Mapping Our World
 Cartography
 The science of mapmaking.
 What is the equator?
 Divides the Earth into Northern and
Southern Hemispheres.
 Latitude

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
Run parallel N & S of the equator.
90° N is the max (North pole)
90° S is the max (South pole)
Each degree is about 111 km. The Earth is
about 40 000 km, so divide by 360 to get
the 111 km.
The degrees can be broken down into
minutes (’), which are 60 units smaller than
degrees. One minute is 1.85 km, take 111
km divided by 60 to get this.
Minutes can be broken down into seconds
(”), which are 60 units smaller than
minutes.
Longitude
Runs through Greenwich, England.
Distance in degrees E or W of the prime
meridian.
Longitude is also divided into degrees,
minutes, and seconds.
Line of longitude are not parallel to one
another like latitude are. Each longitude
line connects to the N & S poles.
Example: Fig. 2-3 (pg. 30) New Orleans
29°57’ N & 90°04’ W
Time Zones
`
Why 24?
Fig. 2-4 (pg.30)
Fig. 2-5 (pg. 31)
International Date Line (180° meridan)
This is the transition line for calendar days.
If you travel West of it you gain a calendar
day and if you travel East you lose a day.
Types of Maps
•1. Mercator Projection – this map has
parallel lines of latitude and longitude.
•The landmass are the correct shapes, but
distorted.
•Ex. Greenland appears larger than Australia.
•Used for planes and ships
•Conic Projection – this map projects points
and lines from a globe onto a cone.
•There is less distortion except at the top and
bottom.
•Used for road maps and weather maps.
•3. Gnomonic Projection – the projection
points and lines from a globe are placed
onto a piece of paper that touches the
globe at a single point.
•4. Topographic Maps – used to show
changes in elevation on the Earth’s surface.
•Fig. 2-8 (pg.33)
•This map distorts direction and distance, but
they are useful in plotting long-distance trips
by air and by sea.
•Shows detail for hills and valleys in an area.
•The change in elevation is shown with contour
lines.
•Contour lines never cross.
•The lines connect points of equal
elevation.
•The difference in elevation between two
side-by-side contour lines are contour
intervals.
•Ex. If the contour intervals are close together
that means a steep elevation increase.
•Fig. 2-9 (pg. 34)
•Index contours are used as marked
numbers to represent the distance in an
increase or decrease of elevation.
•Most index contours are 5m or 10m.
•To show depression contour lines
(decrease in elevation), a short line at right
angles to the contour line is used. These
are called hachures.
•Fig. 2-10 (pg. 34)
•Map Legends
•Used to explain the symbols used for
representation.
•Fig. 2-11 (pg. 35)
•Map Scales
•Used as a ratio between distances on a map
and actual distances on the surface of Earth.
•The 3 types are verbal, graphic, and fractional.
•The verbal scale is represented by
expressed distances.
•Ex. One cm = One km
•The graphic scale uses a line that
represents a certain distance, such as 10
miles or 10 km.
•The line used could be broken down into
sections.
•The fractional scale shows distance as a
ratio.
•Ex. 1:2,847,000 or 1inch = 45 miles
•A large ratio represents a large area and a
small ratio represents a small area.
•Fig. 2-12 (pg. 36)
Remote Sensing
•With new technology scientists are able to
use remote sensing to map the Earth’s
surface.
•Electromagnetic Spectrum
•All electromagnetic waves travel at 300 000
km/s in a vacuum.
•What are the electromagnetic waves?
•Radio, microwaves, infrared, visible, U.V., x-rays,
gamma.
•Landsat Satellites
•Use receives wavelengths of energy from
Earth (mainly visible & infrared).
•Fig. 2-15 (pg.38)
•Topex/Poseidon Satellite
•It uses high-frequency radar to map the ocean
floor.
•Fig. 2-16 (pg. 39)
•Global Positioning System (GPS)
•A radio-navigation system used to determine
exact positions on Earth.
•There are over 24 satellites that orbit the
Earth. They use a high-frequency microwave
to pick up transmissions from the GPS unit.
•GPS units calculate exact longitude and
latitude, along with elevation, speed, and
direction of the unit.