquakesLandslidesFloodsHurricanesDrought