Chapter 3 Table of Contents Section 1 Finding Locations on Earth Models of the Earth Table of Contents Section 1 Finding Locations on Earth Section 2 Mapping Earth’s Surface Section 3 Types of Maps

Chapter 3 Objectives Distinguish between latitude and longitude. Section 1 Finding Locations on Earth Chapter 3 Objectives Distinguish between latitude and longitude. Explain how latitude and longitude can be used to locate places on Earth’s surface. Explain how a magnetic compass can be used to find directions on Earth’s surface.

Section 1 Finding Locations on Earth Chapter 3 Latitude The points at which Earth’s axis of rotation intersects Earth’s surface are used as reference points for defining direction. These points are the geographic North Pole and South Pole. Halfway between the poles, a circle called the equator divides Earth into the North and Southern Hemispheres. A reference grid that is made up of additional circles is used to locate places on Earth‘s surface.

Chapter 3 Latitude, continued Section 1 Finding Locations on Earth Chapter 3 Latitude, continued One set of circles describes positions north and south of the equator. These circles are known as parallels, and they express latitude. parallel any circle that runs east and west around Earth and tat is parallel to the equator; a line of latitude latitude the angular distance north or south from the equator; expressed in degrees

Chapter 3 Latitude, continued Section 1 Finding Locations on Earth The diagram below shows Earth’s parallels.

Chapter 3 Latitude, continued Degrees of Latitude Minutes and Seconds Section 1 Finding Locations on Earth Chapter 3 Latitude, continued Degrees of Latitude Latitude is measured in degrees, and the equator is 0° latitude. The latitude of both the North Pole and the South Pole is 90°. In actual distance, 1° latitude equals about 111 km. Minutes and Seconds Each degree of latitude consists of 60 equal parts, called minutes. One minute (symbol: °) of latitude equals 1.85 km. In turn, each minute is divided into 60 equal parts, called seconds (symbol: °).

Chapter 3 Longitude, continued Section 1 Finding Locations on Earth Chapter 3 Longitude, continued East-west locations are established by using meridians. meridian any semicircle that runs north and south around Earth from the geographic North Pole to the geographic South Pole; a line of longitude longitude the angular distance east or west from the prime meridian; expressed in degrees

Chapter 3 Longitude, continued Section 1 Finding Locations on Earth The diagram below shows Earth’s meridians.

Chapter 3 Longitude, continued Degrees of Longitude Section 1 Finding Locations on Earth Chapter 3 Longitude, continued Degrees of Longitude The meridian that passes through Greenwich, England is called the prime meridian. This meridian represents 0° longitude. The meridian opposite the prime meridian, halfway around the world, is labeled 180°, and is called the International Date Line. Distance Between Meridians The distance covered by a degree of longitude depends on where the degree is measured. The distance measured by a degree of longitude decreases as you move from the equator toward the poles.

Chapter 3 Finding Direction Section 1 Finding Locations on Earth One way to find direction on Earth is to use a magnetic compass. A magnetic compass can indicate direction because Earth has magnetic properties as if a powerful bar-shaped magnet were buried at Earth’s center at an angle to Earth’s axis of rotation. The areas on Earth’s surface just above where the poles of the imaginary magnet would be are called the geomagnetic poles. The geomagnetic poles and the geographic poles are located in different places.

Finding Direction, continued Section 1 Finding Locations on Earth Chapter 3 Finding Direction, continued Magnetic Declination The angle between the direction of the geographic pole and the direction in which the compass needle points is called magnetic declination. In the Northern Hemisphere, magnetic declination is measured in degrees east or west of the geographic North Pole. Because Earth’s magnetic field is constantly changing, the magnetic declinations of locations around the globe also change constantly. By using magnetic declination, a person can use a compass to determine geographic north for any place on Earth.

Finding Direction, continued Section 1 Finding Locations on Earth Chapter 3 Finding Direction, continued The diagram below shows the magnetic declination of the United States.

Finding Direction, continued Section 1 Finding Locations on Earth Chapter 3 Finding Direction, continued The Global Positioning System Another way people can find their location on Earth is by using the global positioning system, or GPS. GPS is a satellite navigation system that is based on a global network of 24 satellites that transmit radio signals to Earth’s surface. A GPS receiver held by a person on the ground receives signals from three satellites to calculate the latitude, longitude, and altitude of the receiver on Earth.

Section 2 Mapping Earth’s Surface Chapter 3 Objectives Explain two ways that scientists get data to make maps. Describe the characteristics and uses of three types of map projections. Summarize how to use keys, legends, and scales to read maps.

How Scientists Make Maps Section 2 Mapping Earth’s Surface Chapter 3 How Scientists Make Maps Because most globes are too small to show details of Earth’s surface, such as streams and highways, a great variety of maps have been developed for studying and displaying detailed information about Earth. The science of making maps is called cartography. Scientists who make maps are called cartographers. Cartographers use data from a variety of sources, such as from field surveys and remote sensing. remote sensing the process of gathering and analyzing information about an object without physically being in touch with the object

Chapter 3 Map Projections Section 2 Mapping Earth’s Surface A map is a flat representation of Earth’s curved surface. Transferring a curved surface to a flat map results in a distorted image of the curved surface. An area shown on a map may be distorted in size, shape, distance, or direction. Over the years, cartographers have developed several ways to transfer the curved surface of Earth onto flat maps. These methods are called map projections. map projection a flat map that represents a spherical surface No map projection is entirely accurate, but each kind of projection has advantages and disadvantages.

Map Projections, continued Section 2 Mapping Earth’s Surface Chapter 3 Map Projections, continued The diagram below shows a cylindrical projection.

Map Projections, continued Section 2 Mapping Earth’s Surface Chapter 3 Map Projections, continued The diagram below shows an azimuthal projection.

Map Projections, continued Section 2 Mapping Earth’s Surface Chapter 3 Map Projections, continued The diagram below shows a conic projection.

Chapter 3 Reading a Map Direction on a Map Section 2 Mapping Earth’s Surface Chapter 3 Reading a Map Maps provide information through the use of symbols. Direction on a Map Maps are commonly drawn with north at the top, east at the right, west at the left, and south at the bottom. Some maps use parallels of latitude and meridians of longitude to indicate direction and location. Many maps also include a compass rose, which is a symbol that indicates the cardinal directions (north, east, south, and west), or an arrow that indicates north.

Reading a Map, continued Section 2 Mapping Earth’s Surface Chapter 3 Reading a Map, continued Symbols Symbols are commonly used on maps to represent features such as cities, highways, rivers, and other points of interest. Symbols may resemble the features that they represent, or they may be more abstract. Symbols are commonly explained in a legend. legend a list of map symbols and their meanings

Reading a Map, continued Section 2 Mapping Earth’s Surface Chapter 3 Reading a Map, continued Map Scales scale the relationship between the distance shown on a map and the actual distance Map scales are commonly expressed as graphic scales, fractional scales, or verbal scales. A graphic scale is a printed line that has markings that represent units of measure, such as meters or kilometers. A fractional scale is a ratio that indicates how distance on Earth relates to distance on the map. A verbal scale expresses scale in sentence form.

Chapter 3 Section 3 Types of Maps Objectives Explain how elevation and topography are shown on a map. Describe three types of information shown in geologic maps. Identify two uses of soil maps.

Chapter 3 Topographic Maps Advantages of Topographic Maps Section 3 Types of Maps Topographic Maps One of the most widely used maps is called a topographic map, which shows the surface features of Earth. topography the size and shape of the land surface features of a region elevation the height of an object above sea level Advantages of Topographic Maps Topographic maps provide more detailed information about the surface of Earth than either drawings or .

Topographic Maps, continued Chapter 3 Section 3 Types of Maps Topographic Maps, continued Elevation on Topographic Maps On topographic maps, elevation is shown by using contour lines. contour line a line that connects points of equal elevation on a map The difference in elevation between one contour line and the next is called the contour interval. The contour interval is selected based on the relief of the area being mapped. relief the difference between the highest and lowest elevations in a given area Every fifth contour line is darker than the four lines one either side of it. This index contour makes reading elevation easier.

Topographic Maps, continued Chapter 3 Section 3 Types of Maps Topographic Maps, continued Landforms on Topographic Maps The spacing and direction of contour lines indicate the shapes of the landforms represented on a topographic map. Closely spaced contour lines indicate that the slope is steep. Widely spaced contour lines indicate that the land is relatively level.

Topographic Maps, continued Chapter 3 Section 3 Types of Maps Topographic Maps, continued Landforms on Topographic Maps, continued A contour line that bends to form a V shape indicates a valley. The bend in the V points toward the higher end of the valley; this V points upstream, or in the direction from which the water flows, if there is a stream. Contour lines that form closed loops indicate a hilltop or a depression. Closed loops that have short straight lines perpendicular to the inside of the loop indicate a depression.

Topographic Maps, continued Chapter 3 Section 3 Types of Maps Topographic Maps, continued The diagram below shows how topographic maps represent landforms.

Chapter 3 Geologic Maps Rock Units on Geologic Maps Section 3 Types of Maps Geologic Maps Geologic maps are designed to show the distribution of geologic features, such as the types of rocks found an a given area and the locations of faults, folds, and other structures. Rock Units on Geologic Maps On geologic maps, geologic units are distinguished by color. Units of similar ages are generally assigned colors in the same color family, such as different shades of blue. In addition to assigning a color, geologists assign a set of letters to each rock unit. This set of letters symbolizes the age of the rock and the name of the unit or the type of rock.

Chapter 3 Soil Maps Soil Surveys Section 3 Types of Maps Scientists construct soil maps to classify, map, and describe soils, based on surveys of soils in a given area. Soil Surveys A soil survey consists of three main parts: text, maps, and tables. The text includes general information about the geology, topography, and climate of the area. The tables describe the types and volumes of soils in the area. The maps show the approximate locations and types of the different soils.

Chapter 3 Other Types of Maps Section 3 Types of Maps Other Types of Maps Maps are useful to every branch of Earth science. Maps that show topography and rock and soil types are only one useful type of map. Some Earth scientists use maps to show the location and flow of both water and air. Other types of Earth scientists use maps to study changes in Earth’s surface over time.

Chapter 3 Maps in Action Topographic Map of the Desolation Watershed

Chapter 3 Multiple Choice Standardized Test Prep Multiple Choice How can you determine whether the contours on a topographic map show a gradual slope? A. Look for V-shaped contour lines. B. Look for widely spaced contour lines. C. Look for short, straight lines inside the loop. D. Look for tightly spaced, circular contour lines.

Multiple Choice, continued Chapter 3 Standardized Test Prep Multiple Choice, continued How can you determine whether the contours on a topographic map show a gradual slope? A. Look for V-shaped contour lines. B. Look for widely spaced contour lines. C. Look for short, straight lines inside the loop. D. Look for tightly spaced, circular contour lines.

Multiple Choice, continued Chapter 3 Standardized Test Prep Multiple Choice, continued 2. How far apart would two successive index contours be on a map with a contour interval of 5 meters? F. 5 meters G. 10 meters H. 20 meters I. 25 meters

Multiple Choice, continued Chapter 3 Standardized Test Prep Multiple Choice, continued 2. How far apart would two successive index contours be on a map with a contour interval of 5 meters? F. 5 meters G. 10 meters H. 20 meters I. 25 meters

Multiple Choice, continued Chapter 3 Standardized Test Prep Multiple Choice, continued 3. What part of a road map would you use in order to measure the distance from your current location to your destination? A. latitude lines B. map scale C. longitude lines D. map legend

Multiple Choice, continued Chapter 3 Standardized Test Prep Multiple Choice, continued 3. What part of a road map would you use in order to measure the distance from your current location to your destination? A. latitude lines B. map scale C. longitude lines D. map legend

Multiple Choice, continued Chapter 3 Standardized Test Prep Multiple Choice, continued 4. Meteorologists use isobars on a weather map in order to? F. show changes in atmospheric air pressure. G. connect points of equal temperature. H. plot local precipitation data. I. show elevation above or below sea level.

Multiple Choice, continued Chapter 3 Standardized Test Prep Multiple Choice, continued 4. Meteorologists use isobars on a weather map in order to? F. show changes in atmospheric air pressure. G. connect points of equal temperature. H. plot local precipitation data. I. show elevation above or below sea level.

Multiple Choice, continued Chapter 3 Standardized Test Prep Multiple Choice, continued 5. What is the angular distance, measured in degrees, east or west of the prime meridian? A. latitude B. longitude C. isogram D. relief

Multiple Choice, continued Chapter 3 Standardized Test Prep Multiple Choice, continued 5. What is the angular distance, measured in degrees, east or west of the prime meridian? A. latitude B. longitude C. isogram D. relief

Chapter 3 Short Response Standardized Test Prep Short Response 6. At what location on Earth does each new day begin at midnight?

Short Response, continued Chapter 3 Standardized Test Prep Short Response, continued 6. At what location on Earth does each new day begin at midnight? International Date Line

Short Response, continued Chapter 3 Standardized Test Prep Short Response, continued 7. What is the latitude of the North Pole?

Short Response, continued Chapter 3 Standardized Test Prep Short Response, continued 7. What is the latitude of the North Pole? 90°N

Reading Skills, continued Chapter 3 Standardized Test Prep Reading Skills, continued 11. Why does each map described display some sort of distortion?

Reading Skills, continued Chapter 3 Standardized Test Prep Reading Skills, continued 11. Why does each map described display some sort of distortion? Any time a curved surface is mapped on a flat surface, distortion occurs. This distortion can take different forms and each map type produces different amounts of distortion.

Interpreting Graphics Chapter 3 Standardized Test Prep Interpreting Graphics Use the figure below to answer questions 12–13. The figure shows the topography of the an area surrounding the Orr River.

Interpreting Graphics, continued Chapter 3 Standardized Test Prep Interpreting Graphics, continued 12. What location on the map has the steepest gradient? A. location A B. location B C. location C D. location D

Interpreting Graphics, continued Chapter 3 Standardized Test Prep Interpreting Graphics, continued 12. What location on the map has the steepest gradient? A. location A B. location B C. location C D. location D

Interpreting Graphics, continued Chapter 3 Standardized Test Prep Interpreting Graphics, continued 13. In which direction is the river in the topographic map flowing? What information on the map helped you determine your answer?

Interpreting Graphics, continued Chapter 3 Standardized Test Prep Interpreting Graphics, continued 13. In which direction is the river in the topographic map flowing? What information on the map helped you determine your answer? Answers should include the following: The river is flowing from northwest to southeast; the contour lines near the river form V shapes, and the tips of the Vs point upstream; the Vs in the map point to the northwest.

Interpreting Graphics, continued Chapter 3 Standardized Test Prep Interpreting Graphics, continued Use the figure below to answer questions 14–15. The figure shows Earth’s system of latitude and longitude lines. Lines are shown in 30° increments.

Interpreting Graphics, continued Chapter 3 Standardized Test Prep Interpreting Graphics, continued 14. Which point is located at 30°N, 60°E? F. point E G. point F H. point G I. point H

Interpreting Graphics, continued Chapter 3 Standardized Test Prep Interpreting Graphics, continued 14. Which point is located at 30°N, 60°E? F. point E G. point F H. point G I. point H

Interpreting Graphics, continued Chapter 3 Standardized Test Prep Interpreting Graphics, continued 15. The distance between two lines of latitude that are 1° apart is about 111 km. What is the approximate distance between points G and E?

Interpreting Graphics, continued Chapter 3 Standardized Test Prep Interpreting Graphics, continued 15. The distance between two lines of latitude that are 1° apart is about 111 km. What is the approximate distance between points G and E? 111 km/1°  60° = 6660 km