1. Objectives Vocabulary Compare and contrast latitude and longitude.
Describe how time zones vary.
Vocabulary
cartography
equator
latitude
longitude
prime meridian
International Date Line

2. Latitude and Longitude
For thousands of years, people have used maps to define borders and to find places.
Cartography is the science of mapmaking.
Cartographers use an imaginary grid of parallel lines and vertical lines to locate points on Earth.
The equator circles Earth halfway between the north and south poles separating Earth into two equal halves called the northern hemisphere and the southern hemisphere.

3. Latitude Lines of latitude are lines running parallel to the equator.
Latitude and Longitude
Latitude
Lines of latitude are lines running parallel to the equator.
Latitude is the distance in degrees north or south of the equator.

4. Latitude and Longitude
Latitude is thus measured from 0° at the equator to 90° at the poles.
Locations north of the equator are referred to by degrees north latitude (N).
Locations south of the equator are referred to by degrees south latitude (S).

5. Latitude Degrees of Latitude
Latitude and Longitude
Latitude
Degrees of Latitude
Each degree of latitude is equivalent to about 111 km on Earth’s surface.
To locate positions on Earth more precisely, cartographers break down degrees of latitude into 60 smaller units, called minutes (´).
A minute of latitude can be further divided into seconds (´´).
Longitude is also divided into degrees, minutes, and seconds.

6. Latitude and Longitude
To locate positions in east and west directions, cartographers use lines of longitude, also known as meridians.
Longitude is the distance in degrees east or west of the prime meridian.
The prime meridian, representing 0° longitude, is the reference point for longitude.

7. Latitude and Longitude
Points west of the prime meridian are numbered from 0° to 180° west longitude (W).
Points east of the prime meridian are numbered from 0° to 180° east longitude (E).

8. Longitude Semicircles Degrees of Longitude
Latitude and Longitude
Longitude
Semicircles
Lines of longitude are not parallel; they are large semicircles that extend vertically from pole to pole.
Degrees of Longitude
The distances covered by degrees of longitude vary with location.
One degree of longitude varies from about 111 km at the equator to essentially the distance covered by a point at the poles.

9. Longitude Locating Places with Coordinates
Latitude and Longitude
Longitude
Locating Places with Coordinates
Both latitude and longitude are needed to precisely locate positions on Earth.
For example, the location of New Orleans is 29°57´N, 90°04´W.
Note that latitude comes first in reference to the coordinates of a particular location.

10. Latitude and Longitude

11. Latitude and Longitude
Time Zones
Because Earth takes about 24 hours to rotate once on its axis, it is divided into 24 times zones, each representing a different hour.

12. Latitude and Longitude
Time Zones
Each time zone is 15° wide, corresponding roughly to lines of longitude.
Time zone boundaries have been adjusted in local areas for convenience.

13. Time Zones There are six different time zones in the United States.
Latitude and Longitude
Time Zones
There are six different time zones in the United States.

14. Time Zones Calendar Dates
Latitude and Longitude
Time Zones
Calendar Dates
Every time zone experiences this transition from one day to the next, with the calendar advancing to the next day at midnight.
Each time you travel through a time zone, you gain or lose time, eventually gaining or losing an entire day.
The International Date Line, or 180° meridian, serves as the transition line for calendar days.
Traveling west across the International Date Line, you would advance your calendar one day.
Traveling east, you would move your calendar back one day.

15. Latitude and Longitude
Section Assessment
1. Match the following terms with their definitions.
___ latitude
___ longitude
___ prime meridian
___ equator D B A C
A. the reference point for longitude
B. the distance in degrees east or west of 0°
C. the reference point for latitude
D. the distance in degrees north or south of 0°

16. Latitude and Longitude
Section Assessment
2. If it is 10 A.M. in Madagascar, what time is it in Washington, D.C.?
It is 2 A.M. in Washington, D.C.

17. Latitude and Longitude
Section Assessment
3. Identify whether the following statements are true or false.
_______ A degree of longitude always represents the same distance.
_______ If you travel west across the International Date Line, you advance your calendar one day.
_______ Lines of latitude are not perfectly parallel to each other.
_______ When referencing a specific place on Earth by its coordinates, latitude always comes first.
false
true

18. End of Section 1

19. Objectives Vocabulary Compare and contrast different map projections.
Types of Maps
Objectives
Compare and contrast different map projections.
Analyze topographic maps.
Describe map characteristics, such as map scales and map legends
Vocabulary
Mercator projection
conic projection
gnomonic projection
topographic map
contour line
contour interval
map legend
map scale

20. Types of Maps
Types of Maps
Maps are flat models of a three-dimensional object, Earth.
All flat maps distort to some degree either the shapes or the areas of landmasses.
Cartographers use projections to make maps.
A map projection is made by transferring points and lines on a globe’s surface onto a sheet of paper.

21. Types of Maps
Mercator Projections
A Mercator projection is a map that has parallel lines of latitude and longitude.
In a Mercator projection, the shapes of the landmasses are correct, but their areas are distorted.

22. Types of Maps
Conic Projections
A conic projection is a map made by projecting points and lines from a globe onto a cone.
The cone touches the globe at a particular line of latitude along which there is very little distortion in the areas or shapes of landmasses.
Distortion is evident near the top and bottom of the projection.

23. Types of Maps
Gnomonic Projections
A gnomonic projection is a map made by projecting points and lines from a globe onto a piece of paper that touches the globe at a single point.
Gnomonic projections distort direction and distance between landmasses.
Gnomonic projections are useful in plotting long-distance trips by air or sea.

24. Types of Maps
Gnomonic Projections
Great circles are imaginary lines that divide Earth into two equal halves.
On a sphere such as Earth, the shortest distance between two points lies along a great circle.
Navigators connect points on gnomonic projections to plot great-circle routes.

25. Types of Maps
Topographic Maps
Topographic maps are detailed maps showing the elevations of hills and valleys of an area.
Topographic maps use lines, symbols, and colors to represent changes in elevation and features on Earth’s surface.

26. Topographic Maps Contour Lines
Types of Maps
Topographic Maps
Contour Lines
Elevation on a topographic map is represented by a contour line.
A contour line connects points of equal elevation.
Elevation refers to the distance of a location above or below sea level.

27. Topographic Maps Contour Intervals
Types of Maps
Topographic Maps
Contour Intervals
Topographic maps use contour lines to show changes in elevation.
The contour interval is the difference in elevation between two side-by-side contour lines.
The contour interval is dependent on the terrain.

28. Topographic Maps Index Contours
Types of Maps
Topographic Maps
Index Contours
Index contours are contour lines that are marked by numbers representing their elevations.
If a contour interval on a map is 5 m, you can determine the elevations represented by other lines around the index contour by adding or subtracting 5 m from the elevation indicated on the index contour.

29. Topographic Maps Depression Contour Lines
Types of Maps
Topographic Maps
Depression Contour Lines
Depression contour lines are used to represent features that are lower than the surrounding area.
On a map, depression contour lines have hachures, or short lines at right angles to the contour line that point toward the lower elevation, to indicate depressions.

30. Types of Maps
Map Legends
Topographic maps and most other maps include both human-made and natural features that are located on Earth’s surface.
These features are represented by different symbols.
A map legend explains what the symbols represent.

31. Types of Maps
Map Scales
When using a map, you need to know how to measure distances.
A map scale is the ratio between distances on a map and actual distances on the surface of Earth.

32. Types of Maps
Map Scales
There are three types of map scales: verbal scales, graphic scales, and fractional scales.
A verbal scale expresses distance as a statement, such as “One centimeter is equal to one kilometer.”
A graphic scale consists of a line that represents a certain distance, such as 5 km or 5 miles.
A fractional scale expresses distance as a ratio, such as 1:

33. Types of Maps
Section Assessment
1. Match the following terms with their definitions.
___ projection
___ contour interval
___ map legend
___ map scale C A D B
A. the difference in elevation between two side-by-side contour lines
B. a diagram that explains what the symbols on a map represent
C. a map made by transferring points and lines on a globe’s surface onto a sheet of paper
D. the ratio between distances on a map and actual distances on the surface of Earth

34. Types of Maps
Section Assessment
2. Which type of map would be best suited for the following applications?
___ An aviator is trying to identify the shortest route between New York and London.
___ A cartographer for the state department of transportation has been tasked with making a new state road map.
___ A group of friends is planning on hiking in the back country of Idaho.
___ A sailor is sailing up the coast from South America to North America. C B D A
A. Mercator projection
B. conic projection
C. gnomonic projection
D. topographic

35. Types of Maps
Section Assessment
3. What does it mean if a map says “Scale 1: ”?
This fractional scale means that one unit on the map represents units on Earth’s surface. For example, one inch on the map would equal inches on Earth’s surface.

36. End of Section 2

37. Objectives Vocabulary
Remote Sensing
Objectives
Compare and contrast the different forms of radiation in the electromagnetic spectrum.
Discuss how satellites and sonar are used to map Earth’s surface and its oceans.
• Describe the Global Positioning System.
Vocabulary
remote sensing
electromagnetic spectrum
frequency
Landsat satellite
Topex/Poseidon satellite
Global Positioning System
sonar

38. Remote Sensing
Remote Sensing
Until recently, mapmakers had to go on-site to collect the data needed to make maps.
Today, advanced technology has changed the way maps are made.
Remote sensing is the process of collecting data about Earth from far above Earth’s surface.

39. The Electromagnetic Spectrum
Remote Sensing
The Electromagnetic Spectrum
Satellites detect different wavelengths of energy reflected or emitted from Earth’s surface.
This energy has both electric and magnetic properties and is referred to as electromagnetic radiation.
Electromagnetic radiation includes visible light, gamma rays, X rays, ultraviolet waves, infrared waves, radio waves, and microwaves.

40. The Electromagnetic Spectrum
Remote Sensing
The Electromagnetic Spectrum
Wave Characteristics
All electromagnetic waves travel at the speed of km/s in a vacuum, a value commonly referred to as the speed of light.
Electromagnetic waves have distinct wavelengths and frequencies.
The electromagnetic spectrum is the arrangement of electromagnetic radiation according to wavelengths.
Frequency is the number of waves that pass a particular point each second.
These unique characteristics help determine how the energy is used by different satellites to map Earth.

41. The Electromagnetic Spectrum
Remote Sensing
The Electromagnetic Spectrum
Wave Characteristics

42. Remote Sensing
Landsat Satellites
A Landsat satellite receives reflected wavelengths of energy emitted by Earth’s surface, including some wavelengths of visible light and infrared radiation.
Since the features on Earth’s surface radiate warmth at slightly different frequencies, they show up as different colors in images

43. Topex/Poseidon Satellite
Remote Sensing
Topex/Poseidon Satellite
The Topex/Poseidon satellite uses radar to map features on the ocean floor.
Radar uses high-frequency signals that are transmitted from the satellite to the surface of the ocean.
A receiving device then picks up the returning echo as it is reflected off the water.

44. Topex/Poseidon Satellite
Remote Sensing
Topex/Poseidon Satellite
The distance to the water’s surface is calculated using the known speed of light and the time it takes for the signal to be reflected.
Variations in time indicate the presence of certain features on the ocean floor.

45. The Global Positioning System
Remote Sensing
The Global Positioning System
The Global Positioning System, or GPS, is a radio-navigation system of at least 24 satellites that allows its users to determine their exact position on Earth.
Each satellite orbits Earth and transmits high-frequency microwaves that contain information about the satellite’s position and the time of transmission.
A GPS receiver calculates the user’s precise latitude and longitude by processing the signals emitted by multiple satellites.

46. Remote Sensing
Sea Beam
Sea Beam technology is similar to the Topex/ Poseidon satellite in that it is used to map the ocean floor.
Sea Beam is located on a ship and relies on sonar to map ocean-floor features.
Sonar is the use of sound waves to detect and measure objects underwater.

47. Remote Sensing
Sea Beam
First, a sound wave is sent from a ship toward the ocean floor.
A receiving device then picks up the returning echo when it bounces off the seafloor.
Computers on the ship can then calculate the distance to the ocean bottom based on the time it takes the signal to be reflected.

48. Remote Sensing
Section Assessment
1. Match the following terms with their definitions.
___ remote sensing
___ frequency
___ Landsat
___ Topex/Poseidon B D A C
A. a satellite that receives reflected wavelengths of energy emitted by Earth’s surface
B. the process of collecting data about Earth from far above Earth’s surface
C. a satellite that uses radar to map features on the ocean floor
D. the number of waves that pass a particular point each second

49. Remote Sensing
Section Assessment
2. Number the following wave types beginning with the longest wavelength.
___ Infrared radiation
___ Visible light
___ X rays
___ Radio waves
___ Gamma rays
___ Microwaves
___ Ultraviolet radiation 3 4 6 1 7 2 5

50. Section Assessment 3. How does the Global Positioning System work?
Remote Sensing
Section Assessment
3. How does the Global Positioning System work?
Each Global Positioning Satellite orbits Earth and transmits high frequency microwaves that contain information about the satellite’s position and the time of transmission. The orbits of the satellites are arranged so that signals from several satellites can be picked up at any given moment by a GPS user equipped with a receiver. The receiver calculates the user’s precise latitude and longitude by processing the signals emitted by multiple satellites.

51. End of Section 3

52. Chapter Resources Menu
Study Guide
Section 2.1
Section 2.2
Section 2.3
Chapter Assessment
Image Bank
Chapter Resources Menu

53. Section 2.1 Study Guide
Section 2.1 Main Ideas
Cartographers use a grid system to locate exact positions on Earth. Lines of latitude refer to distances north and south of the equator. Lines of longitude refer to distances east and west of the prime meridian.
Earth is divided into 24 time zones. Each zone represents a different hour. The International Date Line, or 180° meridian, is the transition line for calendar days. The calendar advances to the next day in each time zone at midnight.

54. Section 2.2 Study Guide
Section 2.2 Main Ideas
Maps are flat models of Earth’s surface. All maps contain some sort of distortion in the shapes or areas of landmasses.
Maps are made by transferring points and lines on a globe onto paper. Mercator projections and gnomonic projections are commonly used for navigation by ships and planes. Conic projections are best suited for mapping small areas.
Topographic maps show changes in elevation of Earth’s surface. Contour lines connect points of equal elevation. A map legend explains the symbols on a map. A map scale shows the relationship between distances on a map and actual distances on Earth.

55. Section 2.3 Study Guide
Section 2.3 Main Ideas
The process of gathering data about Earth from far above the planet is called remote sensing. The electromagnetic spectrum shows the arrangement of electromagnetic radiation, which is often used by remote-sensing devices to map Earth.
Landsat satellites use visible light and infrared radiation to map Earth’s surface. The Topex/Poseidon satellite uses radar to map features on the ocean floor.
The Global Positioning System is a satellite-based navigation system that allows a user to pinpoint his or her exact location on Earth.

56. Chapter Assessment
Multiple Choice
1. Which of the following is NOT true about lines of latitude.
a. They are parallel to each other.
b. They connect the north and south poles.
c. They are either referenced as north or south.
d. Latitude is measured from 0º to 90º.
Lines of latitude are parallel to the equator. The equator is 0º and each pole is 90º. Lines of longitude connect the north and south pole.

57. Multiple Choice 2. What is the reference point for lines of longitude?
Chapter Assessment
Multiple Choice
2. What is the reference point for lines of longitude?
a. the equator
b. the International Date Line
c. the prime meridian
d. Earth’s center
The prime meridian, which runs through Greenwich, England, is 0º longitude. The equator is the reference for latitude. The International Date Line, which is 180º E or W, is opposite the prime meridian. Earth’s center is used to find the line of latitude but it is not a reference point.

58. Chapter Assessment
Multiple Choice
3. What represents equal elevation on a topographical map?
a. great circles c. hachures
b. a map scale d. contour lines
Great circles represent the shortest distance between two points on a sphere. A map scale is the ratio between distances on a map and actual distances on the surface of Earth. Hachures are short lines at right angles to the contour line, to indicate depressions.

59. Chapter Assessment
Multiple Choice
4. What is the distance between one degree of longitude?
a. 111 km
b. 48 km
c. 2 km
d. all of the above
Remember the lines of longitude are not parallel. The distance between lines of longitude ranges from 111 km to essentially the distance covered by a point at the poles.

60. Chapter Assessment
Multiple Choice
5. The Topex/Poseidon satellite uses _____ to map features on the ocean floor.
a. radar c. gamma rays
b. sonar d. GPS
Sea Beam uses sonar, which is the use of sound waves to detect and measure objects underwater. Gamma rays are at the high end of the electromagnetic spectrum, beyond the frequency that radar uses. GPS is the global positioning system which is a navigation system.

61. Chapter Assessment
Short Answer
6. What characteristic do all electromagnetic waves share?
All electromagnetic waves travel at the speed of km/s in a vacuum, a value commonly referred to as the speed of light.

62. Chapter Assessment
Short Answer
7. If it is 6:00 P.M. on July 4 in Los Angeles, California, what day and time is it in Tokyo, Japan?
It would be 10:00 A.M. on July 5.

63. Chapter Assessment
True or False
8. Identify whether the following statements are true or false.
______ Contour lines can cross each other.
______ There are 3600 seconds in a degree.
______ By connecting points on a gnomonic projection, navigators can plot great-circle routes.
______ The United States has six time zones.
______ If you travel east across the International Date Line, you would move your calendar back one day.
false
true

64. Image Bank
Chapter 2 Images

65. Image Bank
Chapter 2 Images

66. Image Bank
Chapter 2 Images

67. Image Bank
Chapter 2 Images

68. To navigate within this Interactive Chalkboard product:
Click the Forward button to go to the next slide.
Click the Previous button to return to the previous slide.
Click the Chapter Resources button to go to the Chapter Resources slide where you can access resources such as assessment questions that are available for the chapter.
Click the Menu button to close the chapter presentation and return to the Main Menu. If you opened the chapter presentation directly without using the Main Menu this will exit the presentation. You also may press the Escape key [Esc] to exit and return to the Main Menu.
Click the Help button to access this screen.
Click the Earth Science Online button to access the Web page associated with the particular chapter with which you are working.
Click the Speaker button to hear the vocabulary term and definition when available.
Help

69. End of Custom Shows This slide is intentionally blank.