Chapter 2 Mapping our World Section 2 1

Chapter 2 Mapping our World

Section 2. 1 Latitude and Longitude You will be able to. . . Longitude • Compare and Contrast latitude and longitude. Latitude • Describe how time zones vary.

The science of mapmaking is called cartography. Lines of latitude are parallel. The latitude of the north pole is 90° north.

Longitude – Lines of longitude converge at the poles. The prime meridian represents 0° longitude.

Minutes Each degree of latitude or longitude is divided into 60 smaller units called minutes.

Seconds Each minute of latitude or longitude is divided into 60 smaller units called seconds.

Scale Each degree(°) = 111 km Each Minute(‘) = 1. 85 km And Each Second(“) = 30. 83 m Note: works for latitude only

Time Zones Earth is divided into 24 time zones.

International Date Line The International Date Line is another name for the 180° meridian.

International Date Line Traveling West ( ) across the International Date Line, you would advance your calendar one day. Sept. 1 Sept. 2 West

International Date Line Traveling East ( ) across the International Date Line, you would move your calendar back one day. Sept. 1 Aug. 31 East

Section 2. 2 Types of Maps You will be able to. . . • Compare and Contrast different map projections. • Analyze topographic maps. • Describe map characteristics such as map scales and map legends.

Distortion All flat maps distort either the shapes or the areas of landmasses because Earth is a curved, three-dimensional object.

Mercator A Mercator projection distorts areas near the poles. (the areas of landmasses near the poles are exaggerated)

Conic In a conic projection, there is very little distortion along one line of latitude, but the areas and shapes of landmasses near the top and bottom of the projection are distorted.

Gnomonic In a gnomonic projection, the direction and distance between landmasses are distorted. Polar Gnomonic Equatorial Gnomonic Oblique Gnomonic Gnomonic projection are used by navigators to plot great-circle routes.

Topographic map a type of map that shows changes in elevation of Earth's surface

Contour Interval Each contour line should represent one elevation. If two lines cross, it means that the point where they cross has two elevations, which is impossible. The difference in elevation between two side-byside contour lines is called the contour interval.

Legend & Scale A map legend explains what the symbols on a map represent. A graphic scale is a line broken into sections that represent units with each section representing a distance on Earth’s surface.

Section 2. 3 Remote Sensing You will be able to. . . • Compare and Contrast different 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

Light/Electromagnetic Spectrum The frequency of an electromagnetic wave is the number of waves that pass a particular point each second.

Speed of Light The speed of light in a vacuum is 300, 000 km/s.

Remote Sensing The process of collecting data about the Earth from above the surface. (Generally using the electromagnetic spectrum. )

GPS - Global Positioning System allows its users to determine their exact position on Earth.

GPS satellites can relay information about all of the following: • Direction • Elevation • Position

Landsat and Topex/Poseidon Both Landsat satellite and Topex/Poseidon satellite collect data about Earth by remote sensing. Topex/Poseidon Satellite Uses radar to map features on the ocean floor. Landsat Satellite Detects energy related to the warmth of surface features.

NOVA Science Now (time-out) Hyperlink on picture

Mapping Exercise Earth is a circle which has 360 degrees (◦) Each degree (◦) is divided into 60 minutes. Each minute is divided into 60 seconds Each degree(°) = 111 km Each Minute(‘) = 1. 85 km And Each Second(“) = 30. 83 m

Traveling When You Know your starting coordinates and the distance you travel (+) add 40° 45’ 16” , I travel 10’ 10” 40° 55’ 16” , I travel 10’ 10”

Distance between When You Know your starting coordinates and ending coordinates (-) subtract 40° 45’ 16” , Start 40° 55’ 16” , start 40° 20’ 15” Stop 39° 10’ 40” stop

Conversion When You need to convert degrees, minutes, seconds to a decimal Generally make it a fraction over 60 and add to the number to the left. 120° 40’ 25” =

Map Exercises http: //geology. isu. edu/geostac/Field_Exercise/topomaps/exercise_1. htm