Mapping EarthChapter 1

Earth Science

Ch1 L.1 Maps

How can a map help determine location?Why are there different map projections for

representing Earth’s surface?

Ch1 L.1 BellworkMap view: drawn as if you were looking down on an area from above Earth’s

surfaceProfile view: a drawing that shows an object as though you were looking at it

from the sideMap legend: a key that lists all the symbols used on the mapMap scale: the relationship between a distance on the map and the actual

distance on the groundLongitude: distance in degrees east or west of the prime meridianLatitude: distance in degrees north or south of the equatorTime zone: the area of Earth’s surface between two meridians where people

use the same timeInternational Date Line: line of longitude 180° east or west of the prime

meridian

Understanding maps

A map is a model of Earth

globe= best representationmap= flattened version

Why are maps useful?Which is easier for you:

written directions or drawn directions?

Map viewsMap view: drawn as if you

were looking down on an area from above Earth’s surface

Profile view: drawn as if you were looking at an object from the side

Great for studying cross-sections of Earth

Map legends and scale

Map legendsA key that lists all

symbols used on the map

Gives definitions of symbols

Allow details to be placed on the map without cluttering it

Map legends and scale

Map scalerelationship between a

distance on the map and the actual distance on the ground

written different waysverbally writtenratio= 1:100 means one unit

on the map is 100 in real life

graphic= scale bar

Reading mapsLongitude: distance in

degrees East or West of the prime meridian

Passes through the North Pole and South Pole

Prime meridian= longitude that passes through Greenwich, England.

180 meridian= combines with prime meridian to divide the earth into East and West hemispheres

Reading mapsLatitude: the distance in

degrees north or south of the equator

Equator divides Earth into North and South

Lines are PARALLEL to each other

Equator is at 0°North pole is at 90°NSouth pole is at 90°S

Plotting locations

Minutes and secondsEach degree is divided

into 60 minutes (‘)Each minute is divided

into 60 seconds (‘’)

Plotting locations

Time zones: area on Earth’s surface between two meridians where people use the same time

Reference (start point) is the prime meridian

Earth is divided into 24 time zonesEach time zone has a width of

15° longitudeEach time zone changes by an

hour

Plotting locations

International Date Line: line of longitude 180° east or west of the prime meridian

Does not follow the prime meridian exactly

Map ProjectionsGlobe= no distortions of Earth’s

features since it has the same shapeCylindrical projections

Shapes near equator represented wellShapes near poles appear much larger than

real life

Conical projectionsLittle distortion near line of latitude where the

cone touches the globeDistortions everywhere elseALL projections distort the shapes of Earth

because they are flat and Earth is a sphere

Ch1 L.1 Homework

P.16 1-10Study for quiz CH1 L.1

Ch1 L.2 Technology and map making

What can a topographic map tell you about the shape of Earth’s surface?

What can you learn from geologic maps about the rocks near Earth’s surface?

How can modern technology be used in mapmaking?

Ch1 L.2 BellworkTopographic map: shows detailed shapes of Earth’s surface, along with its

natural and human-made featuresElevation: the height above sea level of any point on Earth’s surfaceRelief: the difference in elevation between the highest and lowest point in an areaContour line: lines on a topographic map that connect points of equal elevationContour interval: elevation difference between contours that are next to each

otherSlope: a measure of the steepness of the landGeologic map: shows the surface geology of the mapCross section: shows a vertical slice through rocks below Earth’s surfaceRemote sensing: process of collecting information about an area without coming

into physical contact with it

Types of general use-maps

Physical mapsuse lines/shading/color to

show features like lakes or mountains

Relief mapsuse shading and shadows

to identify mountains and flat areas

Types of general-use maps

Political mapsshows boundaries between

countries/states/counties

Road mapsshow interstates or roads to

help you find your way

Topographic mapsTopography= shape of land

surfaceTopographic map= shows shapes of

Earth’s surface along with human and man-made features

Contour lines= on topographic map show points of equal elevation

Can measure both elevation and reliefElevation= height above sea levelRelief= difference in elevation

between highest and lowest point

Topographic maps continuedInterpreting contours

not every line is labeledContour interval=

elevation difference between contour lines

Slope= steepness of the land

Contours far apart= flat

Contours close together= steep

Topographic maps continued

Topographic profilesInformation from

contour map can be used to draw a profile of the Earth’s surface

Can help you determine easiest way to travel

Topographic maps continuedSymbols on topographic

mapsContour lines

Brown on landBlue under water

ColorsGreen= vegetationWater= blueBlack shapes= buildingsPink shading= dense housing

in citiesPurple= new information

added after map was made

Geologic maps

Show the surface geology of the mapped area

rock types/ages, locations of faults

Geologic formationsrock unit with similar

origins, rock type and age

legends list symbols and age

Color in map= not necessarily color of rock

Geologic maps continued

Geologic cross sectionsHow can we see what’s

underground?Drill for a sampleLook at a cliff

cliff face is like profile view of the ground

Profile view of rocks below the ground is a cross-section

Making maps today

Global Positioning System (GPS):

Group of satellites used for navigation

a GPS receives signal from 3-4 satellites and calculates latitude and longitude to get location

Making maps today continuedGeographic Information

Systems (GIS):Computerized information

systems used to store and analyze map data

combines data from: satellites, scanners, aerial photographs

Can create different map layers of the same location

Making maps today continuedRemote sensing

Collecting information from an area without coming into physical contact with it

Monitoring change: satellites take pictures constantly and at different times of the day

Can use to look for differencesLandsat: series of satellites. Completes scan of Earth every 16 days

Launched in 1999. Can see changes in wetlands and coral reefs

TOPEX/Jason-1: pair of satellites used for ocean topography, circulation, sea tides and climate change

Sea Beam: Uses sonar to map the bottom of the ocean. ON a ship.

Ch1 L.2 Homework

p.29 1-8Study for quiz CH1 L.2Outline Ch1 L.2Study for Ch1 Test!