Chapter 1Chapter 1Introduction to Earth Introduction to Earth

ScienceScience

Overview of Earth ScienceOverview of Earth Science Earth Science is the Earth Science is the namename for the group of for the group of

sciencessciences that deals with that deals with EarthEarth and its and its neighbors in neighbors in spacespace..

Earth science includes many subdivisions of Earth science includes many subdivisions of geology such as geology such as geochemistrygeochemistry, , geophysicsgeophysics, , geobiologygeobiology and and paleontologypaleontology, , oceanographyoceanography, , meteorologymeteorology and and astronomyastronomy..

Section 1.2 A view of EarthSection 1.2 A view of Earth If you were up in space and you looked down If you were up in space and you looked down

on Earth, what would you see?on Earth, what would you see? The Earth’s physical environment is divided The Earth’s physical environment is divided

into into three majorthree major spheres: spheres: hydrospherehydrosphere, , atmosphereatmosphere and and geospheregeosphere HydrosphereHydrosphere pertains to the water portion of our pertains to the water portion of our

plantplant Atmosphere Atmosphere is the earth’s gaseos envelopeis the earth’s gaseos envelope GeosphereGeosphere is the rocks and crust is the rocks and crust Biosphere: living and non living things.Biosphere: living and non living things.

Plate TectonicsPlate Tectonics There are There are twotwo types of forces affecting Earth’s types of forces affecting Earth’s

surfacesurface.. Destructive forcesDestructive forces such as weathering and erosion that such as weathering and erosion that

wear away high points and make them flat.wear away high points and make them flat. Constructive forcesConstructive forces such as mountain building and such as mountain building and

volcanism build up the surface by raising the land and volcanism build up the surface by raising the land and depositing new material in the form of lava. depositing new material in the form of lava.

In the early part of the In the early part of the 2020thth century century a revolution a revolution began when the idea that the continents had moved began when the idea that the continents had moved about the about the face face of the Earthof the Earth

Global GridGlobal Grid Scientists use Scientists use 2 special2 special Earth measurements to Earth measurements to

describe location.describe location. LatitudeLatitude is the distance north or south of the is the distance north or south of the

equator, measured in degreesequator, measured in degrees LongitudeLongitude is the distance east or west of the prime is the distance east or west of the prime

meridian, measured in degrees. meridian, measured in degrees. Earth is 360 degrees in Earth is 360 degrees in circumference circumference

Longitude

Latitude

The line of The line of latitudelatitude around the middle of the around the middle of the globe, at globe, at 0 degrees0 degrees, is the , is the equatorequator

The The prime meridianprime meridian is the is the longitudelongitude that marks that marks degree of longitude. degree of longitude.

Lines of latitude and longitude form a Lines of latitude and longitude form a global global gridgrid that allows you to state your that allows you to state your exact exact locationlocation..

The equator divides the earth in The equator divides the earth in 2 halves2 halves called thecalled the northern northern and and southern hemispheressouthern hemispheres

The The prime meridianprime meridian and the and the 180 meridian180 meridian divide the earth into divide the earth into eastern and western eastern and western hemisphereshemispheres..

Q) How does the global grid divide Earth?Q) How does the global grid divide Earth?

Maps and MappingMaps and Mapping A map is a A map is a flat representationflat representation of Earth’s surface. of Earth’s surface.

(Remember the Earth is round)(Remember the Earth is round) No matter what kind of No matter what kind of map map is made, some is made, some

portion of the surface will always look either portion of the surface will always look either too too smallsmall, too big, or , too big, or out of placeout of place. Mapmakers . Mapmakers have, however, found ways to limit the have, however, found ways to limit the distortiondistortion of shape, of shape, sizesize, distance, and , distance, and directiondirection..

There are several different types of maps that There are several different types of maps that are made differently to accommodate the people are made differently to accommodate the people using them. using them.

Mercator ProjectionMercator Projection Created in 1959 by Gerardus Mercator to help Created in 1959 by Gerardus Mercator to help

sailors sailors navigatenavigate around Earth. around Earth. The lines of The lines of longitude are parallellongitude are parallel, making the , making the

grid grid rectangularrectangular Size and Size and distancedistance are are distorteddistorted, but shows , but shows

direction direction accuratelyaccurately Still used by seagoing navigators todayStill used by seagoing navigators today

Mercator ProjectionMercator Projection

Projection MapsProjection Maps Robinson projectionRobinson projection maps show most maps show most

distancesdistances, size, and , size, and shapes accuratelyshapes accurately. . Distorted around the edges of the map. Distorted around the edges of the map.

Conic projectionConic projection maps are made by wrapping maps are made by wrapping a a cone of papercone of paper around a globe at a particular around a globe at a particular line of line of latitudelatitude, and various points are , and various points are projectedprojected onto the paper. onto the paper. Distortion occurs in areas away from the latitude.Distortion occurs in areas away from the latitude. Used for road and weather maps. Used for road and weather maps.

Gnomonic projectionsGnomonic projections are made by placing a are made by placing a piece of paper on a globe so that it piece of paper on a globe so that it touchestouches a a single point on the globe’s surface.single point on the globe’s surface. Various points and lines are projected onto the Various points and lines are projected onto the

paper. paper. Distance and directionDistance and direction are distorted are distorted Allows Allows sailorssailors to accurately determine distance to accurately determine distance

and direction across the and direction across the oceansoceans.. Q) What major problem must mapmakers Q) What major problem must mapmakers

overcomeovercome A) Representing round Earth on flat paper A) Representing round Earth on flat paper

causes distortion in shape, size, distance. causes distortion in shape, size, distance.

Conic ProjectionConic Projection

Topographic MapsTopographic Maps A A topographic maptopographic map represents Earth’s represents Earth’s three- three-

dimensionaldimensional surface in two dimensions surface in two dimensions Topographic maps differ from the other maps Topographic maps differ from the other maps

discussed so far because topographic maps discussed so far because topographic maps show elevationshow elevation. Topographical maps show . Topographical maps show elevation of Earth’s surface by means of elevation of Earth’s surface by means of contour linescontour lines. .

Most show Most show bodies of waterbodies of water and and roadsroads Important for Important for geologistsgeologists, hikers, , hikers, campers campers

Contour lines Contour lines Show the Show the elevation of landelevation of land Every position along a single contour line is the Every position along a single contour line is the same same

elevation.elevation. Adjacent contour lines represent Adjacent contour lines represent change in elevationchange in elevation.. Contour lines that form a circle represent a Contour lines that form a circle represent a hillhill The The closercloser the lines the the lines the steepersteeper the slope the slope A A depressiondepression is represented by circular contours that is represented by circular contours that

have have hachure markshachure marks.. Contour lines never Contour lines never touch or intersecttouch or intersect

Contour interval Contour interval Tells you the difference in Tells you the difference in elevation elevation between adjacent between adjacent

lineslinesQ) Q) How do topographic maps indicate change in elevationHow do topographic maps indicate change in elevation

Topographic mapsTopographic maps

ScaleScale A map represents a certain A map represents a certain amount of areaamount of area on on

Earth’s surface. It is important to be able to Earth’s surface. It is important to be able to determine determine distancedistance on a map and relate it to the on a map and relate it to the real worldreal world. .

A map is drawn to A map is drawn to scalescale where a certain distance where a certain distance on the map is equal to a on the map is equal to a certain distancecertain distance at the at the surfacesurface

A A bar scalebar scale is provided on the map. This allows is provided on the map. This allows you to use a ruler to measure the you to use a ruler to measure the distancedistance on the on the map and then line the map and then line the ruler ruler up to the bar to up to the bar to determine the distance represented. determine the distance represented.

Geologic MapsGeologic Maps A A geologic mapgeologic map shows the type and age of the rocks shows the type and age of the rocks

that are exposed, or that are exposed, or crop outcrop out at the surface. at the surface. Once individual Once individual rock formationsrock formations are identified, and are identified, and

mapped out, their distribution and extent are drawn mapped out, their distribution and extent are drawn onto the map.onto the map.

Each rock formation is assigned a Each rock formation is assigned a colorcolor and and sometimes a sometimes a patternpattern

Contour linesContour lines are often included to provide a more are often included to provide a more detaileddetailed and and usefuluseful map. map.

Advanced TechnologyAdvanced Technology Advanced technologyAdvanced technology is used to make maps is used to make maps

that are more accurate than ever beforethat are more accurate than ever before Today’s technology provides us with the Today’s technology provides us with the

ability to more ability to more precisely analyzeprecisely analyze Earth’s Earth’s physical properties. physical properties.

Scientists are able to use Scientists are able to use satellitessatellites and and computers to send and computers to send and receive datareceive data

Collecting data from a distance above Earth’s Collecting data from a distance above Earth’s surface is called surface is called remote sensingremote sensing. .

We can use this We can use this technologytechnology in our daily life. in our daily life. GPS (GPS (global positioning systemglobal positioning system) can provide maps ) can provide maps

in our cars.in our cars. GPS is used by GPS is used by ship and airplanesship and airplanes for navigation for navigation GPS is used to track GPS is used to track wildlifewildlife, study , study earthquakesearthquakes, ,

measure measure erosionerosion, and many other purposes., and many other purposes.

Section 1.3 AssessmentSection 1.3 Assessment 1. Describe the two sets of lines that are used 1. Describe the two sets of lines that are used

on globes and some maps.on globes and some maps. 2. What happens to the images on the globe 2. What happens to the images on the globe

when they are transferred to a flat surface?when they are transferred to a flat surface? 3. What is the purpose of contour lines on 3. What is the purpose of contour lines on

topographic maps?topographic maps? 4. What types of advanced technology are 4. What types of advanced technology are

used in mapmaking today?used in mapmaking today?

Section 1.4Section 1.4Earth System ScienceEarth System Science

Earth has many different parts or Earth has many different parts or spheresspheres that that interactinteract and and are are interconnectedinterconnected. .

This way of looking at Earth is called Earth system This way of looking at Earth is called Earth system science. Its aim to understand Earth as a system made up science. Its aim to understand Earth as a system made up of numerous of numerous interactinginteracting parts or parts or subsystemssubsystems. .

Using this type of approach, we hope to eventually Using this type of approach, we hope to eventually understand and solve many of our global understand and solve many of our global environmental environmental problemsproblems

Q) What is Earth system science?Q) What is Earth system science?

What is a system?What is a system? A system can be A system can be any sizeany size group of interacting group of interacting

parts that form a complex whole. parts that form a complex whole. Most Most natural systemsnatural systems are driven by sources of are driven by sources of

energy that move matter and/or energy that move matter and/or energyenergy from from one place to another. one place to another.

A A closed systemclosed system energy moves energy moves freelyfreely in and in and out of the system, but no out of the system, but no mattermatter enters or enters or leaves the system.leaves the system.

A A car coolingcar cooling system is an example of a system is an example of a closed closed systemsystem

In an In an open systemopen system both both energyenergy and and mattermatter flow flow into and out of the system. Most natural into and out of the system. Most natural systems are systems are openopen. .

An example of an open system would be An example of an open system would be river river systemsystem. .

Earth as a SystemEarth as a System The Earth receives power from The Earth receives power from two sourcestwo sources One source is the One source is the sunsun , which drives external , which drives external

processes that occur in the processes that occur in the atmosphereatmosphere, , hydrospherehydrosphere, and at , and at Earth’s surfaceEarth’s surface..

The Earth’s interior is the The Earth’s interior is the second sourcesecond source of of energy. Heat from the formation of Earth and energy. Heat from the formation of Earth and the continuous decay of the continuous decay of radioactive elementsradioactive elements produce produce volcanoesvolcanoes, earthquakes, and , earthquakes, and mountainsmountains..

The Earth’s systems areThe Earth’s systems are linked linked and so change and so change in one in one system system can cause change within another can cause change within another system. Ex. The eruption of a volcano can system. Ex. The eruption of a volcano can change the atmosphere, lithosphere, change the atmosphere, lithosphere, hydrosphere, and biosphere. hydrosphere, and biosphere.

Q) How do we know that Earth’s systems are Q) How do we know that Earth’s systems are connected?connected?

Humans Humans are also part of the are also part of the Earth systemEarth system Our actions produce Our actions produce changeschanges in all of the other in all of the other

parts of the parts of the Earth systemEarth system. . Burning Burning gasoline and coalgasoline and coal, building breakwaters, , building breakwaters,

disposal of waste, clearing land ect..disposal of waste, clearing land ect..

People and the EnvironmentPeople and the Environment EnvironmentEnvironment refers to everything that surrounds refers to everything that surrounds

and and influencesinfluences an organism. an organism. Some of these are Some of these are biologicalbiological and and socialsocial. Others . Others

areare nonliving nonliving, such as water, , such as water, airair, soil and , soil and rockrock. . Temperature,Temperature, humidity humidity, and , and sunlight sunlight are are

conditions that are also included. conditions that are also included. Most of Earth science can be characterized as Most of Earth science can be characterized as

environmental scienceenvironmental science

Q) What are examples of nonliving factors?Q) What are examples of nonliving factors? Environmental science focuses on the Environmental science focuses on the

relationshiprelationship between between people and naturepeople and nature.. Humans can have a Humans can have a large impactlarge impact on natural on natural

systems and systems and cannotcannot always adjust to changes always adjust to changes we make.we make.

ResourcesResources Include Include water and soilwater and soil, metallic and nonmetallic , metallic and nonmetallic

minerals, and minerals, and energyenergy Resources are commonly divided into Resources are commonly divided into two broadtwo broad

categories. categories. RenewableRenewable and and NonrewableNonrewable..

RenewableRenewable resources can be resources can be replenishedreplenished over over relatively relatively short timeshort time spans. spans.

Plants & animals for food, natural fibers for clothing, and Plants & animals for food, natural fibers for clothing, and forest. Wind, water, and sun are considered forest. Wind, water, and sun are considered renewablerenewable

NonrenewableNonrenewable resources would be things such as: resources would be things such as: Iron, aluminum, copper, oil, natural gas, and coal.Iron, aluminum, copper, oil, natural gas, and coal.

Although these and other resources continue to form, the Although these and other resources continue to form, the processes that create them are so processes that create them are so slowslow that it takes that it takes millionsmillions of years for significant deposits to of years for significant deposits to accumulateaccumulate. .

When the present supplies are When the present supplies are exhaustedexhausted, there will be , there will be no no moremore

Q) How do renewable and nonrenewable Q) How do renewable and nonrenewable resources differ?resources differ?

PopulationPopulation The population of the Earth is The population of the Earth is growing rapidlygrowing rapidly. .

By By 20102010 it is estimated that it is estimated that 7 billion7 billion people people will inhabit the Earth. will inhabit the Earth.

Currently there are approx. Currently there are approx. 6,607,558,4976,607,558,497 in in the world. the world.

The usage of our The usage of our natural resourcesnatural resources has has increased increased rapidlyrapidly with the population growth. with the population growth.

Environmental ProblemsEnvironmental Problems Some of the Some of the environmentalenvironmental problems scientist problems scientist

face are face are locallocal, regional, and some are , regional, and some are globalglobal.. Significant threats to the environment include Significant threats to the environment include air air

pollutionpollution, acid rain, , acid rain, ozone depletionozone depletion, and global , and global warming. warming.

The loss of The loss of fertile soilfertile soil to erosion, the disposal of to erosion, the disposal of toxic waste, and the toxic waste, and the contaminantscontaminants and depletion and depletion of water resources are also a of water resources are also a concernconcern. .

Knowledge about Earth and how it works is Knowledge about Earth and how it works is necessary to our survival an well being. necessary to our survival an well being. Resources are Resources are limitedlimited..

Section 1.4 AssessmentSection 1.4 Assessment 1. Why do scientist study Earth as a system?1. Why do scientist study Earth as a system? 2. If a system is a collection of interacting 2. If a system is a collection of interacting

parts, what happens when one of the parts is parts, what happens when one of the parts is changed?changed?

3. What are two sources of energy that power 3. What are two sources of energy that power Earth’s systems?Earth’s systems?

4. List three ways that humans affect Earth’s 4. List three ways that humans affect Earth’s systemssystems

Section 1.5Section 1.5What is Scientific Inquiry?What is Scientific Inquiry?

All science is based on All science is based on two assumptionstwo assumptions.. The natural world behaves in a consistent and The natural world behaves in a consistent and predictable predictable

mannermanner Through careful, Through careful, systematic studysystematic study, we can understand , we can understand

and explain the and explain the natural world’snatural world’s behavior. behavior. The development of new scientific knowledge The development of new scientific knowledge

involves some basic stepsinvolves some basic steps FirstFirst, scientist collect data through , scientist collect data through observationobservation and and

measurementmeasurement. These date are essential to science and . These date are essential to science and serve as the starting point for the serve as the starting point for the development theoriesdevelopment theories. .

HypothesisHypothesis OnceOnce data data have been gathered, scientists try to have been gathered, scientists try to

explain how or why things happens in the explain how or why things happens in the manner manner observedobserved. Scientists do this by stating . Scientists do this by stating a possible a possible explanationexplanation called a scientific called a scientific hypothesishypothesis. .

Before a hypothesis can become an Before a hypothesis can become an accepted accepted part of scientific knowledge, it must be part of scientific knowledge, it must be tested tested and analyzedand analyzed. .

Hypothesis that Hypothesis that failfail rigorous testing are rigorous testing are discardeddiscarded..

TheoryTheory When a hypothesis has survived extensive When a hypothesis has survived extensive

testing it becomes a testing it becomes a scientific theoryscientific theory.. A A scientific theoryscientific theory is well tested and widely is well tested and widely

accepted by the accepted by the scientific communityscientific community and best and best explains certain explains certain observable factobservable fact. .

Scientific MethodScientific Method The process of The process of gathering factsgathering facts through through

observations and formulating scientific observations and formulating scientific hypothesis and theorieshypothesis and theories is called the is called the scientific scientific methodmethod. .

Many scientific investigations involve the Many scientific investigations involve the following stepsfollowing steps 1) the collection of 1) the collection of scientific factsscientific facts through through

observation and observation and measurementmeasurement

2) the development of 2) the development of one or moreone or more working working hypothesishypothesis of models to explain these facts of models to explain these facts

3) development of 3) development of observationsobservations and and experimentsexperiments to to test the test the hypothesishypothesis, and , and

4) the acceptance, 4) the acceptance, modificationmodification, or rejection of the , or rejection of the hypothesis based on hypothesis based on extensive testingextensive testing. .

Section 1.5 AssessmentSection 1.5 Assessment 1. You have just come up with an explanation to a 1. You have just come up with an explanation to a

question that has bothered you for some time. What question that has bothered you for some time. What must you do to have your explanation become a must you do to have your explanation become a hypothesis.hypothesis.

2. What is the difference between a scientific theory 2. What is the difference between a scientific theory and a hypothesis.and a hypothesis.

3. When is a model useful in scientific investigations?3. When is a model useful in scientific investigations? 4. What happens if more than one hypothesis is put 4. What happens if more than one hypothesis is put

forward to explain the same observation?forward to explain the same observation?