Modeling the PlanetModeling the Planet

Maps and map makingMaps and map making

GlobeGlobe

Virtual GlobesVirtual Globes• http://www.virtual-globe.info/http://www.virtual-globe.info/• http://earth.google.com/http://earth.google.com/• http://worldwind.arc.nasa.gov/http://worldwind.arc.nasa.gov/• http://resources.esri.com/arcgisexplorer/http://resources.esri.com/arcgisexplorer/

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MapsMaps

Maps are used to represent the Earth Maps are used to represent the Earth or part of the Earth in an easily or part of the Earth in an easily accessible manner.accessible manner.

We often find these 3 types of mapsWe often find these 3 types of maps• Mercator ProjectionMercator Projection• Gnomonic ProjectionGnomonic Projection• Polyconic ProjectionPolyconic Projection

MercatorMercator

Cylindrical Projection MapCylindrical Projection Map

Gerardus MercatorGerardus Mercator

Don’t Write This DownDon’t Write This Down (5 March 1512 – 2 December 1594) (5 March 1512 – 2 December 1594)

was a was a FlemishFlemish cartographercartographer. He was . He was born in born in RupelmondeRupelmonde in the in the County of FlandersCounty of Flanders. He is . He is remembered for the remembered for the Mercator projectionMercator projection world mapworld map, , which is named after him. This which is named after him. This proved very useful to many later proved very useful to many later explorers. explorers.

GnomonicGnomonic

Azimuthal Projection MapAzimuthal Projection Map

PolyconicPolyconic

Conic Projection MapConic Projection Map

What Are They Good For?What Are They Good For?

http://www.progonos.com/furuti/MapProj/Normal/ProjTbl/projTbl.htmlhttp://www.progonos.com/furuti/MapProj/Normal/ProjTbl/projTbl.html

Longitude and LatitudeLongitude and Latitude

Lines of longitude and latitude are Lines of longitude and latitude are circles around the Earth.circles around the Earth.

LatitudeLatitude

Equator- The “great circle” that runs Equator- The “great circle” that runs around the middle of the Earth.around the middle of the Earth.

All other lines of latitude are smaller All other lines of latitude are smaller circles.circles.

These lines run from East to West These lines run from East to West and measure North to South.and measure North to South.

LongitudeLongitude

All lines of longitude are great circles.All lines of longitude are great circles. They run from North to South and measure They run from North to South and measure

East to West.East to West. Longitude is measured in degrees from the Longitude is measured in degrees from the

prime meridian, which passes through prime meridian, which passes through Greenwich, England.Greenwich, England.

Each degree of longitude can be further Each degree of longitude can be further split into 60 minutes and again into 60 split into 60 minutes and again into 60 seconds.seconds.

ScalesScales

Map scales relate map distance to Map scales relate map distance to real world distance.real world distance.

OrientationOrientation

A compass helps us A compass helps us find our direction.find our direction.

The Earth has two The Earth has two sets of poles. sets of poles. Geographic and Geographic and Magnetic poles.Magnetic poles.

Orienting the MapOrienting the Map

http://www.globalsecurity.org/military/library/policy/army/fm/3-25-26/ch11.htm

How we make mapsHow we make maps

Cartographers make maps by Cartographers make maps by viewing the land from a high viewing the land from a high elevation point.elevation point.

The map is created with the use of a The map is created with the use of a plane table.plane table.

This method of map making This method of map making dominated until the 1940’s.dominated until the 1940’s.

TechnologyTechnology

Today, map making can be a much Today, map making can be a much faster and more accurate process.faster and more accurate process.• Arial PhotographyArial Photography• RadarRadar• Satellite ImagerySatellite Imagery

We can make maps of the Earth, We can make maps of the Earth, Moon, and even Mars.Moon, and even Mars.

GPSGPS

http://www8.garmin.com/aboutGPS/

Topographic MapsTopographic Maps

Contour LinesContour Lines

The contour lines on a topographic The contour lines on a topographic map indicate lines of constant map indicate lines of constant elevation.elevation.

Contour lines form loopsContour lines form loops Contour lines never cross.Contour lines never cross. Contour lines always have equal Contour lines always have equal

increments.increments. The contour interval is often The contour interval is often

indicated on the mapindicated on the map

mapping_contours_001.pdfmapping_contours_001.pdf

Contour LinesContour Lines

http://raider.muc.edu/~mcnaugma/Topographic%20Maps/determining_contour_interval.htm

Slope and ElevationSlope and Elevation

The distance between contour lines The distance between contour lines shows you slope. shows you slope.

When contour lines are jam packed, When contour lines are jam packed, this indicates a steep drop off.this indicates a steep drop off.

The slope can be calculated by The slope can be calculated by dividing the change in elevation by dividing the change in elevation by the distance between two points.the distance between two points.

Elevation ProfileElevation Profile

http://www.heywhatsthat.com/profiler.html

Map ActivityMap Activity

Mapactivity2.docMapactivity2.doc

Local MapsLocal Maps

Maps can be downloaded from USGSMaps can be downloaded from USGS http://store.usgs.gov/b2c_usgs/usgs/http://store.usgs.gov/b2c_usgs/usgs/

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