Maps and Map Skills Kinds of Maps General

Maps and Map Skills

Kinds of Maps • General Reference Maps • Provide the reader general information about an area or place. • Thematic Maps • Provide more specific information about an area or place than general reference maps.

General reference

Thematic Map

• Maps are important tools for geographers. • A globe is a better model of Earth than a map, but a globe has disadvantages that a map does not have

Reading Maps • Map Parts • Title • Legend or Key • Grid System • Direction • Scale • Map orientation – This has to do with direction

Compass Title Scale

Large Scale and Small Scale Maps • A large-scale map shows a small area such as a neighborhood street in great detail. • A small-scale map shows a large area such as a country or a continent in comparatively lesser detail. Small Area = Large Scale Large Area = Small Scale

Large Scale Small Area = Large Scale Large Area = Small Scale

Compass • Is used to orient a map toward north

Latitude and Longitude

• Latitude • The set of lines crossing the Earth’s surface horizontally, Circling east and west. • Each line of latitude is always an equal distance from the next. • They are also known as parallels. All latitude lines are parallel to each other

• Longitude • A set of lines that run vertically along Earth’s surface from the North Pole to the South Pole

Global Grid • When lines of latitude and longitude cross a grid is formed. The grid is used to located certain places on earth

• Each line has an Identifying number called 0 degrees, or parts of a circle. (41 ) • Degrees, can be further divided into minutes, or parts of a degree. There are 60 minutes, or parts of a degree. (10’) • Minutes can be divided into even smaller parts called seconds. There are 60 seconds in each minute. (10”) 0 • 41 10’ 10” Degrees 41 0 Minutes 10’ Seconds 10”

Direction • The other part needed to locate places on Earth is direction. • Cardinal directions are: north, south, east, and west. • Intermediate directions are: northeast, southeast, northwest, and southwest. They are located midway between the cardinal directions.

Using Latitude & Longitude to Locate Places • Lines of latitude are numbered based on how far north or south they are from an imaginary line called the equator • This line circles the Earth exactly halfway between the NP and SP. 0 • The equator’s latitude degree is 0. There are 90 degrees between it and each of the poles. • Area between the equator and NP is “north” latitude 0 (22 N) • Area between the equator and SP is “south” latitude 0 (22 S)

• Lines of longitude are numbered based on how far east or west they are from another imaginary line. • This line is called the Prime Meridian. 0 • Prime Meridian’s longitude degree is 0. 0 0 • There are 180 of longitude east of the PM and 180 degrees west of it. • Area east of the PM is known as “east” longitude. 0 (120 E) • Area west of the PM is known as “west” longitude. 0 (120 W)

Prime Meridian & International Date Line • The prime meridian does not circle the globe as the equator does. • The PM runs from the NP to SP 0 • At 180 on the other side of the globe the meridian is called the international date line.

Hemispheres • The earth can be divided into halves. Each of these halves is called a hemisphere

Hemispheres at the Equator • The ½ north of the equator is called the northern hemisphere • The ½ south of the equator is called the southern hemisphere

Hemispheres at Prime Meridian and International Date Line • Earth can also be divided into hemispheres at the circle formed by the prime meridian and International date line • The ½ east of the prime meridian is called the eastern hemisphere. • The ½ west of the prime meridian is called the western hemisphere.

Making Maps • • • Gathering Information Problem of Distortion Map Properties Map Projections Cartographers (Mapmakers)

Gathering Information • • • Surveying Aerial Photography (Air Planes) Remote Sensing (Satellites)

Problem of Distortion • Features are stretched to put Earth’s information onto a map.

Map Properties • No map can have all of the properties at once • • Equal areas Conformality Consistent Scale True-Compass Directions

• Equal areas • Places shown have the same proportions as they do on Earth. • Example: Greenland 1/8 land area of S. America

• Conformality • • • Having correct shapes. Shows true shapes. Can show larger areas as closely as possible to their true shapes

• Consistent Scale • • • Uses the same scale for all parts of the map. Shows the true distances between places on Earth In most Cases maps showing large areas cannot be consistent-scale maps.

• True-Compass Direction • Parallels and meridians appear as straight lines. • By following these lines you will be following the cardinal directions of N, S, E, &W. • Straight line between two points on map determines exact directions and set course. (Navigators use these maps)

Map Projections • • • Cylindrical Projections Conic Projections Flat Plane Projections Gnomonic Projection Robinson Projection Goode’s Interrupted

Cylindrical Projections • Straight lines of latitude and Longitude are Perpendicular • Little distortion near the equator • Best Known: • Mercator – • conformal and true-compass direction map, but distortion near poles makes size of land water areas inaccurate. Land shapes correct – areas distorted – valuable to navigator

Conic Projections • Cannot map the entire world. 0 0 • Used for middle latitudes between 30 and 60 north 0 0 latitudes, and between 30 and 60 south latitudes • Best Known: • Lambert Conformal Conical • Important because it shows the true shapes of areas. • Albers Equal Area Conical • Consistent scale and is used when the size of land water areas must be accurate. (military and engineering maps)

Flat Plane Projections • Used to map areas of the North and South poles. Areas near that point show little distortion • Farther away from the point the greater the distortion of area, shape, and scale. • Shows no more that ½ of the Earth at one time. • Also called Azimuthal Projection

Gnomonic Projection • Circles of latitude lines and straight longitude lines form a wheel-like pattern. • Especially useful to navigators because the shortest distance between two places on the map is found by drawing a straight line between them {this line is actually a part of a great circle – any imaginary line that circles Earth and divides it into 2 equal parts • Navigators use these along with true-compass direction maps to make their travel plans.

Robinson Projection • Equal areas – shown with high degree of accuracy • Conformal except near edges of map where distortion increases • Valuable for showing entire world.

Goode’s Interrupted • High degree of accuracy in area and shape • Distorted direction and scale. • Valuable for showing Land masses.

Points to Remember • The projection one chooses to use depends on the information one wants. • All Maps are projections – they transfer Earth’s features from the globe to a flat surface (map). • When large areas of Earth are mapped, distortion is more serious. • When mapping small areas like cities, distortion is not usually evident.