chapter 2: the earth. ch.2:the earth sec 1: planet earth our solar system planets: m.v.e.m.j.s.u.n....

Chapter 2: The EarthChapter 2: The Earth

Ch.2:The EarthCh.2:The Earth Sec 1: Planet Earth Sec 1: Planet Earth

Our Solar SystemOur Solar SystemPlanets:Planets: M.V.E.M.J.S.U.N.M.V.E.M.J.S.U.N.

Space Matter:Space Matter:

o AsteroidsAsteroids– small, irregularly shaped planet like objects. – small, irregularly shaped planet like objects. Found in the asteroid belt in between the orbits of Mars & Found in the asteroid belt in between the orbits of Mars & Jupiter.Jupiter.

o CometsComets– Composed of ice dust particles & frozen gases, – Composed of ice dust particles & frozen gases, look like bright balls of light w/ long feathery tales.look like bright balls of light w/ long feathery tales.

o MeteoroidsMeteoroids– pieces of space debris- chunks of rock & – pieces of space debris- chunks of rock & iron. Usually burned up in Earthiron. Usually burned up in Earth’’s atmosphere. s atmosphere.


Getting to Know EarthGetting to Know EarthAbout 70 % of EarthAbout 70 % of Earth’’s surface is made up of water. Oceans, lakes, rivers, s surface is made up of water. Oceans, lakes, rivers,

& other bodies of water make up the Earth& other bodies of water make up the Earth’’ss HydrosphereHydrosphere..

30% of the Earth30% of the Earth’’s surface is land, this includes continents & islands. This s surface is land, this includes continents & islands. This land is known as the land is known as the LithosphereLithosphere. .

The air we breathe is apart of EarthThe air we breathe is apart of Earth’’s s AtmosphereAtmosphere, a layer of gases , a layer of gases extending 1,000 miles above Earthextending 1,000 miles above Earth’’s surface. Our atmosphere is s surface. Our atmosphere is composed of 78% Nitrogen, 21% Oxygen & 1% other gases.composed of 78% Nitrogen, 21% Oxygen & 1% other gases.

The part of Earth that supports life is the The part of Earth that supports life is the BiosphereBiosphere..

Ch.2:The EarthCh.2:The Earth Sec 2: Forces of Change Sec 2: Forces of Change

EarthEarth’’s Structures Structureo The The EarthEarth is composed of is composed of 3 layers3 layers. . The core (inner & outer), The core (inner & outer),

mantle, & the crust.mantle, & the crust.o At the center of the planet is a super hot, At the center of the planet is a super hot, solid inner coresolid inner core. .

4,000 miles below the Earth4,000 miles below the Earth’’s surface.s surface.o Surrounding the inner core is a liquid Surrounding the inner core is a liquid outer coreouter core. This is a liquid . This is a liquid

band of nickel & iron. This section begins at 1,800 miles below band of nickel & iron. This section begins at 1,800 miles below EarthEarth’’s surface.s surface.

o The layer that contains thick, dense rock is know as the The layer that contains thick, dense rock is know as the MantleMantle.. Consists of silicon, aluminum, iron, magnesium, oxygen & other Consists of silicon, aluminum, iron, magnesium, oxygen & other elements. This mixture continually rises, cools, sinks, warms up, elements. This mixture continually rises, cools, sinks, warms up, & rises again.& rises again.


Inside the EarthInside the Earth


Plate MovementPlate Movement

At one point in time, millions of years ago, the At one point in time, millions of years ago, the continents of the Earth formed what was continents of the Earth formed what was known as known as PangaeaPangaea. Over millions of years, . Over millions of years, this this ““super-continentsuper-continent”” has broken apart into has broken apart into small continents. The theory that the small continents. The theory that the continents were once joined then slowly continents were once joined then slowly drifted apart is known asdrifted apart is known as Continental DriftContinental Drift. .


More about plates . . .More about plates . . .o When the plates spread apart, When the plates spread apart, MagmaMagma, molten , molten

rock, is pushed up from the mantle & ridges rock, is pushed up from the mantle & ridges are formed. are formed.

o Plate TectonicsPlate Tectonics refers to all these movements refers to all these movements which create many of the Earthwhich create many of the Earth’’s physical s physical features. Majority of the time these movements features. Majority of the time these movements are gradual at only 4 inches a year (we canare gradual at only 4 inches a year (we can’’t t feel this movement). feel this movement).


Plates & Plate MovementPlates & Plate Movement


Colliding & Spreading PlatesColliding & Spreading Plates. . Subduction-Subduction- Mountains are created when a Mountains are created when a

sea plate collides with a continental plate.sea plate collides with a continental plate.


o Accretion-Accretion- pieces of Earth pieces of Earth’’s crust come s crust come together slowly as the sea plate slides under together slowly as the sea plate slides under the continental plate. the continental plate.

Ch.2:The EarthCh.2:The Earth Sec 2: Forces of Change Sec 2: Forces of ChangeColliding & Spreading Plates . . .cont.Colliding & Spreading Plates . . .cont.

o New land is created when two sea plates New land is created when two sea plates converge. This happens when one plates moves converge. This happens when one plates moves under another, forming island chains at the under another, forming island chains at the boundary. Sea plates can also pull apart in a boundary. Sea plates can also pull apart in a process known as process known as SpreadingSpreading..

o The resulting deep crack allows magma from The resulting deep crack allows magma from within the Earth to well up between plates. This within the Earth to well up between plates. This magma hardens to build undersea volcanic magma hardens to build undersea volcanic mountains or ridges. This occurs down the middle mountains or ridges. This occurs down the middle of the Atlantic Oceanof the Atlantic Ocean’’s floor, pushing Europe and s floor, pushing Europe and North America away from each other. North America away from each other.


Folds and FaultsFolds and Faults

Folds: Folds: Moving plates sometimes squeeze the Moving plates sometimes squeeze the EarthEarth’’s surface until it folds or bends, in s surface until it folds or bends, in layers of rock. layers of rock.

Fault :Fault :Plates also grind or slide past each Plates also grind or slide past each other, this creates cracks in the Earthother, this creates cracks in the Earth’’s s crust. Worldcrust. World’’s most famous fault is s most famous fault is San San Andreas Fault, Andreas Fault, in California.in California.


EarthquakesEarthquakeso Earth quakesEarth quakes: Sudden, violent movements of plates along : Sudden, violent movements of plates along

a fault line. Tension builds up along fault lines as the plates a fault line. Tension builds up along fault lines as the plates stick. The strain eventually becomes so intense that the stick. The strain eventually becomes so intense that the rocks suddenly snap and shift. This movement releases rocks suddenly snap and shift. This movement releases stored-up energy along the fault.stored-up energy along the fault.

o The Ring Of Fire The Ring Of Fire is one of the most earthquake prone is one of the most earthquake prone areas on the planet. The cities of areas on the planet. The cities of Kobe (Japan), San Kobe (Japan), San Francisco Francisco and and Los Angeles Los Angeles are located here. This is a zone are located here. This is a zone of earthquake and volcanic activity surrounding the Pacific of earthquake and volcanic activity surrounding the Pacific Ocean. It marks the boundary where the plates that cradle Ocean. It marks the boundary where the plates that cradle the Pacific meet the plates that hold the continents the Pacific meet the plates that hold the continents surrounding the Pacific.surrounding the Pacific.


o External forces such as wind and water also External forces such as wind and water also change the Earthchange the Earth’’s surface. Wind and water s surface. Wind and water movements involve 2 processes: Weathering movements involve 2 processes: Weathering and erosion.and erosion.

o Weathering:Weathering: The process that breaks down The process that breaks down rocks on Earthrocks on Earth’’s surface into smaller pieces.s surface into smaller pieces.

o Erosion:Erosion: The wearing away of Earth The wearing away of Earth’’s s surface by wind, glaciers and moving water. surface by wind, glaciers and moving water.


WeatheringWeathering Physical weatheringPhysical weathering: When large masses of rock : When large masses of rock

are physically broken down into smaller pieces. are physically broken down into smaller pieces. Ex: water seeps into the cracks of a rock, freezes, Ex: water seeps into the cracks of a rock, freezes, then expands, and causes the rock to split. then expands, and causes the rock to split.

Chemical Weathering: Chemical Weathering: Changes the chemical Changes the chemical makeup of a rock. Transforming its minerals or makeup of a rock. Transforming its minerals or combining them with new elements. Ex: water combining them with new elements. Ex: water mixed with Carbon Dioxide from the air easily mixed with Carbon Dioxide from the air easily dissolves certain rocks, such as limestone. dissolves certain rocks, such as limestone.


Wind and Glacier Wind and Glacier ErosionErosion

o The Chinese Yellow The Chinese Yellow River Basin :River Basin :is is thickly covered with thickly covered with loessloess, a fertile, , a fertile, yellow-gray soil yellow-gray soil deposited by the deposited by the wind. This is a type wind. This is a type of wind erosion.of wind erosion.

o Glaciers can also Glaciers can also cause weathering. cause weathering. When glaciers melt When glaciers melt and recede, in some and recede, in some places they leave places they leave behind large piles of behind large piles of rocks and debris rocks and debris known as known as Moraines.Moraines.

Ch.2:The EarthCh.2:The Earth Sec 3: Earth Sec 3: Earth’’s Waters Water

The Water CycleThe Water Cycleo The total amount of water on Earth doesnThe total amount of water on Earth doesn’’t change, t change,

however, the Earthhowever, the Earth’’s water is constantly moving– from the s water is constantly moving– from the oceans to the air, to the ground and finally back to the oceans to the air, to the ground and finally back to the oceans, this is known as the oceans, this is known as the Water CycleWater Cycle..

o The sun drives the cycle by evaporating water from EarthThe sun drives the cycle by evaporating water from Earth’’s s surface. surface. EvaporationEvaporation is the changing of liquid water into is the changing of liquid water into vapor or gas. vapor or gas.

o When warm air cools, it cannot retain all of its water vapor, When warm air cools, it cannot retain all of its water vapor, so the excess water vapor changes into liquid water, this so the excess water vapor changes into liquid water, this process is called process is called CondensationCondensation..

o Tiny droplets of water come together to form clouds. When Tiny droplets of water come together to form clouds. When the clouds gather move water than they can hold, they the clouds gather move water than they can hold, they release moisture, which falls to the Earth as release moisture, which falls to the Earth as PrecipitationPrecipitation– – rain, snow, sleet, hail.rain, snow, sleet, hail.


Bodies of Salt WaterBodies of Salt Watero OceansOceans– About 97 % of the Earth– About 97 % of the Earth’’s water consists of s water consists of

water that circles the planet, our 4 oceans: the Pacific, water that circles the planet, our 4 oceans: the Pacific, Atlantic, Indian, and Arctic. Atlantic, Indian, and Arctic.

o Seas, Gulfs, & BaysSeas, Gulfs, & Bays—are bodies of water that are —are bodies of water that are smaller than oceans and are often enclosed by land.smaller than oceans and are often enclosed by land.

o Desalination:Desalination: The process in which we remove the The process in which we remove the salt from ocean water and use it as a supply of salt from ocean water and use it as a supply of freshwater, is very expensive, and is still in the early freshwater, is very expensive, and is still in the early stages of developmentstages of development

Bodies of FreshwaterBodies of Freshwatero Only 3% of the EarthOnly 3% of the Earth’’s total water supply is freshwater. 2% s total water supply is freshwater. 2%

of Earthof Earth’’s total water supply is frozen in glaciers and s total water supply is frozen in glaciers and icecaps. Lakes, rivers, & streams also account for Earthicecaps. Lakes, rivers, & streams also account for Earth’’s s small supply of freshwater.small supply of freshwater.

o GroundwaterGroundwater– which is freshwater that lies beneath the – which is freshwater that lies beneath the EarthEarth’’s surface, comes from rain & melted snow that filters s surface, comes from rain & melted snow that filters through the soil & from water that seeps into the ground through the soil & from water that seeps into the ground from rivers & lakes. Wells & springs tap into the from rivers & lakes. Wells & springs tap into the groundwater & are important sources of freshwater for groundwater & are important sources of freshwater for people.people.

o AquiferAquifer :An underground porous rock layer often saturated :An underground porous rock layer often saturated with water in the form of streamswith water in the form of streams


chapter 2: the earth. ch.2:the earth sec 1: planet earth our solar system planets: m.v.e.m.j.s.u.n....

Documents

earth sec

earths surface

earths atmosphere

sea plates

forces of changecolliding

earths hydrosphere

forces of changeaccretion

forces of changemore