Chapter Introduction Lesson 1 Maps Lesson 2 Technology and Mapmaking Chapter Wrap-Up How are Earth’s surface features measured and modeled? What do you think? Before you begin, decide if you agree or disagree with each of these statements. As you view this presentation, see if you change your mind about any of the statements. Do you agree or disagree? 1. Maps help determine locations on Earth. 2. All Earth models are spherical. 3. World maps are drawn accurately for every location. Do you agree or disagree? 4. Topographic maps show changes in surface elevations. 5. The colors on geological maps show the colors of the surface rocks. 6. Satellites are far too far from Earth to collect useful information about Earth’s surface. Maps • How can a map help determine a location? • Why are there different map projections for representing Earth’s surface? Maps • map view • longitude • profile view • latitude • map legend • time zone • map scale • International Date Line Understanding Maps • A map is a model of Earth. • Most maps are drawn in map view— drawn as if you were looking down on an area from above Earth’s surface. • Map view is also known as plan view. • A profile view is a drawing showing a vertical “slice” through the ground. Understanding Maps (cont.) Maps have two features to help you read and understand the map: a series of symbols called a map legend, and a ratio, which establishes the map scale. Understanding Maps (cont.) A map legend is a key that lists all the symbols used on the map that help you interpret the symbols. map legend Understanding Maps (cont.) legend Science Use part of a map that explains the map symbols Common Use a story coming down from the past Understanding Maps (cont.) Model builders typically use scale to make the model measurements accurate to the measurements of the real object. Understanding Maps (cont.) A map scale is the relationship between a distance on the map and the actual distance on the ground. Reading Maps • Long ago, mapmakers created a grid system of two sets of imaginary lines, called longitude and latitude, which encircle Earth. • Mapmakers started the grid system with a vertical line that circled Earth and passes through the North Pole and the South Pole. Reading Maps (cont.) • The half of this vertical circle that passes through Greenwich, England, is known as the prime meridian. • The other half of this vertical circle is the 180° meridian. Reading Maps (cont.) Similar circles are drawn at every degree east and west of the prime meridian. These lines are referred to as lines of longitude. longitude from Latin longitudo, means “length” Reading Maps (cont.) • A location’s longitude is the distance in degrees east or west of the prime meridian. • The prime meridian and the 180° meridian divide Earth into the Eastern Hemisphere and the Western Hemisphere. Reading Maps (cont.) The lines east of the prime meridian are called east longitude, and the lines west of the prime meridian are called west longitude. Reading Maps (cont.) • Mapmakers also drew horizontal lines from east to west around Earth. The equator is the center and largest circle of these horizontal lines. • The equator divides Earth into the Northern Hemisphere and the Southern Hemisphere. Reading Maps (cont.) • Parallel circles are drawn at every degree north and south of the equator. These lines are referred to as lines of latitude. • The North Pole and the South Pole are each indicated by a dot at 90° N and 90° S. • A location’s latitude is the distance in degrees north or south of the equator. Reading Maps (cont.) Together, longitude and latitude are used to pinpoint a location on Earth. Reading Maps (cont.) What relationship do lines of longitude and lines of latitude have? Plotting Locations • Any location on Earth can be described by the intersection of the closest line of latitude and the closest line of longitude. • Because longitude and latitude lines are far apart, we divide each degree into 60 minutes (') and each minute into 60 seconds (") to help pinpoint locations. Plotting Locations (cont.) How do latitude and longitude describe a location on Earth? Time Zones • Time zones were created to make travel and doing business easier for everyone. • A time zone is the area on Earth’s surface between two meridians where people use the same time. Time Zones (cont.) The width of a time zone is 15° longitude, but they are sometimes altered at political boundaries. Time Zones (cont.) • The International Date Line is the line of longitude 180° east or west of the prime meridian. • When you cross the date line from east to west, it is a day later. • The International Date Line does not follow the 180° meridian exactly, because some island groups would be divided by the line. Map Projections • One way to transfer features from a globe to a flat map is to make a projection. • There are two types of projections that can be used to transfer features from a globe to a flat map: cylindrical projections and conical projections. Map Projections (cont.) Both cylindrical and conical projections result in some distortion. Map Projections (cont.) What are the advantages and disadvantages of cylindrical projections and conical projections? • Finding locations on a map or a globe can be done accurately by using grid lines called longitude and latitude. • Different projections offer different solutions to the distortion problem of transferring three dimensions into two dimensions. Which of these describes a view drawn as if you were looking down on an area from above Earth’s surface? A. earth view C. aerial view B. legend view D. map view What do model builders use to make model measurements accurate to the measurements of the real object? A. size C. scale B. weight D. legend Which of these terms refers to the distance in degrees north or south of the equator? A. longitude B. latitude C. scale D. ratio Do you agree or disagree? 1. Maps help determine locations on Earth. 2. All Earth models are spherical. 3. World maps are drawn accurately for every location. Technology and Mapmaking • What can a topographic map tell you about the shape of the Earth’s surface? • What can you learn from geologic maps about the rocks near Earth’s surface? • How can modern technology be used in map making? Technology and Mapmaking • topographic map • slope • elevation • geologic map • relief • cross section • contour line • remote sensing • contour interval Types of Maps A topographic map shows the detailed shapes of Earth’s surface, along with its natural and human-made features. topography from Greek topos, means “place”; and graphein, means “to write” Types of Maps (cont.) A topographic map helps give you a picture of what the landscape looks like without seeing it. Robert Glusic/Getty Images Types of Maps (cont.) • The height above sea level of any point on Earth’s surface is its elevation. • The difference in elevation between the highest and lowest point in an area is called relief. Types of Maps (cont.) Contour lines are lines on a topographic map that connect points of equal elevation. Types of Maps (cont.) • The elevation difference between contours that are next to each other is called the contour interval. • Slope is a measure of the steepness of the land. Types of Maps (cont.) • If the contours are spaced far apart, the slope is gradual or flat, but if the contours are close together, the slope is steep. • The information contour lines provide on a topographic map can be used to draw an accurate profile of the topography. Types of Maps (cont.) What can you learn about the features at Earth’s surface from studying contour lines? Types of Maps (cont.) • Geologic maps show the surface geology of the mapped area and may include rock types, their ages, and locations of faults. • On a geologic map, different colors represent different geologic formations. • A geologic formation is a volume of a particular kind of rock. Geologic Map Types of Maps (cont.) A cross section is a diagram showing a vertical slice through the rocks below the surface. Types of Maps (cont.) How is color used in a geologic map? Making Maps Today • Mapmakers and explorers first used instruments such as a compass, a telescope, or a sextant. • Today, mapmakers use computers and data from satellites to make maps. Making Maps Today (cont.) The Global Positioning System (GPS) is a group of 24 satellites orbiting Earth used for navigation. Making Maps Today (cont.) • The signals relayed by GPS satellites are used to calculate the distance to the satellite based on the average time of the signal. • GPS is used by mapmakers to accurately locate reference points. Making Maps Today (cont.) How can GPS technology be used in mapmaking? Making Maps Today (cont.) • Geographic Information Systems (GIS) are computerized information systems used to store and analyze map data. • GIS creates different map layers of the same location using database view, map view, and model view. Making Maps Today (cont.) GIS combine data collected from many different sources, including satellites, scanners, and aerial photographs. Making Maps Today (cont.) • Remote sensing is the process of collecting information about an area without coming into physical contact with it. • Remote sensing produces maps that show detailed information about agriculture, forestry, geology, land use, and many other subjects. Making Maps Today (cont.) • Satellite images of a location made at different times can be used to study change. • Monitoring change with remote sensing allows mapmakers to quickly make maps of areas affected by natural disasters. Making Maps Today (cont.) How can remote sensing be an advantage to mapmakers? Making Maps Today (cont.) • Several different remote sensing systems are currently used to map Earth’s surface. • Landsat 7 is a group of satellites that completes a scan of Earth’s entire surface every 16 days. Making Maps Today (cont.) • A pair of satellites—TOPEX and its successor, Jason-1—have been used to determine ocean topography, circulation, sea level, tides, and now climate change. • A device that uses sonar to map the bottom of the ocean is called Sea Beam. • Topographic maps use contour lines to help describe the elevation and relief of the surface of Earth at that spot. • Geologic maps are useful in determining the kind of rocks, the age of rocks, and the formations they are found in for an area. What is the height above sea level of any point on Earth’s surface called? A. slope B. contour interval C. elevation D. cross section Which diagram shows a vertical slice through the rocks below the Earth’s surface? A. geologic map B. cross section C. contour line D. topographic map Which term refers to the process of collecting information about an area without coming into physical contact with it? A. navigation B. mapping C. modeling D. remote sensing Do you agree or disagree? 4. Topographic maps show changes in surface elevations. 5. The colors on geologic maps show the colors of the surface rocks. 6. Satellites are too far from Earth to collect useful information about Earth’s surface. Key Concept Summary Interactive Concept Map Chapter Review Standardized Test Practice Earth’s features are measured using remote sensing, primarily from satellites. Earth’s features are modeled through map projections, topographic maps, and geologic maps. Lesson 1: Maps • A globe represents Earth’s surface without distortion. • Maps contain information, such as legends with identifying symbols, and latitude and longitude to determine location. • Map projections distort Earth’s features. Lesson 2: Technology and Map Making • Topographic maps show elevation through contour lines. • Geologic maps contain information about rocks such as rock types, rock age, and faults. • GPS, GIS, and remote sensing are used to check locations, take aerial photographs and images, and layer items to produce more accurate maps. Which of these refers to the distance in degrees east or west of the prime meridian? A. latitude B. longitude C. scale D. time zone What is the name for the line of longitude 180° east or west of the prime meridian? A. time zone B. equator C. International Date Line D. degree What is the difference in elevation between the highest and lowest point in an area is called? A. slope B. topography C. relief D. elevation What feature of a topographic map connects points of equal elevation? A. contour lines B. cross sections C. contour intervals D. geologic maps Which term refers to the elevation difference between contours that are next to each other? A. slope B. contour interval C. steepness D. relief Which term refers to the key that lists all the symbols used on the map to help you interpret the symbols? A. map key B. map scale C. profile view D. map legend What is the center line of latitude? A. prime meridian B. longitude C. equator D. legend The area on Earth’s surface between two meridians where people use the same time is which of these? A. a time zone B. the International Date Line C. the Northern Hemisphere D. the prime meridian Which term is a measure of the steepness of land? A. contour B. slope C. elevation D. topography Which term refers to the elevation difference between contours that are next to each other? A. the Geographic Information System B. sonar C. the Global Positioning System D. the contour interval