Page 75 - Geosystems An Introduction to Physical Geography 4th Canadian Edition

looking for additional review and test prep materials? Visit the Study Area in MasteringGeographyTM to enhance your geographic literacy, spatial reasoning skills, and understanding of this chapter’s content by accessing a variety of resources, including interactive maps, geoscience animations, satellite loops, author notebooks, videos, RSS feeds, web links, self-study quizzes, and an eText version of Geosystems.
Chapter 1 essentials of Geography 39
15. What and where is the prime meridian? How was the location originally selected? Describe the meridian that is opposite the prime meridian on Earth’s surface.
■ Define cartography and mapping basics: map scale and map projections.
A map is a generalized depiction of the layout of an area, usually some portion of Earth’s surface, as seen from above and greatly reduced in size. Cartography is the science and art of mapmaking. For the spatial portrayal of Earth’s physical systems, geographers use maps. Scale is the ratio of the image on a map to the real world; it relates a unit on the map to a cor- responding unit on the ground. When creating a map projection, cartographers select the class of projection that is the best compromise for the map’s specific pur- pose. Compromise is always necessary because Earth’s roughly spherical three-dimensional surface cannot be exactly duplicated on a flat, two-dimensional map. Relative abilities to portray equal area (equivalence), true shape (conformality), true direction, and true dis- tance are all considerations in selecting a projection. The Mercator projection is in the cylindrical class; it has true-shape qualities and straight lines that show constant direction. A rhumb line denotes con- stant direction and appears as a straight line on the Mercator.
map (p. 25)
cartography (p. 26)
scale (p. 26)
map projection (p. 27) equal area (p. 27)
true shape (p. 27) Mercator projection (p. 28) rhumb line (p. 28)
16. Define cartography. Explain why it is an integrative discipline.
17. Assess your geographic literacy by examining atlases and maps. What types of maps have you used: Political? Physical? Topographic? Do you know what map projections they employed? Do you know the names and locations of the four oceans, the seven continents, and most individual coun- tries? Can you identify the new countries that have emerged since 1990?
18. What is map scale? In what three ways may it be expressed on a map?
19. State whether the following ratios are large scale, medium scale, or small scale: 1:5000000; 1:10000; 1:25 000.
20. Describe the differences between the characteristics of a globe and those that result when a flat map is prepared.
21. What type of map projection is used in Figure 1.15? In Figure 1.19? (See Appendix A.)
■ Describe modern geoscience techniques—the Global Positioning System (GPS), remote sensing, and geographic information systems (GIS)—and explain how these tools are used in geographic analysis.
Latitude, longitude, and elevation are accurately measured using a handheld Global Positioning System (GPS) instru- ment that reads radio signals from satellites. Orbital and aerial remote sensing obtains information about Earth sys- tems from great distances without the need for physical contact. Satellites do not take photographs but instead re- cord images that are transmitted to Earth-based receivers. Satellite data are recorded in digital form for later process- ing, enhancement, and image generation. Aerial photo- graphs are used to improve the accuracy of surface maps, an application of remote sensing called photogrammetry.
Satellite and other data may be analyzed using geographic information system (GIS) technology. Com- puters process geographic information from direct ground surveys and remote sensing in complex lay- ers of spatial data. Digital elevation models are three- dimensional products of GIS technology. Open-source GIS is increasingly available to scientists and the public for many applications, including spatial analysis in geog- raphy and the better understanding of Earth’s systems.
Global Positioning System (GPS) (p. 30) remote sensing (p. 31)
photogrammetry (p. 31)
geographic information system (GIS) (p. 33)
22. What is GPS and how does it assist you in finding lo- cation and elevation on Earth? Give several examples of GPS technology used for scientific purposes.
23. What is remote sensing? What are you viewing when you observe a weather satellite image on TV or on the Internet? Explain.
24. If you were in charge of planning the human development of a large tract of land, how would GIS methodologies assist you? How might planning and zoning be affected if a portion of the tract in the GIS is a floodplain or prime agricultural land?
Answer for Critical Thinking 1.5, Figure CT 1.5.1: This natural, true-colour image is a composite mosaic of numer- ous images captured between 2000 and 2002 from NASA satellite Terra. The location it depicts is the meeting of the European and African continents at the Strait of Gibraltar, extending from France and Spain across the Mediterranean to Morocco and Algeria.