Chapter 2Chapter 2

World Geography:World Geography:

Looking at the EarthLooking at the Earth

Section 1Section 1

• Planet EarthPlanet Earth

View of earth from spaceChapter Chapter

Focus Focus IntroductiIntroductionon

Earth Viewed From Outer Earth Viewed From Outer SpaceSpace• The Solar SystemThe Solar System

– Made up of sun and all that revolves around Made up of sun and all that revolves around itit

– Earth has an atmosphereEarth has an atmosphere•The air that surrounds the earthThe air that surrounds the earth

• Earth’s MeasurementsEarth’s Measurements– About 93 million miles from the sunAbout 93 million miles from the sun– Diameter of Earth at equator is about 8,00 Diameter of Earth at equator is about 8,00

milesmiles

Earth Viewed From Outer Earth Viewed From Outer Space (Con’t)Space (Con’t)

• Water, Land and AirWater, Land and Air– Earth is roughly 70% waterEarth is roughly 70% water

•Oceans, Lakes, Rivers make up the Oceans, Lakes, Rivers make up the HydrosphereHydrosphere

– Earth is roughly 30% landEarth is roughly 30% land•Earth surface and crust is called the Earth surface and crust is called the

LithosphereLithosphere

– All organisms live in the BiosphereAll organisms live in the Biosphere

Earth’s SurfaceEarth’s Surface

• Inside the EarthInside the Earth– Composed of three layersComposed of three layers

•The CoreThe Core– Inner and Outer core in the center of the EarthInner and Outer core in the center of the Earth

•The MantleThe Mantle– Thick layer of melting materialThick layer of melting material– Material from Volcano eruptionsMaterial from Volcano eruptions

•The CrustThe Crust– Thinnest of the threeThinnest of the three

Only 3-30 miles deepOnly 3-30 miles deep– Planetlike rock that floats on the mantlePlanetlike rock that floats on the mantle

Chart Chart SupplemenSupplement 1.2t 1.2

Earth’s Surface (Con’t)Earth’s Surface (Con’t)• Internal ForcesInternal Forces

– Plates move only roughly 4 inches a yearPlates move only roughly 4 inches a year– When plates pull apart, melted rock rises upWhen plates pull apart, melted rock rises up

• HawaiiHawaii– Shaking or sudden movements in plates are Shaking or sudden movements in plates are

earthquakesearthquakes– When plates collide, the plates bend, fold, or When plates collide, the plates bend, fold, or

crack (fault lines)crack (fault lines)– Underwater, when earthquake happens, Underwater, when earthquake happens,

tsunamis can occurtsunamis can occur• Tsunamis are large waves that can be as fast as 400 Tsunamis are large waves that can be as fast as 400

miles/hr. and up to 100 ft.tallmiles/hr. and up to 100 ft.tall– Pacific PlatePacific Plate

• So active with earthquakes and volcanoes, it is called So active with earthquakes and volcanoes, it is called the the Ring of FireRing of Fire

Map Map SupplemenSupplement 1.1t 1.1

Map Map SupplemenSupplement 1.1t 1.1

External ForcesExternal Forces

• WeatheringWeathering– Breaking down of rocksBreaking down of rocks– Two kinds:Two kinds:

•Chemical weatheringChemical weathering– Water dissolves chemicals in rocks, causing Water dissolves chemicals in rocks, causing

disintegration or break apartdisintegration or break apart

•Physical weatheringPhysical weathering– Breaks rocks into large piecesBreaks rocks into large pieces

External Forces (Con’t)External Forces (Con’t)• ErosionErosion

– Wearing away of the earth’s surface by Wearing away of the earth’s surface by wind, water and glacierswind, water and glaciers

– WindWind•Movement of dust, sand and soil from one Movement of dust, sand and soil from one

place to anotherplace to another– Plants help avoid wind erosionPlants help avoid wind erosion

– WaterWater•Water flows, which cuts the land, wearing Water flows, which cuts the land, wearing

away the soil and rockaway the soil and rock•Ex.Ex.

– Grand CanyonGrand Canyon

External Forces (Con’t)External Forces (Con’t)• Erosion (Con’t)Erosion (Con’t)

– GlaciersGlaciers•Large bodies of ice, move across the surface Large bodies of ice, move across the surface

of the earthof the earth•Similar to water flow erosion, however with Similar to water flow erosion, however with

even greater magnitudeeven greater magnitude•Two types:Two types:

– Glacier SheetGlacier Sheet Large sheets… Greenland and AntarcticaLarge sheets… Greenland and Antarctica

– Mountain GlacierMountain Glacier Snow on mountain top turns to ice and begins Snow on mountain top turns to ice and begins

moving down by gravitymoving down by gravity

Section 2Section 2

• Earth’s FeaturesEarth’s Features

LandformsLandforms

• ContinentsContinents– 7 Continents7 Continents

•Map of ContinentsMap of Continents

• IsthmusIsthmus– Connects two large landmassesConnects two large landmasses– Isthmus of Panama connects North and South Isthmus of Panama connects North and South

AmericaAmerica

•Europe and Asia separated by the Ural Europe and Asia separated by the Ural MountainsMountains

Landforms (Con’t)Landforms (Con’t)• Major LandformsMajor Landforms

– MountainsMountains•Have steep slopes with some kind of peak or Have steep slopes with some kind of peak or

summitsummit

– HillsHills•More rounded and lower than mountainsMore rounded and lower than mountains

– PlateauPlateau•Higher than surrounding land and has one Higher than surrounding land and has one

steep side, called a cliffsteep side, called a cliff

– PlainsPlains•Flat or gently rolling landsFlat or gently rolling lands

Chart Chart SupplemenSupplement 2.1t 2.1

Other LandformsOther Landforms• ValleyValley

– Lowland between to steep sidesLowland between to steep sides

• PeninsulaPeninsula– Land surrounded by water on three sidesLand surrounded by water on three sides

• IslandIsland– Land completely surrounded by waterLand completely surrounded by water

• ArchipelagoArchipelago– Closely scattered islandsClosely scattered islands

• Continental ShelfContinental Shelf– Underwater extension of a continentUnderwater extension of a continent

Water FeaturesWater Features

• Oceans and SeasOceans and Seas– 70% Earth is water and it is mainly salt 70% Earth is water and it is mainly salt

waterwater– Four major oceansFour major oceans

•PacificPacific•AtlanticAtlantic•ArcticArctic• IndianIndian

– Seas, Gulfs, BaysSeas, Gulfs, Bays•Smaller forms of salt waterSmaller forms of salt water

Water Features (Con’t)Water Features (Con’t)• Lakes, Streams and RiversLakes, Streams and Rivers

– LakeLake•Water completely surrounded by landWater completely surrounded by land•Most are freshwaterMost are freshwater

– StreamStream•Body of water flowing, which combines to Body of water flowing, which combines to

create riverscreate rivers

– RiverRiver•A stream of considerable volume of waterA stream of considerable volume of water•Generally started by melting glacier, top of Generally started by melting glacier, top of

mountain or overflowing lakemountain or overflowing lake

Water Features (Con’t)Water Features (Con’t)• GroundwaterGroundwater

– Lies beneath earth’s surface and Lies beneath earth’s surface and supplies wells and springssupplies wells and springs

– Main source of groundwater is rain and Main source of groundwater is rain and melted icemelted ice

• Water CycleWater Cycle– Regular movement of water from ocean Regular movement of water from ocean

to air to ground to Oceanto air to ground to Ocean– Cycle Begins with EvaporationCycle Begins with Evaporation

•Changing liquid water into vapor or gasChanging liquid water into vapor or gas

Section 2-Section 2-1515

Section 3Section 3

• Earth’s ResourcesEarth’s Resources

Importance of ResourcesImportance of Resources• Natural ResourcesNatural Resources

– Elements from the earth that are not made by Elements from the earth that are not made by humans but can be used by themhumans but can be used by them

• Minerals and FuelsMinerals and Fuels– MineralsMinerals

• Substances from earth that are not living or from Substances from earth that are not living or from living thingsliving things

– Fossils FuelsFossils Fuels• Fuels derived from the remains of plants and animals Fuels derived from the remains of plants and animals

that lived millions of years agothat lived millions of years ago

• ExampleExample– Coal, oil, gasCoal, oil, gas

Importance of Resources Importance of Resources (Con’t)(Con’t)

• Minerals and Fuels (Con’t)Minerals and Fuels (Con’t)– Value of ResourcesValue of Resources

•Determined by the purpose of the ResourceDetermined by the purpose of the Resource

•Supply, often influenced by location, also Supply, often influenced by location, also affects valueaffects value

– Oil debate todayOil debate today

Managing ResourcesManaging Resources

• Renewable ResourcesRenewable Resources– Replace itself naturally or farmed to Replace itself naturally or farmed to

create a continuous supplycreate a continuous supply•Vegetables, Sun/Wind powerVegetables, Sun/Wind power

• Non-Renewable ResourcesNon-Renewable Resources– Can never be replacedCan never be replaced– Many minerals and fossil fuelsMany minerals and fossil fuels

Distribution of ResourcesDistribution of Resources• Most resources are not evenly distributed Most resources are not evenly distributed

throughout the earththroughout the earth

• TradeTrade– ImportImport

• Resources or goods brought into a countryResources or goods brought into a country

– ExportExport• Resources or goods sent from one country to anotherResources or goods sent from one country to another

• Uneven distribution of earth’s resources Uneven distribution of earth’s resources has led to an interdependence between has led to an interdependence between countriescountries– Also has led to many conflicts and warsAlso has led to many conflicts and wars

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