Mapping Our World Chapter 2

Transcription

1 Mapping Our World Chapter 2 Section 2.1: Latitude and Longitude Maps are flat models of threedimensional objects. For thousands of years people have used maps to define borders and to find places. With new technology, there is more information available to create more accurate maps. Objectives Describe the difference between latitude and longitude. Explain why it is important to give a city s complete coordinates when describing its location. Explain why there are different time zones from one geographic area to the next. TIME ZONE = a geographic region within which the same standard time is used. Latitude: The science of mapmaking is called cartography Cartographers use an imaginary grid of parallel lines to locate exact points on Earth. The equator horizontally circles Earth halfway between the north and south poles. It also separates the earth into two equal halves called the northern hemisphere and the southern hemisphere. 1

2 Latitude: Lines on a map running parallel to the equator are called lines of latitude. Latitude is the distance in degrees north or south of the equator. The equator, which is a reference point for latitude is numbered 0 latitude Latitude is the labeled 0-90 N or S of the equator. Latitude: Each degree of latitude is equivalent to about 111 km on Earth s Surface. Longitude: To locate positions in east and west directions, cartographers use lines of longitude (meridians). Longitude is the distance in degrees east and west of the prime meridian The prime meridian is the reference point for longitude and runs through Greenwich, England (0 longitude) 2

3 Longitude: Lines of longitude extend vertically, intersecting at both the north and south poles. Points west of the prime meridian are numbered from 0 to180 W longitude. Points east of the prime meridian are numbered from 0 to180 E longitude. Longitude: Distances between longitudes varies depending on the location on Earth. Each degree of longitude is anywhere from 111 km at the equator to 0 km at the poles. 3

4 Precise Positions To locate positions more precisely, cartographers break down degrees into smaller units called minutes. 1 = 60 Time Zones: Earth is divided into 24 time zones. Why 24? Each time zone is 15 wide Adjacent time zones an hour apart (+/-) 4

5 International Date Line The international dateline, at 180 meridian, serves as the transition line for calendar days. It is the point where East and West longitude meet. When crossing from W longitude to E longitude, the calendar day is set forwards. 8/27 8/26 Using Coordinates Both latitude and longitude are needed to located precise positions on Earth. Coordinates are written with latitude first, followed by longitude. Ex: 40 N, 87 W 40 N, 87 W 5

6 35 14 N, W Latitude, Longitude Consider the Following: If City A is located at a latitude of 20 N, and City B is located at a latitude of 40 N, how far apart are these cities in kilometers? 1 Lat. = 111 km 20 x 111 km = 2220 km apart Section 2.2 Types of Maps Projections Because Earth is spherical, it is difficult to represent on a piece of paper. Cartographers use projections to make maps. Projections are made by transferring points and lines on a globe onto a sheet of paper. 6

7 Mercator Projection A Mercator projection is a map that has parallel lines of latitude and longitude. When longitudinal lines are projected as parallel lines, landmasses near the poles are exaggerated. Conic Projection A conic projection is made by projecting points and lines from a globe onto a cone Very little distortion of area or shape of landmass. Some distortion near top and bottom of projection. Excellent for mapping small areas. 7

8 Gnomonic projections A gnomonic projection is made by projecting points and lines from a globe onto a piece of paper that touches the globe at a single point. 8

9 Topographic maps Topographic maps show changes in elevation of Earth s surfaces. They also show mountains, rivers, forests, bridges, ect Topographic maps use lines, symbols, and colors to represent changes in elevation. 9

10 Topographic Maps Contour lines: connect points of equal elevation. (never cross) Contour interval: The difference in elevation from one contour line to the next. Index contours: Contour lines marked with a number to represent the elevation. Depression contour lines: used to represent craters and mines. Topographic Maps Topographic Maps Topographic Maps 10

11 Geologic Maps Geologic maps are used to show the distribution, arrangement, and type of rocks located below the soil. A geologic map can also show features such as fault lines, bedrock, and geologic formations. Three-Dimensional Maps Computers are used to digitize features such as rivers, mountains, valleys, and hills. 11

12 Map Legends Map legends explain what the symbols found on a map represent. Map Scale The ratio between distances on a map and actual distance on earth Map Scale Verbal Scales, Graphic Scales, and Fractional Scales Section 2.3 Remote Sensing 12

13 Remote Sensing Advanced technology has changed the way maps are made. The process of gathering data about Earth using instruments on satellites, airplanes, or ships is called remote sensing. Types of Remote Sensing There are three main ways remote sensing is achieved. Landsat Satellite TOPEX/Poseidon satellite (radar) (Now OSTM/Jason) Sea Beam (sonar) Landsat Satellite Landsat Satellite Landsat satellites record reflected wavelengths of visible and infrared light from Earth s surface. Landsat satellites can scan the entire surface of Earth in 16 days. Landsat data is used to study the movements of Earth s plates, rivers, earthquakes, and pollution. 13

14 TOPEX/Poseidon Satellite Uses radar to map features on the ocean floor, global sea level, and global ocean currents. Ended mission in 2006 OSTM/Jason OSTM/Jason-2 is the current mission to take the place of TOPEX/Poseidon Ocean Surface Topography Mission Radar uses radio waves. Sea Beam Located on a ship Relies on sonar (sound waves) Makes detailed 3D topographical maps of the ocean floor. 14

15 GPS Stands for Global Positioning System. Satellite navigation system that allows users to locate their approximate position on Earth. GPS GPS requires three satellites to triangulate your location. Network of 31 satellites 15

16 GIS Stands for Geographic Information System. Uses many of the traditional types and styles of mapping and overlays them. Test Review According to the Table, which city is farthest north? 16

17 What is another name for 0 longitude? A.Equator B.International Date Line C.Tropic of Cancer D.Prime Meridian What is another name for 0 longitude? A.Equator B.International Date Line C.Tropic of Cancer D.Prime Meridian What type of projection has parallel lines of longitude and latitude. A.Gnomonic B.Mercator C.Conic D.Topographic What type of projection has parallel lines of longitude and latitude. A.Gnomonic B.Mercator C.Conic D.Topographic 17

18 What does GPS stand for? A.Global Potential Satellite B.Graphic Positioning System C.Global Positioning Satellite D.Global Positioning System What does GPS stand for? A.Global Potential Satellite B.Graphic Positioning System C.Global Positioning Satellite D.Global Positioning System What does the red line on the following map represent? What type of map is shown in the following diagram? The Equator (0 Latitude) Topographic Map 18

19 What type of map shows the distribution of rock types? What type of map shows the distribution of rock types? A.Geographic Map B.Geologic Map C.Gnomonic Map D.GIS Map A.Geographic Map B.Geologic Map C.Gnomonic Map D.GIS Map What is another name for lines of longitude? What is another name for lines of longitude? A.Meridians B.Equatorials C.Mercators D.Landsats A.Meridians B.Equatorials C.Mercators D.Landsats 19

20 What does the following line represent? What technology does Sea Beam rely on? Prime Meridian (0 Longitude) A.X-ray B.Sonar C.Gamma Ray D.Ultraviolet What technology does Sea Beam rely on? In which hemisphere is the United States located? A.X-ray B.Sonar C.Gamma Ray D.Ultraviolet A.Upper Hemisphere B.Lower Hemisphere C.Northern Hemisphere D.Southern Hemisphere 20

21 In which hemisphere is the United States located? A.Upper Hemisphere B.Lower Hemisphere C.Northern Hemisphere D.Southern Hemisphere 21