Chapter 1
A framework of lines that helps to
transfer points on Earth’s surface onto a
flat map.
map projection
The size and shape of landmasses become
more distorted toward the north and
south poles on this type of projection.
Mercator projection
One half of the sphere that makes up
Earth’s surface.
hemisphere
A list of symbols used on a map and
their meanings.
key
A spherical model of Earth’s entire
surface.
globe
This is how many degrees you travel if
you circle the globe completely and
return to the spot form where you
departed.
360⁰
The distance in degrees north or
south of the equator.
latitude
This is the latitude of the North Pole.
90⁰
These are the units used by scientists
to locate positions on Earth’s surface.
degrees
The distance in degrees east or west
of the prime meridian.
longitude
Used to relate distance on a map or
globe to distance on Earth’s surface.
scale
A flat model of all or part of Earth’s
surface as seen from above.
map
The line that makes a half circle form
the North Pole to the South Pole and
that passes through Greenwich,
England.
prime meridian
An imaginary line that circles Earth
halfway between the North and
South poles.
equator
On a map, a picture used by
mapmakers to stand for features on
Earth’s surface.
symbol
One bit of a digitized image, often
appearing as a small square or dot.
pixel
A satellite-based system that can
precisely determine latitude and
longitude for points on Earth’s
surface.
Global Positioning System
(GPS)
This is how many satellites above the
horizon there must be at any given
time for the GPS to work.
At least 3
The difference in elevation from one
contour line to the next.
contour interval
A system of computer hardware and
software used to produce interactive
maps.
Geographic Information System
A photograph taken by cameras
mounted in airplanes.
aerial photograph
Converting information to numbers
for use by a computer.
digitizing
This is why computer mapmakers
digitize map data.
so they can display the data on
a computer screen
A line on a topographic map that
connects points of equal elevation
(the further apart these lines are, the
easier it is to walk up the slope).
contour line
On a topographic map, a heavier
contour line that is labeled with
elevation of that contour line.
index contour
A picture of the land surface based on
computer data collected from
satellites.
satellite image
A map that shows the surface
features of an area.
topographic map
The process of gathering data for a
map by using instruments and the
principles of geometry to determine
distance and elevations.
surveying
The difference in elevation between the
highest and lowest parts of an area.
relief
A landform made up of flat or gently
rolling land with low relief.
plain
This is the vast, flat or gently rolling
grassland in the interior of North
America.
Great Plains
A group of mountains that are closely
related in shape, structure, and age.
mountain range
A feature of topography formed by
the processes that shape Earth’s
surface (ex. hill, valley).
landform
A landform with high elevation and
high relief (ex. Rocky Mountains).
mountain
A large area of land where the
topography is made up mainly of one
type of landform.
landform region
The shape of the land determined by
elevation, relief, and landforms.
topography
A landform that has high elevation
and a more or less level surface.
plateau
Height above sea level and also one
of the major differences between a
coastal plain and an interior plain.
elevation
This is shown on a topographic map
by hachured contour lines.
depression