Geographical Themes and Terms

GEOGRAPHICAL THEMES AND TERMSChapter 1

TERMS TO KNOW• Absolute Location• Cardinal Directions• Cartography• Cartographers• Compass Rose• Continent• Contour Lines• Elevation• Elevation Profile• Equator• Geography• Grid System• Hemisphere

• Intermediate Directions• International Date Line• Latitude• Legend• Location• Longitude• Meridian• Movement• North Magnetic Pole• North Pole• Ocean• Parallel• Place

• Prime Meridian• Projection• Region• Relative Location• Relief• Scale• Scale Bar• South Magnetic Pole• South Pole

GEOGRAPHIC THEMES• The globe is the most accurate way to represent the Earth; however,

using one presents serious disadvantages:• The difficulty in carrying a globe around.• The inability of a globe to display your community in detail.

• For these reasons, cartographers use two-dimensional maps, which distorts the surface of the Earth that it represents.• Cartography is the study and practice of making maps.

• The different methods which cartographers have found to represent a globe on a flat surface are called projections.• The most common projections are the Mercator Projection, Goode’s

Interrupted Projection, and the Robinson Projection.

GEOGRAPHIC THEMES• The Mercator Projection is a cylindrical map projection created by the

Flemish geographer and cartographer Gerardus Mercator in 1569.• A cylindrical map projection displays land shapes fairly accurately, but is less

accurate in relation to size and distance.

• This projection became the standard map for nautical purposes because of its ability to represent lines of constant course.• All segments, parallels and meridians, are straight, not curved, and form

intersecting right angles.• The Mercator projection distorts the size and shape of large objects, as the

scale increases from the Equator to the poles, where it becomes infinite.• Additionally, this map projection does display true direction.

GEOGRAPHIC THEMES• Goode’s Interrupted Projection is an equal-area composite map

projection and is typically presented with multiple interruptions.• The interruption scheme emphasizes the world’s land masses not the world’s

oceans.• In other words, it accurately presents the size and shape of the continents

but is less accurate in relation to the distances of the oceans.

• This projection was developed in 1923 by John Paul Goode to provide an alternative to the Mercator Projection for portraying global areal relationships.

• Researchers use this type of projection to compare a continent’s statistics in relation to the area.

GEOGRAPHIC THEMES• The Robinson Projection was created because it was believed that it

produced a better overall view than the equal-area or cylindrical projections.

• This projection accurately displays both the size and shape of the continents and oceans – continental shapes appear much as they do on a globe.• The meridians curve gently, avoiding extremes, but thereby severely distorting

the North and South poles.

• The Robinson projection was devised by Arthur H. Robinson in 1963 in response to an appeal from the Rand McNally company, which has used the projection in general purpose world maps since that time.• Additionally, the National Geographic Society began using this projection in

1988, replacing the Van der Grinten projection.

GEOGRAPHIC TERMINOLOGY

• A compass rose is a device used to display the orientation of the cardinal directions and their intermediate points.

• The cardinal directions are the basic directions on Earth:• North (N), East (E), South (S), and

West (W)

• The intermediate directions fall between the cardinal directions:• Northeast (NE), Southeast (SE),

Southwest (SW), and Northwest (NW)


• The scheme which best divides Earth is known as a hemisphere.• A hemisphere, or “half sphere,” refers to the bi-partial division of the Earth.

• The most common divisions are by latitudinal and longitudinal markers:

• The Equator divides the northern and southern portions of the Earth.• The Northern Hemisphere is the half of the Earth that is north (above) of the Equator.• The Southern Hemisphere is the half of the Earth that is south (below) of the Equator.

• The Prime Meridian and International Date Line divide the eastern and western portions of the Earth.• The Eastern Hemisphere is the half of the Earth that is east of the Prime Meridian and

west of the International Date Line and consists of Africa, Asia, Australia, and Europe.• The Western Hemisphere is the half of the Earth that is west of the Prime Meridian and

east of the International Date Line and consists of the Americas, or the New World.

GEOGRAPHIC TERMINOLOGY• Parallels circle the Earth and

display latitude, which is the distance measured in degrees north and south of the Equator at 0° latitude.• The letter N or S following the degree

symbol indicates whether the location is north or south of the Equator.

• Important parallels to note are:• Tropic of Cancer – 23°30' N latitude • Tropic of Capricorn – 23°30' S latitude • Arctic Circle – 66°30' N latitude • Antarctic Circle – 66°30' S latitude


• The North Pole is the point on the Northern Hemisphere of the Earth that is the farthest north.• Its location is marked at 90° North

(N) latitude.

• The North Magnetic Pole is the point on the Northern Hemisphere of the Earth toward which a compass’ needle always directs.• At this location a compass’ needle

will stand vertically.

• The South Pole is the point on the Southern Hemisphere of the Earth that is the farthest south.• Its location is marked at 90° South

(S) latitude.

• The South Magnetic Pole is the point on the Southern Hemisphere of the Earth toward which a compass’ needle always directs.• At this location a compass’ needle

will stand vertically.

GEOGRAPHIC TERMINOLOGY• Meridians is a circular arc that run

north and south from pole to pole.

• These lines signify longitude, which is the distance measured in degrees east (E) or west (W) of the Prime Meridian at 0° longitude.• The Prime Meridian passes through

Greenwich, England.

• On the opposite side of the Earth is the International Date Line, or the 180° meridian.• The actual line used is not a straight line,

but zigzags around certain populated areas.

• The eastern side of the line is a calendar day earlier than the western side.


• Lines of latitude and longitude intersect one another in the form of a grid system, also referred to as a coordinate system.• Citizens of all countries, no matter

the culture, speak the universal language of latitude and longitude.

• Absolute location is the definitive location of a place using the recognized coordinate system.• In terms of latitude and longitude,

Florence, Alabama is 34°47' N and 87°40' W.


• A continent is a large landmass often described by means of tectonic plates.

• The seven commonly regarded continents are:• Africa• Antarctica• Asia• Australia• Europe• North America• South America

• An ocean is a large body of saline water that composes much of Earth’s hydrosphere.• The oceans combine to cover more

than two-thirds of the Earth’s surface.

• The five commonly regarded oceans are:• Atlantic Ocean• Artic Ocean• Indian Ocean• Pacific Ocean• Southern (Antarctic) Ocean


Parts of Maps• The legend unlocks the information

presented on a map by explaining the meaning of the symbols used.

• A scale is the proportional relationship between a linear measurement on the map and the distance it represents on the surface of the Earth.• The scale bar is a divided line

illustrating the scale in feet, miles, or kilometers.

Types of Maps• General purpose maps represent a

wide variety of general information.

• The most common general purpose maps are:• Political maps• Physical maps• Contour maps


Political Maps• Political maps display

political, or human-created, divisions of nations or regions.• Typically political entities

are separated by varying colors.

Physical Maps• Physical maps display the

physical features of an area.

• These types of maps use colors and shadings to better illustrate reliefs.

• A relief shows the elevations and depressions of the land or sea bottom.

• Colors also may be used to display elevation – the height of a point on the Earth’s surface above sea level.

Contour Maps• Contour maps display an

area’s elevation using contour lines, which connect all points of the same elevation with one line.• These lines typically form

circles or ovals – one inside the other.

• If the lines are close together, the surface is steep.

• If the lines are spread apart, the land is flat or rises gradually.

• Another way to display relief is to view the landscape from the side, or profile.• This elevation profile is a

cutaway diagram.

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Geographical Themes and Terms