MAPPING OUR
WORLD
MAPPING

Cartography• science of map making
Maps
*Flat models of 3-dimensional
spaces
**Earth is always distorted on maps
Typical Graph



This is an example of a
typical graph we are all
familiar with.
The graph is made
up of different
“points” with lines
that connect
the points.
The points are
referenced to the x
and y axis
Maps are Similar to Graphs
N

W
E
S
Let each of the
four quarters be
designated by
North or South
and East or West.
What are the 0 points?

Equator –
• Separates the Earth into two equal halves
called the northern hemisphere and the
southern hemisphere
• It is an imaginary belt that runs halfway
point between the North Pole and the
South Pole.
Equator
What are the O points? P M

Prime Meridian –
• Divides the Earth running
North -South
• Separates the Earth into two
halves – the Eastern hemisphere
and the Western hemisphere
• Goes through Greenwich,
England – home of Royal Naval
Observatory
E
R
I I
D
M
I
E A
N
R
East West, North South on the
Earth
(N, W)
(N, E)


(S, W)
(S, E)
The N tells us we’re
north of the Equator.
The S tells us we’re
south of the Equator.
The E tells us that
we’re east of the
Prime Meridian. The
W tells us that we’re
west of the Prime
Meridian.
Latitude and Longitude

The earth is divided into lots of
reference lines called latitude and
longitude.
What is Latitude?

90°N
Y


X

90°S



Latitude is the distance
from the equator along
the Y axis.
Lines running parallel to
equator
Measures NORTH –
SOUTH, but runs EastWest
All points along the
equator have a value of 0
degrees latitude.
North pole = 90°N
South pole = 90°S
Values are expressed in
terms of degrees.
What is Latitude?
Each degree of
latitude is divided
into 60 minutes.
 Each minute is
divided into 60
seconds.
X
 Ex: coordinates of
Sunny Hills HS
33°52′48″N
117°55′43″W

90°N
Y
90°S
This is also true of longitude.
What is Longitude?


Y

X


180°W
180°E
Longitude is the distance
from the prime meridian
along the X axis.
Lines running parallel to
Prime Meredian
Measures EAST – WEST,
but runs North-South
All points along the prime
meridian have a
value of 0 degrees
longitude.
The earth is divided into
two parts, or
hemispheres, of east and
west longitude.
What is Longitude?

Y
X
180°W
180°E

The earth is divided
into 360 equal
slices
(meridians)
180 west and 180
east of the prime
meridian
The Size of 1o

Latitude
• degree of latitude is approximately 69 miles,
and a minute of latitude is approximately 1.15
miles

Longitude
• A degree of longitude varies in size – it
decreases to zero as meridians come together
at the poles
• At the equator, it is approximately 69 miles,
the same size as a degree of latitude.
• At a latitude of 45 degrees, a degree of
longitude is approximately 49 miles.
Coordinate System
Time Zones

The Earth is divided into 24 time zones
• Each time zone is 15˚ wide
• There are 6 different time zones in the U.S.
Rotation



The Earth rotates 15o of longitude
every hour
24 lines of longitude (24 hours) in
one day
15 x 24 = 360o total (full circle)
• 180o longitude on each side of Prime
Meridian
International Date Line

The International Date Line, or 180˚
meridian, serves as the transition
line for calendar days
• If you were traveling west across the
IDL, you would advance your calendar
one day.
• If you were traveling east across the
IDL, you would move your calendar
back one day.
See If You Can Tell In Which
Quarter These Lon/Lats Are
Located


A
B


C
D


1.
2.
3.
4.
5.
6.
41°N, 21°E
37°N, 76°W
72°S, 141°W
7°S, 23°W
15°N, 29°E
34°S, 151°E
1.
 2.
 3.
 4.
 5.
 6.

B
A
C
C
B
D
Mercator Projection

Parallel lines of latitude and longitude
• Area of land masses near the poles are
exaggerated

Used for navigation of planes and ships
Conic Projections


Points and lines on a globe are
projected onto a cone-shaped paper.
Little distortion in the areas or shapes
of landmasses that fall along this line
of latitude
• Distortion is evident
near top and bottom of
the projection
• Useful for road maps
& weather maps
Gnomonic Projections

Points and lines from a globe are
projected onto a paper that touches
the globe at a single point.
• Distort direction and distance between
landmasses
Useful in plotting
long-distance trips by
air and sea

Topographic Maps
Topographic Map


Show changes in elevation of Earth’s
surface
Also show, mountains, rivers, lakes,
forests, etc.
Features of Topographic Maps
Relationship between 3D and 2D representation
3D view
2D view
Contour Lines
• Contour lines drawn on
a map give the elevations
for a region.
• Where the lines are
close, the slope of the
ground is steep.
• Where the lines are far
apart, the slope of the
ground is gentle.
Contour Lines

Imaginary lines that connects points
of equal elevation (height above sea
level)
Contour Lines


contour lines do not intersect, branch
or cross, except in a vertical or
overhanging cliff.
When contour lines cross a stream,
they form a “V” with the point of the
V pointing upstream
Contour Interval


The
difference in
elevation
between two
side-by-side
lines
Each map
has a unique
contour
interval, so
locate label
on the map
Index Contours
• Some contour lines
are marked by
numbers
representing their
elevations.
• Practice!
• What is the
elevation of the
line that is left of
the 100m index
contour.
Depression Contour Lines
When the
elevation
is lower
than the
surroundin
g area
there are
“hachures”
on the line

Contour Map Example
On this map, the vertical distance between each of the contour lines
is 10 feet.
1.Which hill is higher,
hill A or hill B?
2.Which hill is steeper,
hill A or hill B?
3.How many feet of elevation
are there between contour
lines?
4.How high is hill A? Hill B?
5.Are the contour lines closer
on hill A or hill B?
Map Legends

A map legend explains what the
symbols on a map represent
Map Scales
Definition
A means of showing the relationship between the
size of an object indicated on a map and the actual
size of the object on the surface of Earth.
Scale Types
Fractional scale: - is a fixed ratio between linear measurements on
the map and corresponding distances on the ground.
Example: 1:62,500
Graphical scale: - is simply a line or bar drawn on the map and
divided into units
that0 represent
ground
distances.
1
1
2
3
4 Miles
Example:
Verbal scale: - is a convenient way of stating the relationship of
map distance to ground distance.
Example: 1 inch equals 1 mile
Remote Sensing
• The Electromagnetic Spectrum
 The arrangement of electromagnetic
radiation according to wavelengths
• Frequency
 refers to the # of waves that pass a
particular point each second
Wave Characteristics
• Electromagnetic waves travel at
the speed of 300,000 km/s in a
vacuum
“The Speed of Light”
Topex/Poseidon Satellites



An emitter sends outgoing signal to the
surface of the ocean
A receiver times the
returning signal
Distance to ocean’s
surface is calculated
using the known
speed of light and the
return time.
Landsat Satellite

Receives
reflected
wavelengths of
energy emitted
by Earth’s
surface, such as
rivers and
forests
GPS


A radio-navigation
system of at least 24
satellites that allows
its users to determine
their exact location on
Earth.
The receiver calculates
the user’s precise
lat/long by processing
the signals emitted by
multiple satellites.
Sea Beam



Used to map the
ocean floor
Located on a ship
rather than a satellite
Uses sonar which is
the use of sound
waves to detect and
measure objects
under water.