Models of EarthModels of Earth

Globes are 3-Globes are 3-Dimensional Models of Dimensional Models of

the Earththe Earth

Types of MapsTypes of Maps►1. 1. PoliticalPolitical

Shows political (national and state) Shows political (national and state) boundariesboundaries

(like a globe)(like a globe)

Types of MapsTypes of Maps►1. Political1. Political►2. 2. RoadRoad

Shows Shows interstate system, highways, interstate system, highways, and smaller roadsand smaller roads, depending on the , depending on the mapmap

Used for navigation (getting from “here” Used for navigation (getting from “here” to “there”to “there”

Types of MapsTypes of Maps►1. Political1. Political►2. Road2. Road►3. 3. WeatherWeather

Shows pressure systems, cloud cover, Shows pressure systems, cloud cover, rainfall, rainfall, weather forecastsweather forecasts

Types of MapsTypes of Maps►1. Political1. Political►2. Road2. Road►3. Weather3. Weather►4. 4. BathymetricBathymetric

The The ocean floor, ocean featuresocean floor, ocean features Topography of the oceanTopography of the ocean

Types of MapsTypes of Maps► 1. Political1. Political► 2. Road2. Road► 3. Weather3. Weather► 4. Bathymetric4. Bathymetric► 5. 5. TopographicTopographic

Shows the Shows the differences in elevationdifferences in elevation (relief) of an area(relief) of an area

Shows Shows man-made featuresman-made features of the land of the land as well as its as well as its natural featuresnatural features

A. Paper Maps are Flat 2-A. Paper Maps are Flat 2-Dimensional Representations of Dimensional Representations of

Earth’s SurfaceEarth’s SurfaceProblems:•Not as accurate as a 3-D Globe model•Earth’s features become distorted (they don’t look right)

B. Map MakingB. Map Making► SurveyorsSurveyors

Use Use distance and elevationdistance and elevation information from information from known points to known points to create mapscreate maps

Known points of elevation are called: Known points of elevation are called: bench marksbench marks, , metal stakes placed in stone and metal stakes placed in stone and

marked with the location and elevationmarked with the location and elevation

AerialAerial (from the sky)(from the sky) photographyphotography also helps make mapsalso helps make maps

BenchmarksBenchmarks

Mauna Kea, Hawaii

Modern surveyors use:CompassInfrared theodolite& GPS

C.C. Map ProjectionsMap Projections►CartographersCartographers ( (map makersmap makers) )

illustrate world maps as a projection to illustrate world maps as a projection to reduce distortionreduce distortion

►MapMap projection projection – transferring a – transferring a curved surface (the Earth, sphere) to a curved surface (the Earth, sphere) to a flat one (the map).flat one (the map).

►Common map projections: Common map projections: Mercator, Mercator, Gnomonic Gnomonic (polar), and (Poly)(polar), and (Poly)conicconic

I.I. Mercator Projection MapMercator Projection Map

The mercator map projection shows the view of Earth as if a large cylinder of paper had been wrapped around the globe. This is the most common type of projection

Mercator Projection MapMercator Projection Map-Disadvantage Major distortion effects near the poles (land looks larger than what it really is)+Advantage Indicates true directions as straight lines of latitude and longitude, makes a rectangular grid pattern

II. II. Gnomonic or polarGnomonic or polar Projection MapProjection Map

A gnomonic or polar projected map is created as if a piece of paper had been placed on a point on the Earth.

III. (Poly)Conic Projection III. (Poly)Conic Projection MapMap

The (poly)conic map projection shows the view of Earth as if a large paper cone had been wrapped around the globe.This type of map is useful for mapping areas in the middle latitudes.

Identify the type of map Identify the type of map projection.projection.

► Write the name of the type of Write the name of the type of projection in your notesprojection in your notes

Review:Review: What type of halves is What type of halves is the Earth divided into?the Earth divided into?

• North-South Hemispheres are separated by the imaginary line called the Equator•East-West Hemispheres are separated by imaginary lines called the Prime Meridian (Greenwich Meridian) and the International Date Line

Latitude and LongitudeLatitude and LongitudeGrid of imaginary lines placed over Earth Grid of imaginary lines placed over Earth

Every location on the Earth has a specific latitude and longitude “address.”

LatitudeLatitude

•Latitude lines circle the Earth horizontally, parallel to the Equator (0 Degrees)•Latitude is measured in Degrees North or South of the equator (0-90 Degrees)•HHS is at 37° North Latitude

LongitudeLongitude

•Longitude lines are half-circles that extend vertically between the poles• Longitude is measured in Degrees East or West of the Prime Meridian (0-180 Degrees)•HHS is at 78° West Longitude

D. D. How do you know the size How do you know the size of landforms or the distance of landforms or the distance

between cities on a map?between cities on a map?

•The map scale indicates how the map’s features and distances compare with the actual Earth•The comparison is given as a ratio: 1:24,000

Map Scale as a RatioMap Scale as a Ratio►1 : 24,000 means that 1 : 24,000 means that 1 map unit1 map unit

equals =equals = 24,000 units on Earth24,000 units on Earth

E. How do you determine E. How do you determine direction on a map?direction on a map?

► Usually, most modern maps place Usually, most modern maps place North at the topNorth at the top► Compass RoseCompass Rose indicates indicates directiondirection

► Geographic North vs Magnetic NorthGeographic North vs Magnetic North► Are they the same?Are they the same?► No, because… No, because… ► the the Earth is tilted on its axisEarth is tilted on its axis

Earth Observing SystemEarth Observing SystemThe satellites in the Earth Observing Systems (EOS) will contain sensors to monitor global climate change.

Landsat Satellite ImagesLandsat Satellite Images

Global Positioning SystemGlobal Positioning System

GPS Satellite

GPS Ground Receiver

GPS is a system of satellites and receivers that allow accurate positioning on the Earth.24 satellites work together

Mapmaking & Technology Mapmaking & Technology

Computer Computer image image

modeled modeled from from

global global topographtopography provided y provided by NOAAby NOAA