The Earth is a rocky sphere that spins on its axis and orbits the Sun. It has a molten iron core, surrounded by a mantle and crust. The atmosphere protects life from space hazards and the greenhouse effect maintains a livable temperature. Radioactive dating indicates the Earth is approximately 4.5 billion years old, and its interior structure and motions are driven by convection currents caused by radioactive decay. Plate tectonics shapes the surface through rifting and subduction.

1. The EarthThe Earth
Arny, 3Arny, 3rdrd
Edition, Chapter 5Edition, Chapter 5

2. The Earth 2
The Earth As A PlanetThe Earth As A Planet
 IntroductionIntroduction
 In simple terms, the Earth is a huge, rocky sphereIn simple terms, the Earth is a huge, rocky sphere
spinning in space and moving around the Sun tospinning in space and moving around the Sun to
the tune of about 100 miles every few secondsthe tune of about 100 miles every few seconds
 Earth also has a blanket of air and a screen ofEarth also has a blanket of air and a screen of
magnetism that protects the surface and its lifemagnetism that protects the surface and its life
forms from the hazards of interplanetary spaceforms from the hazards of interplanetary space
 Shape and sizeShape and size
 Then Earth is large enough for gravity to haveThen Earth is large enough for gravity to have
shaped it into a sphereshaped it into a sphere
 Earth’s spinning makes its equator bulge into aEarth’s spinning makes its equator bulge into a
shape referred to as an oblate spheroid – a resultshape referred to as an oblate spheroid – a result
of inertiaof inertia

3. The Earth 3
The Earth As A PlanetThe Earth As A Planet
 Composition of the EarthComposition of the Earth
 The most common elements of the Earth’s surfaceThe most common elements of the Earth’s surface
rocks are: oxygen (45.5% by mass), siliconrocks are: oxygen (45.5% by mass), silicon
(27.2%), aluminum (8.3%), iron (6.2%), calcium(27.2%), aluminum (8.3%), iron (6.2%), calcium
(4.66%), and magnesium (2.76%)(4.66%), and magnesium (2.76%)
 Silicon and oxygen usually occur together asSilicon and oxygen usually occur together as
silicatessilicates
 Ordinary sand is the silicate mineral quartz andOrdinary sand is the silicate mineral quartz and
is nearly pure silicon dioxideis nearly pure silicon dioxide
 Much of Earth’s interior is the mineral olivine, aMuch of Earth’s interior is the mineral olivine, a
iron-magnesium silicate with a olive green coloriron-magnesium silicate with a olive green color
 Earth’s interior composition is determined fromEarth’s interior composition is determined from
analyzing seismic waves and the Earth’s densityanalyzing seismic waves and the Earth’s density

4. The Earth 4
The Earth As A PlanetThe Earth As A Planet
Density of EarthDensity of Earth
 DensityDensity is a measure of how much materialis a measure of how much material
(mass) is packed into a given volume(mass) is packed into a given volume
 Typical unit of density is grams per cubicTypical unit of density is grams per cubic
centimetercentimeter
 Water has a density of 1 g/cmWater has a density of 1 g/cm33
, ordinary, ordinary
surfacesurface rocks are 3 g/cmrocks are 3 g/cm33
, while iron is 8, while iron is 8
g/cmg/cm33
 For Earth, this density is found to be 5.5For Earth, this density is found to be 5.5
g/cmg/cm33
 Consequently, the Earth’s interior (core)Consequently, the Earth’s interior (core)
probably is iron (which is abundant inprobably is iron (which is abundant in
nature and high in density)nature and high in density)

5. The Earth 5
The Earth’s InteriorThe Earth’s Interior
IntroductionIntroduction
 Probing the interior with Earthquake wavesProbing the interior with Earthquake waves
 Earthquakes generateEarthquakes generate seismic wavesseismic waves thatthat
move through the Earth with speedsmove through the Earth with speeds
depending on the properties of the materialdepending on the properties of the material
through which they travelthrough which they travel
 These speeds are determined by timing theThese speeds are determined by timing the
arrival of the waves at remote points on thearrival of the waves at remote points on the
Earth’s surfaceEarth’s surface
 A seismic “picture” is then generated of theA seismic “picture” is then generated of the
Earth’s interior along the path of the waveEarth’s interior along the path of the wave

6. The Earth 6
The Earth’s InteriorThe Earth’s Interior
 Probing the interior with Earthquake wavesProbing the interior with Earthquake waves (continued)(continued)
 Seismic waves are of two types: S and PSeismic waves are of two types: S and P
 P waves compress material and travel easily through liquidP waves compress material and travel easily through liquid
or solidor solid
 S waves move material perpendicular to the wave directionS waves move material perpendicular to the wave direction
of travel and only propagate through solidsof travel and only propagate through solids
 Observations show P waves but no S waves atObservations show P waves but no S waves at
detecting stations on the opposite side of the Earthdetecting stations on the opposite side of the Earth
from the origin of an Earthquakefrom the origin of an Earthquake ⇒ the Earth has athe Earth has a
liquid coreliquid core
 Seismic studies show that the Earth’s interior hasSeismic studies show that the Earth’s interior has
four distinct regions:four distinct regions:
 A solid, low-density and thinA solid, low-density and thin crustcrust made mainly of silicatesmade mainly of silicates
 A hot, not-quite-liquid and thickA hot, not-quite-liquid and thick mantlemantle with silicateswith silicates
 AA liquid or outer coreliquid or outer core with a mixture of iron, nickel andwith a mixture of iron, nickel and
perhaps sulfurperhaps sulfur
 AA solid or inner coresolid or inner core of iron and nickelof iron and nickel

7. The Earth 7
The Earth’s InteriorThe Earth’s Interior
 Probing the interior with Earthquake wavesProbing the interior with Earthquake waves
(continued)(continued)
 The Earth is layered in such a fashion thatThe Earth is layered in such a fashion that
the densest materials are at the center andthe densest materials are at the center and
the least dense at the surface – this isthe least dense at the surface – this is
referred to asreferred to as differentiationdifferentiation
 The Earth’s inner core is solid because it isThe Earth’s inner core is solid because it is
under such high pressure (from overlyingunder such high pressure (from overlying
materials) that the temperature there is notmaterials) that the temperature there is not
high enough to liquefy it – this is not thehigh enough to liquefy it – this is not the
case for the outer liquid corecase for the outer liquid core

8. The Earth 8
The Earth’s InteriorThe Earth’s Interior
Heating the Earth’s CoreHeating the Earth’s Core
 The estimated temperature of the Earth’sThe estimated temperature of the Earth’s
core is 6500 Kcore is 6500 K
 This high temperature is probably due to atThis high temperature is probably due to at
least the following two causes:least the following two causes:
 Heat generation from the impact of small bodiesHeat generation from the impact of small bodies
that eventually formed the Earth by their mutualthat eventually formed the Earth by their mutual
gravitationgravitation
 TheThe radioactive decayradioactive decay ofof radioactive elementsradioactive elements
that occur naturally in the mix of materials thatthat occur naturally in the mix of materials that
made up the Earthmade up the Earth

9. The Earth 9
The Age of the EarthThe Age of the Earth
 Radioactive decay used to determine theRadioactive decay used to determine the
Earth’s ageEarth’s age
 Radioactive atoms decay intoRadioactive atoms decay into daughter atomsdaughter atoms
 The more daughter atoms there are relative to theThe more daughter atoms there are relative to the
original radioactive atoms, the older the rock isoriginal radioactive atoms, the older the rock is
 Radioactive potassium has a half-life of 1.28Radioactive potassium has a half-life of 1.28
billion years and decays into argon which is abillion years and decays into argon which is a
gas that is trapped in the rock unless it meltsgas that is trapped in the rock unless it melts
 Assume rock has no argon when originally formedAssume rock has no argon when originally formed
 Measuring the ratio of argon atoms to potassiumMeasuring the ratio of argon atoms to potassium
atoms gives the age of the rockatoms gives the age of the rock
 This method gives a minimum age of the Earth as 4This method gives a minimum age of the Earth as 4
billion yearsbillion years
 Other considerations put the age at 4.5 billion yearsOther considerations put the age at 4.5 billion years

10. The Earth 10
Motions in the Earth’s InteriorMotions in the Earth’s Interior
 IntroductionIntroduction
 Heat generated by radioactive decay in the EarthHeat generated by radioactive decay in the Earth
creates movement of rock calledcreates movement of rock called convectionconvection
 Convection occurs because hotter material will beConvection occurs because hotter material will be
less dense than its cooler surroundings andless dense than its cooler surroundings and
consequently will rise while cooler material sinksconsequently will rise while cooler material sinks
 Convection in the Earth’s InteriorConvection in the Earth’s Interior
 The crust and mantle are solid rock, althoughThe crust and mantle are solid rock, although
when heated, rock may develop convectivewhen heated, rock may develop convective
motionsmotions
 These convective motions are slow, but are theThese convective motions are slow, but are the
cause of: earthquakes, volcanoes, the Earth’scause of: earthquakes, volcanoes, the Earth’s
magnetic field, and perhaps the atmosphere itselfmagnetic field, and perhaps the atmosphere itself

11. The Earth 11
Motions in the Earth’s InteriorMotions in the Earth’s Interior
 Plate TectonicsPlate Tectonics
 RiftingRifting
 Hot,molten material rises from deep in the Earth’s interiorHot,molten material rises from deep in the Earth’s interior
in great, slow plumes that work their way to the surfacein great, slow plumes that work their way to the surface
 Near the surface, these plumes spread and drag theNear the surface, these plumes spread and drag the
surface layers from belowsurface layers from below
 The crust stretches, spreads, and breaks the surface in aThe crust stretches, spreads, and breaks the surface in a
phenomenon calledphenomenon called riftingrifting
 SubductionSubduction
 Where cool material sinks, it may drag crustal piecesWhere cool material sinks, it may drag crustal pieces
together buckling them upward into mountainstogether buckling them upward into mountains
 If one piece of crust slip under the other, the process isIf one piece of crust slip under the other, the process is
calledcalled subductionsubduction
 Rifting and subduction are the dominant forcesRifting and subduction are the dominant forces
that sculpt the landscape – they may also triggerthat sculpt the landscape – they may also trigger
earthquakes and volcanoesearthquakes and volcanoes

12. The Earth 12
Motions in the Earth’s InteriorMotions in the Earth’s Interior
Plate TectonicsPlate Tectonics (continued)(continued)
 The shifting of large blocks of the Earth’sThe shifting of large blocks of the Earth’s
surface is calledsurface is called plate tectonicsplate tectonics

13. The Earth 13
 IntroductionIntroduction
 Veil of gases around Earth constitutes its atmosphereVeil of gases around Earth constitutes its atmosphere
 Relative to other planetary atmospheres, the Earth’sRelative to other planetary atmospheres, the Earth’s
atmosphere is uniqueatmosphere is unique
 However, studying the Earth’s atmosphere can tell usHowever, studying the Earth’s atmosphere can tell us
about atmospheres in generalabout atmospheres in general
 Composition of the AtmosphereComposition of the Atmosphere
 The Earth’s atmosphere is primarily nitrogen (78.08%The Earth’s atmosphere is primarily nitrogen (78.08%
by number) and oxygen (20.95% by number)by number) and oxygen (20.95% by number)
 The remaining gases in the atmosphere (about 1%)The remaining gases in the atmosphere (about 1%)
includes: carbon dioxide, ozone, water, and argon,includes: carbon dioxide, ozone, water, and argon,
the first three of which are important for lifethe first three of which are important for life
 This composition is unique relative to the carbonThis composition is unique relative to the carbon
dioxide atmospheres of Mars and Venus and thedioxide atmospheres of Mars and Venus and the
hydrogen atmospheres of the outer large planetshydrogen atmospheres of the outer large planets
The Earth’s AtmosphereThe Earth’s Atmosphere

14. The Earth 14
The Earth’s AtmosphereThe Earth’s Atmosphere
 Origin of the AtmosphereOrigin of the Atmosphere
 Several theories to explain origin of Earth’sSeveral theories to explain origin of Earth’s
atmosphereatmosphere
 Release of gas (originally trapped when the EarthRelease of gas (originally trapped when the Earth
formed) by volcanism or asteroid impactsformed) by volcanism or asteroid impacts
 From materials brought to Earth by comet impactsFrom materials brought to Earth by comet impacts
 Early atmosphere different than todayEarly atmosphere different than today
 Contained much more methane (CHContained much more methane (CH44) and ammonia) and ammonia
(NH(NH33))
 Solar uv was intense enough to break out H from CHSolar uv was intense enough to break out H from CH44
NHNH33 and Hand H22O leaving carbon, nitrogen, and oxygenO leaving carbon, nitrogen, and oxygen
behind while the H escaped into spacebehind while the H escaped into space
 Ancient plants further increased the levels ofAncient plants further increased the levels of
atmospheric oxygen through photosynthesisatmospheric oxygen through photosynthesis

15. The Earth 15
The Earth’s AtmosphereThe Earth’s Atmosphere
The Ozone LayerThe Ozone Layer
 Oxygen in the atmosphere provides aOxygen in the atmosphere provides a
shield against solar uv radiationshield against solar uv radiation
 OO22 provides some shielding, but Oprovides some shielding, but O33, or, or
ozoneozone, provides most of it, provides most of it
 Shielding is provided by the absorption ofShielding is provided by the absorption of
uv photons by oxygen molecules (both Ouv photons by oxygen molecules (both O22
and Oand O33) and their resultant dissociation) and their resultant dissociation
 It is doubtful that life could exist on theIt is doubtful that life could exist on the
Earth’s surface without the ozone layerEarth’s surface without the ozone layer

16. The Earth 16
The Earth’s AtmosphereThe Earth’s Atmosphere
 The Greenhouse EffectThe Greenhouse Effect
 Visible light reaches the Earth’s surface and isVisible light reaches the Earth’s surface and is
converted to heatconverted to heat
 As a result, the surface radiates infrared energyAs a result, the surface radiates infrared energy
which is trapped by the blocking power of thewhich is trapped by the blocking power of the
atmosphere at infrared wavelengthsatmosphere at infrared wavelengths
 This reduces the rate of heat loss and makes theThis reduces the rate of heat loss and makes the
surface hotter than it would be otherwisesurface hotter than it would be otherwise
 This phenomenon is theThis phenomenon is the Greenhouse EffectGreenhouse Effect
 Water and carbon dioxide are two molecules thatWater and carbon dioxide are two molecules that
create the greenhouse effect through theircreate the greenhouse effect through their
absorption of infrared radiationabsorption of infrared radiation
 Atmospheric temperatures of Mars and VenusAtmospheric temperatures of Mars and Venus
directly related to COdirectly related to CO22 and the greenhouse effectand the greenhouse effect

17. The Earth 17
The Earth’s AtmosphereThe Earth’s Atmosphere
Structure of the AtmosphereStructure of the Atmosphere
 Atmosphere extends to hundreds ofAtmosphere extends to hundreds of
kilometerskilometers
 The atmosphere becomes less dense withThe atmosphere becomes less dense with
increasing altitudeincreasing altitude
 Half the mass of the atmosphere is withinHalf the mass of the atmosphere is within
the first 4 kilometersthe first 4 kilometers
 The atmosphere eventually merges withThe atmosphere eventually merges with
the vacuum of interplanetary spacethe vacuum of interplanetary space

18. The Earth 18
Earth’s Magnetic Field

19. The Earth 19
The Earth’s Magnetic FieldThe Earth’s Magnetic Field
 IntroductionIntroduction
 The Earth acts like a magnetic as indicated by itsThe Earth acts like a magnetic as indicated by its
affect on a compassaffect on a compass
 Magnetic forces are communicated by aMagnetic forces are communicated by a magneticmagnetic
fieldfield – direct physical contact is not necessary to– direct physical contact is not necessary to
transmit magnetic forcestransmit magnetic forces
 Magnetic field are depicted in diagrams byMagnetic field are depicted in diagrams by
magnetic lines of forcemagnetic lines of force
 Each line represents the direction a compass would pointEach line represents the direction a compass would point
 Density of lines indicate strength of fieldDensity of lines indicate strength of field
 Magnetic fields also haveMagnetic fields also have polaritypolarity – a direction– a direction
from a north magnetic pole to a south magneticfrom a north magnetic pole to a south magnetic
polepole
 Magnetic fields are generated either by large-scaleMagnetic fields are generated either by large-scale
currents or currents on an atomic scalecurrents or currents on an atomic scale

20. The Earth 20
The Earth’s Magnetic FieldThe Earth’s Magnetic Field
Origin of the Earth’s Magnetic FieldOrigin of the Earth’s Magnetic Field
 The magnetic field of the Earth is generatedThe magnetic field of the Earth is generated
by currents flowing in its molten iron coreby currents flowing in its molten iron core
 The currents are believed to be caused byThe currents are believed to be caused by
rotational motion and convection (magneticrotational motion and convection (magnetic
dynamo)dynamo)
 The Earth’s geographic poles and magneticThe Earth’s geographic poles and magnetic
poles do not coincidepoles do not coincide
 Both the position and strength of the polesBoth the position and strength of the poles
change slightly from year to year, evenchange slightly from year to year, even
reversing their polarity every 10,000 yearsreversing their polarity every 10,000 years
or soor so

21. The Earth 21
The Earth’s Magnetic FieldThe Earth’s Magnetic Field
 Magnetic effects in the upper atmosphereMagnetic effects in the upper atmosphere
 Earth’s magnetic field screens the planet fromEarth’s magnetic field screens the planet from
electrically charged particles emitted from the Sun,electrically charged particles emitted from the Sun,
which are often of an energy harmful to living cellswhich are often of an energy harmful to living cells
 The screening entails the Earth’s magnetic fieldThe screening entails the Earth’s magnetic field
deflecting the charged particles into spiraldeflecting the charged particles into spiral
trajectories and slowing them downtrajectories and slowing them down
 As the charged solar particles stream past Earth,As the charged solar particles stream past Earth,
they generate electrical currents in the upperthey generate electrical currents in the upper
atmosphereatmosphere
 These currents collide with and excite moleculesThese currents collide with and excite molecules
 As the molecules de-excite, light photons are givenAs the molecules de-excite, light photons are given
off resulting inoff resulting in AuroraAurora

22. The Earth 22
The Earth’s Magnetic FieldThe Earth’s Magnetic Field
Magnetic effects in the upperMagnetic effects in the upper
atmosphereatmosphere (continued)(continued)
 Region of the upper atmosphere whereRegion of the upper atmosphere where
the Earth’s magnetic field affects particlethe Earth’s magnetic field affects particle
motion is called themotion is called the magnetospheremagnetosphere
 Within the magnetosphere chargedWithin the magnetosphere charged
particles are trapped in two doughnutparticles are trapped in two doughnut
shaped rings that encircle the Earth andshaped rings that encircle the Earth and
are called theare called the Van Allen radiation beltsVan Allen radiation belts
 Van Allen belt particles are energeticVan Allen belt particles are energetic
enough to be a hazard to spacecraft andenough to be a hazard to spacecraft and
space travelersspace travelers

23. The Earth 23
Motions of the EarthMotions of the Earth
 IntroductionIntroduction
 Earth variety of motions include: spinning on its axis,Earth variety of motions include: spinning on its axis,
orbiting Sun, moving with Sun around the Milky Way,orbiting Sun, moving with Sun around the Milky Way,
and traveling through the Universe with the Milky Wayand traveling through the Universe with the Milky Way
 Rotational and orbital motions define the day and yearRotational and orbital motions define the day and year
and cause the seasonsand cause the seasons
 But our planet’s motions have other effectsBut our planet’s motions have other effects
 Air and Ocean Circulation: The Coriolis EffectAir and Ocean Circulation: The Coriolis Effect
 In the absence of any force an object will move in aIn the absence of any force an object will move in a
curved path over a rotating objectcurved path over a rotating object
 This apparent curved motion is referred to as theThis apparent curved motion is referred to as the
Coriolis effectCoriolis effect
 From space the Coriolis effect is a consequence ofFrom space the Coriolis effect is a consequence of
the rotating Earth moving under the direct path of athe rotating Earth moving under the direct path of a
moving objectmoving object

24. The Earth 24
Motions of the EarthMotions of the Earth
Air and ocean circulationAir and ocean circulation (continued)(continued)
 The Coriolis effect is responsible for:The Coriolis effect is responsible for:
 The spiral pattern of large storms as well as theirThe spiral pattern of large storms as well as their
direction of rotationdirection of rotation
 The trade winds that move from east to west inThe trade winds that move from east to west in
two bands, one north and one south of the equatortwo bands, one north and one south of the equator
 The direction of theThe direction of the Jet streamsJet streams, narrow bands of, narrow bands of
rapid, high-altitude windsrapid, high-altitude winds
 The atmospheric band structure of the rapidlyThe atmospheric band structure of the rapidly
rotating Jupiter, Saturn, and Neptunerotating Jupiter, Saturn, and Neptune
 The deflection of ocean currents creating flowsThe deflection of ocean currents creating flows
such as the Gulf Streamsuch as the Gulf Stream

25. The Earth 25
Motions of the EarthMotions of the Earth
 PrecessionPrecession
 As the Earth moves around the Sun over long periodsAs the Earth moves around the Sun over long periods
of time, the direction in which its rotation axis pointsof time, the direction in which its rotation axis points
changes slowlychanges slowly
 This changing in direction of the spin axis is calledThis changing in direction of the spin axis is called
precessionprecession
 Precession is caused by the Earth not being a perfectPrecession is caused by the Earth not being a perfect
sphere – its equatorial bulge allows the Sun andsphere – its equatorial bulge allows the Sun and
Moon to exert unbalanced gravitational forces thatMoon to exert unbalanced gravitational forces that
twist the Earth’s spin axistwist the Earth’s spin axis
 The Earth’s spin axis precesses around once everyThe Earth’s spin axis precesses around once every
26,000 years26,000 years
 Currently the spin axis points at Polaris – inCurrently the spin axis points at Polaris – in
A.D.A.D. 14,000 it will point nearly at the star Vega14,000 it will point nearly at the star Vega
 Precession may cause climate changesPrecession may cause climate changes

26. Light and Atoms
Photographs show that the Earth is round but the asteroid Gaspra is not. Gaspra is
too small for its gravity to make it spherical. (Courtesy NASA.)
Back

27. Light and Atoms
(A) Rotation makes the Earth's equator bulge. (B) Jupiter's rapid rotation creates an
equatorial bulge visible in this photograph. (Courtesy NASA.)
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28. Light and Atoms
Olivine (the greenish crystals) in a rock sample.
Back

29. Light and Atoms
Seismic waves spread out through Earth from an earthquake.
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30. Light and Atoms
P and S waves move through the Earth, but the S waves cannot travel through the
liquid core.
Back

31. Light and Atoms
An artist's view of the Earth's interior.
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32. Light and Atoms
Melting ice cream “differentiates” as the dense chocolate chips sink to the bottom of
the box. So too, melting has made much of the Earth's iron sink to its core.
Back

33. Light and Atoms
Heat readily escapes from small rocks but is retained in larger bodies. (Courtesy
NASA.)
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34. Light and Atoms
Examples of convection: (A) In our atmosphere, puffy cumulus clouds form when the
Sun heats the ground and warms the air so that it rises. (B) You can see rising and
sinking motions in a pan of heated soup. (C) An artist's view of convection in the
Earth's interior.
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35. Light and Atoms
(A) Rifting may occur where rising material reaches a planet's surface. (B) Subduction
builds mountains where material sinks back toward the interior of the Earth.
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36. Light and Atoms
Map of the Earth, showing its plates. Smaller plates include the Cocos (Co), Caribbean
(Ca), Juan de Fuca (Jf), Arabia (Ar), Philippines (Ph), and Scotia (Sc).
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37. Light and Atoms
Breakup of Pangea and the Earth today. Notice the close match of the African and
South American coastlines.
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38. Light and Atoms
Artist's view of the mid-Atlantic ridge (from World Ocean Floor by Bruce C. Heezen and
Marie Tharp, 1977) and the increasing age of rocks away from it.
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39. Light and Atoms
(A) Volcanic gas vent today. Gas from ancient eruptions built our atmosphere.
(Courtesy USGS.) (B) Planetesimals collide with young Earth and release gas—another
source of our atmosphere. (C) Comets striking young Earth and vaporizing. The
released gases contributed to our atmosphere.
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40. Light and Atoms
The greenhouse effect. Radiation at visible wavelengths passes freely through the
atmosphere and is absorbed at the ground. The ground heats up and emits infrared
radiation. Atmospheric gases absorb the infrared radiation and warm the atmosphere,
which in turn warms the ground.
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41. Light and Atoms
Schematic view of Earth's magnetic field lines and photograph of iron filings sprinkled
on a toy magnet, revealing its magnetic field lines.
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42. Light and Atoms
Electrically charged particles from the Sun spiral in the Earth's magnetic field.
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43. Light and Atoms
Photographs of an aurora from (A) the ground (courtesy Eugene Lauria) and
(B) from space. (Courtesy NASA.)
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44. Light and Atoms
Artist's view of the Van Allen radiation belts (side view).
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45. Light and Atoms
The Earth's many motions in space.
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46. Light and Atoms
Coriolis effect on a rock thrown toward the equator from the North Pole.
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47. Light and Atoms
Weather satellite pictures show clearly the spiral pattern of spinning air around a storm
that results from the Coriolis effect. (Courtesy NOAA.)
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48. Light and Atoms
Cloud bands on Jupiter created in part by the Coriolis effect. (Courtesy NASA/JPL.)
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49. Light and Atoms
Precession makes the Earth's rotation axis swing slowly in a circle.
Back