The Dynamic EarthThe Dynamic Earth

Chapter 3Chapter 3

Earth as a SystemEarth as a System

Geosphere – land 6,378 km radiusGeosphere – land 6,378 km radius

Atmosphere – mixture of gases, airAtmosphere – mixture of gases, air

Hydrosphere – water covers 2/3’sHydrosphere – water covers 2/3’s

Biosphere – life exists, 9 km above to Biosphere – life exists, 9 km above to the bottom of the oceanthe bottom of the ocean

Earths InteriorEarths Interior Each layer of the earth gets denser Each layer of the earth gets denser

the deeper it getsthe deeper it gets Three Compositional Layers:Three Compositional Layers: 1. 1. CrustCrust – outer layer, 5-8km under – outer layer, 5-8km under

the oceans, 20-70km under the the oceans, 20-70km under the continentscontinents

2. 2. MantleMantle – 2900km thick, medium – 2900km thick, medium dense 64%dense 64%

3. 3. CoreCore – radius of 3400 km, most – radius of 3400 km, most densedense

The GeosphereThe Geosphere

Five Physical Layers of the EarthFive Physical Layers of the Earth LithosphereLithosphere – cool, rigid layer, up to 300 – cool, rigid layer, up to 300

km, makes up the pieces called the km, makes up the pieces called the tectonic platestectonic plates

AsthenosphereAsthenosphere – plastic, solid layer of – plastic, solid layer of mantle that flows smoothly and the mantle that flows smoothly and the tectonic plates move on top of it, 250 kmtectonic plates move on top of it, 250 km

MesophereMesophere – lower part of the mantle, – lower part of the mantle, 2550 km2550 km

Outer CoreOuter Core – made of liquid nickel and – made of liquid nickel and iron, 2200 kmiron, 2200 km

Inner CoreInner Core – 1228 km, solid nickel and – 1228 km, solid nickel and ironiron

Plate TectonicsPlate Tectonics Continents are on the tectonic plates Continents are on the tectonic plates

and move with them and move with them Major tectonic plates are the Pacific, Major tectonic plates are the Pacific,

North American, South American, North American, South American, African, Eurasian and AntarcticAfrican, Eurasian and Antarctic

Geologic activity occurs at the Geologic activity occurs at the boundaries between tectonic platesboundaries between tectonic plates

Plates collide, pull apart, slip past each Plates collide, pull apart, slip past each other cause mountains to form, other cause mountains to form, earthquakes and volcanoesearthquakes and volcanoes

EarthquakesEarthquakes Fault – break in the crust that is where Fault – break in the crust that is where

earthquakes occurearthquakes occur Richter scale 2-9.5- measure of the Richter scale 2-9.5- measure of the

magnitude of an earthquake, each magnitude of an earthquake, each number is 31.7 times stronger than number is 31.7 times stronger than the number belowthe number below

VolcanoesRing of Fire Contains 75% of the worlds active volcanoes

Located on plate boundaries

ErosionErosion Removal and transport of surface Removal and transport of surface

materialmaterial 2 Types:2 Types:

Water Erosion – rivers and oceansWater Erosion – rivers and oceans

Wind Erosion – deserts and beachesWind Erosion – deserts and beaches

Atmosphere -Atmosphere - Mixture of gases surrounding earthMixture of gases surrounding earth Constantly changingConstantly changing Insulates thus keeping earth temperature Insulates thus keeping earth temperature

constantconstant Nitrogen makes up 78%Nitrogen makes up 78% O, Ar, CoO, Ar, Co22, methane, water vapor , methane, water vapor Atmospheric Dust-soil, salt, ash from Atmospheric Dust-soil, salt, ash from

fires, volcanic ash, pollen, bacteria, fires, volcanic ash, pollen, bacteria, virusesviruses

Air pressure is less dense the further outAir pressure is less dense the further out

Atmosphere – 4 layersAtmosphere – 4 layers 1.1.TroposphereTroposphere – area closest to the – area closest to the

ground, 18 km 75%of the gases, dust, ice ground, 18 km 75%of the gases, dust, ice and liquid water-Weather, Clouds, and and liquid water-Weather, Clouds, and smog occur heresmog occur here

2. 2. StratosphereStratosphere – 18-50 km Ozone – 18-50 km Ozone layer, temperature riseslayer, temperature rises

3. 3. MesosphereMesosphere – 50-80 km, coldest – 50-80 km, coldest layer, down to -92layer, down to -92oo C C

4. 4. ThermosphereThermosphere – contains the – contains the ionosphere where electrical charged ionosphere where electrical charged particles are (get AM radio at night when particles are (get AM radio at night when sun goes down, particles quit jumping)sun goes down, particles quit jumping)

Temperatures up to Temperatures up to 20002000ooCC

Energy Transfer occurs by:Energy Transfer occurs by: RadiationRadiation – electromagnetic waves, no – electromagnetic waves, no

contact but still feel it, moves from object contact but still feel it, moves from object with a higher temperature to one with a with a higher temperature to one with a lower temperaturelower temperature

Conduction –Conduction – direct contact, fast moving direct contact, fast moving molecules to slow moving moleculesmolecules to slow moving molecules

Convection Convection – density differences, air is – density differences, air is warmed, the air molecules move apart warmed, the air molecules move apart which increases the volume of air which which increases the volume of air which reduces its density thus the air raises and reduces its density thus the air raises and causes a circular movement of air called causes a circular movement of air called a convection currenta convection current

Green House EffectGreen House Effect Solar energy is trapped next to the Solar energy is trapped next to the

earth’s surface by the atmosphereearth’s surface by the atmosphere Gases that trap heat next to earth are Gases that trap heat next to earth are

called greenhouse gases: water vapor, called greenhouse gases: water vapor, carbon dioxide, methane and nitrous carbon dioxide, methane and nitrous oxideoxide

These gases keep earth warm enough These gases keep earth warm enough to support life as we know it.to support life as we know it.

Water Cycle

Water on EarthWater on Earth HydrosphereHydrosphere – all water on earth’s surface, – all water on earth’s surface,

covers 70% of earths surface, 97% salt water, covers 70% of earths surface, 97% salt water, of the remaining 3% - 2/3’s is frozen in the ice of the remaining 3% - 2/3’s is frozen in the ice caps of the south and north polescaps of the south and north poles

Water Cycle – Water Cycle – water constantly moves water constantly moves between the atmosphere and earth, sun between the atmosphere and earth, sun provides the energy for thisprovides the energy for this– EvaporationEvaporation - Heat from sun cause water to - Heat from sun cause water to

evaporate into the atmosphere into water evaporate into the atmosphere into water vapor vapor

– CondensationCondensation -Water vapor changes back into -Water vapor changes back into a liquid in the atmosphere as it cools, when it a liquid in the atmosphere as it cools, when it condenses it forms cloudscondenses it forms clouds

– PrecipitationPrecipitation – clouds cannot hold any more – clouds cannot hold any more water vapor, it falls as rain, snow, hail, sleetwater vapor, it falls as rain, snow, hail, sleet

rain is either absorbed by ground, runoff, or rain is either absorbed by ground, runoff, or evaporatesevaporates

Earth’s OceansEarth’s Oceans Make up over 70% of the earth’s surfaceMake up over 70% of the earth’s surface Major Oceans:Major Oceans: Pacific Ocean is the largest – deepest Pacific Ocean is the largest – deepest

area of all ocean is Challenger Deep, area of all ocean is Challenger Deep, 11,033 m below sea level, (deeper than 11,033 m below sea level, (deeper than Mt. Everest)Mt. Everest)

Atlantic Ocean- also North and southAtlantic Ocean- also North and south Indian Ocean Indian Ocean Arctic Ocean – smallest ocean covered by Arctic Ocean – smallest ocean covered by

ice, pack iceice, pack ice

Ocean WaterOcean Water Salinity – concentration of all the Salinity – concentration of all the

dissolved salts, average 3.5%dissolved salts, average 3.5% Composed of Sodium (31%) and Composed of Sodium (31%) and

Chlorine (55%)Chlorine (55%) Zones of the OceanZones of the Ocean Surface Zone – warm, sunlightSurface Zone – warm, sunlight Thermocline – area that gets coldThermocline – area that gets cold Deep Zone – average temperature 2Deep Zone – average temperature 2oo C C Functions to absorb and store solar Functions to absorb and store solar

energyenergy Currents move warm and cold waterCurrents move warm and cold water

BiosphereBiosphere

Closed system – matter in the Closed system – matter in the environmentenvironment

Open system - for energy, sunlightOpen system - for energy, sunlight