1. Chapter 2 – Mapping

2. Globes The Earth is so large that to study it we need a model The Earth is so large that to study it we need a model A globe is a model of Earth A globe is a model of Earth Globes do not always help us get from one place to another Globes do not always help us get from one place to another They are large, not easy They are large, not easy to transport, and not to transport, and not very detailed very detailed

3. Maps A two-dimensional representation of Earth’s surface A two-dimensional representation of Earth’s surface Because the Earth is three-dimensional, distortion of Earth’s features is a problem for on most maps Because the Earth is three-dimensional, distortion of Earth’s features is a problem for on most maps To reduce distortion, cartographers draw maps by using different projections or views of Earth. To reduce distortion, cartographers draw maps by using different projections or views of Earth.

4. 3 Types of Map Projections

5. 1. Mercator Projection – depicts Earth as if a large piece of paper was wrapped around it and the continents were outlined Positives: shows the whole world (except for extreme poles) on one continuous map Positives: shows the whole world (except for extreme poles) on one continuous map Distortions: areas near the poles Distortions: areas near the poles Uses: shows true direction in straight lines (sea Uses: shows true direction in straight lines (sea navigation) navigation)

6. 2. Gnomonic Projection – made as if a sheet of paper was placed on one point on Earth’s surface (usually one of the poles) Positives: shows polar regions accurately Positives: shows polar regions accurately Distortions: land masses away from the center point Distortions: land masses away from the center point Uses: planning ocean and air voyages Uses: planning ocean and air voyages

7. 3. Polyconic (Conic) Projection – made as if a cone of paper was wrapped around the Earth Positives: curved latitude and longitude lines and most landforms keep their true shape and size Positives: curved latitude and longitude lines and most landforms keep their true shape and size Distortions: areas away from the mid- latitudes Distortions: areas away from the mid- latitudes Uses: Mapping large areas of land in mid- latitudes Uses: Mapping large areas of land in mid- latitudes

8. Latitude and Longitude

9. Latitude and longitude lines help us find places on Earth Latitude and longitude lines help us find places on Earth The lines give each place on Earth an “address” The lines give each place on Earth an “address”

10. A Divided Earth Earth is divided into two hemisphere Earth is divided into two hemisphere Northern and Southern OR Eastern and Western Northern and Southern OR Eastern and Western The equator divides the Earth into the Northern and Southern Hemispheres The equator divides the Earth into the Northern and Southern Hemispheres The prime meridian divides the Earth into the Eastern and Western Hemispheres The prime meridian divides the Earth into the Eastern and Western Hemispheres

11. Earth’s Hemispheres

12. Latitude Latitude Also called parallels Also called parallels Drawn east to west along the Earth Drawn east to west along the Earth Measure 0° to 90° north and 0° to 90° south from the Equator Measure 0° to 90° north and 0° to 90° south from the Equator Equator is 0° latitude, Equator is 0° latitude, poles are 90° poles are 90° north and south north and south

13. Longitude Also called meridians Also called meridians Drawn north to south along the Earth Drawn north to south along the Earth Measure 0° to 180° east and 0° to 180° west from the Prime Meridian Measure 0° to 180° east and 0° to 180° west from the Prime Meridian Prime Meridian is 0° longitude, Prime Meridian is 0° longitude, and the International Date and the International Date Line is 180° longitude Line is 180° longitude

14. How does latitude and longitude look on Earth?

15. Map Scale A map scale compares the distance on a map to actual distance on Earth’s surface A map scale compares the distance on a map to actual distance on Earth’s surface We have 3 different types of map scales: We have 3 different types of map scales: Verbal Verbal Graphic Graphic Numeric Numeric

16. Verbal – expressed in words

17. Graphic – expressed by a line divided into segments

18. Numeric – expressed by a ratio

19. Small Scale vs. Large Scale The larger the scale the smaller the area shown, the smaller the scale the larger the area shown The larger the scale the smaller the area shown, the smaller the scale the larger the area shown It is all about the detail that the map shows! It is all about the detail that the map shows! Large scale maps – show small area of land with a lot of detail Large scale maps – show small area of land with a lot of detail Small scale maps – show large area of land with very little detail Small scale maps – show large area of land with very little detail

20. Example of a Small Scale Map

21. Example of a large scale map

22. Topographic Maps

23. Maps that show features of an area using contour lines Maps that show features of an area using contour lines Topographic maps can show natural and man-made features Topographic maps can show natural and man-made features Topographic maps can be used to show elevation of land, depression on Earth’s surface, and slope of the land Topographic maps can be used to show elevation of land, depression on Earth’s surface, and slope of the land

24. Contour lines are the narrow brown lines on a topographic map that show the lands elevation Contour lines are the narrow brown lines on a topographic map that show the lands elevation Contour lines connect points of the same elevation – they never cross and are always closed Contour lines connect points of the same elevation – they never cross and are always closed Contour Lines

25. The contour interval is the distance between two consecutive contour lines If point A is 500 feet and point B is at 1500 feet, what is the contour interval between the two points? 1500 – 500 = 1000 1000/2 = 500 A B

26. On a contour map, every 4th or 5th line will be darker and marked with a number – this is the contour index On a contour map, every 4th or 5th line will be darker and marked with a number – this is the contour index Contour Index

27. You can determine the steepness of the land by looking at the distance between the contour lines. You can determine the steepness of the land by looking at the distance between the contour lines. Steep slope = contour lines very close together Steep slope = contour lines very close together Gentle slope = contour lines far apart Gentle slope = contour lines far apart X Y Which is steeper? X or Y Y

28. You can show the highs and lows of a contour map using a profile You can show the highs and lows of a contour map using a profile

29. Topographic Map symbols are used to show both natural and man-made features: Topographic Map symbols are used to show both natural and man-made features: Water – blue Water – blue Wooded areas – green Wooded areas – green Man-made features – black (railroads, cemeteries, churches, schools) Man-made features – black (railroads, cemeteries, churches, schools) Benchmarks – show exact elevation (BMx256) Benchmarks – show exact elevation (BMx256) Depression contour – Depression contour –

30. Uses for Topographic Maps Uses for Topographic Maps City planners use them to plan a public works projects City planners use them to plan a public works projects Engineers use them to create road projects Engineers use them to create road projects Geologists use them in searching for coal, oil, and gas Geologists use them in searching for coal, oil, and gas You can use them for any outdoor fun! You can use them for any outdoor fun!

31. Mapmaking and Technology

32. The United States Geological Survey (USGS) has been creating maps since 1879 The United States Geological Survey (USGS) has been creating maps since 1879 At that time, mapmaking was a very dangerous career – cartographers would climb up to the highest point and sketch everything they saw At that time, mapmaking was a very dangerous career – cartographers would climb up to the highest point and sketch everything they saw Technology has changed this dramatically! Technology has changed this dramatically! Now, cartographers use radar and satellites to create maps Now, cartographers use radar and satellites to create maps

33. How do radar and satellites create maps? Radar Radar Radar devices send out radio signals which bounce off objects and then send signals back to computersRadar devices send out radio signals which bounce off objects and then send signals back to computers Then, the computers create images based on those signalsThen, the computers create images based on those signals

34. Satellites Satellites In 1972, NASA launched its first Landsat satellite.In 1972, NASA launched its first Landsat satellite. These satellites use sensors to detect changes in wavelengths of lightThese satellites use sensors to detect changes in wavelengths of light The signals are sent back to computers to create imagesThe signals are sent back to computers to create images False Color Imaging assigns different colors to different wavelengths of light reflected from different objectsFalse Color Imaging assigns different colors to different wavelengths of light reflected from different objects

35. A False Color Image of planet Earth

36. Global Positioning System (GPS) Powerful computers team up with satellites to form the Global Positioning System (GPS). Powerful computers team up with satellites to form the Global Positioning System (GPS). This system can identify a person’s position, speed, and time anywhere on Earth at anytime. This system can identify a person’s position, speed, and time anywhere on Earth at anytime. It is made of 24 It is made of 24 satellites that satellites that orbit Earth orbit Earth

37. It is controlled by a main control station in Colorado Springs, CO It is controlled by a main control station in Colorado Springs, CO Individuals with receivers can pick up broadcasts from the satellites and pinpoint their location Individuals with receivers can pick up broadcasts from the satellites and pinpoint their location GPS is used for various things such as studying coastline erosion, verifying business transactions, and studying earthquakes GPS is used for various things such as studying coastline erosion, verifying business transactions, and studying earthquakes With the help of the GPS, maps are not just on paper anymore! With the help of the GPS, maps are not just on paper anymore!